A VERTICAL ENLARGER pRAC'TICAL9 ' MECHANICS

THIS TWIN -BEAM ENGINE, BUILT IN 1861, STILL PROVIDES POWER FOR A LARGE FACTORY. (See page 211)

PRINCIPAL CONTENTS

Armature Winding Model Aircraft Exhibition The World of Models Turret for a Small Lathe Remote -controlled Tank Letters from Readers Electrical Engineering Developments The Volkswagen Cyclist Section FROM the world- famous Terry factory come steel clips, bronze clips, stainless clips, big clips, little clips, wide clips, narrow clips - in fact clips in every conceivable shape and size. Illustrated here are two of our stock St patterns, 8o and 8r, made in a range of sizes to grip from 4 in. to rin. Maybe a clip of special shape would be necessaryforthejob you have inmind. Well, we can help you because we make clips for hundreds of uses.We can make to print or specification,orour Research Departmentwill design for you. Our knowledge of clips has advanced side by side with our 91 years' spring -making experience.

Sole Makers : HERBERT TERRY & SONS LTD., REDDITCH LONDON MANCHESTER BIRMINGH.-L11

by TERRY%PRIMO

* and just a few special shapes 461<111110 we have made to order. klte.H_4_

I.C.4 March, 1947 NEWNES PRACTICAL MECHANICS 181

ieho (if111%)1111) 'ARRY 'AMMER t.011° and Kit have created new build- ing records- Drat' nows " Useus,"says 'Arry,"and electricians, plumbers, concreters and hundreds of others will whizz up this housing problem ! " a stage se sting of N+ BEN GRINDER a keen proposition him- self, can put an edge OIL anything in next to no time - " Go intoany QUEENIE toolroom and as likely as not-you'll see me - QUARTERMASTER sharp, sharpen, and sharp- (known to all rate -fixers as ening - Ithink there'd Blondie the Gold-digger)is be precious little exports tippedas Lord Portable's without use ' Secretary - " I can squeeze any rate till the pips squeak - straight drillingorcorner, I'mthefastest SANDY SANDER The present shortage of materials and parts makes it difficult drilling proposition in little old England the famous 8047 for us to supply all the models our customers would like to and no wonder I'm the handiest pick- andcleaninging; have. Remember that Bassett-Lowke scale models, famous up in any assembly shop " for " true-to-life' realism, are well worth waiting for.In the champion- meantime please write for our Catalogue " Gauge ' 0 ' Model smoothsoffthe BREEZY BLOWER rough stuff where - Railways " (G112), price Is. ever he goes - This catalogue presents to customers some of our models now proud of his 200 m.p.h. blast of air "Rust removing's available and others which will be in production as soon as that makes him the world's fastest nothing to me - circumstances permit. machinery cleaner - " Suck or blow, Wild-fiasli hates Sandy-always knocking WRITE ALSO FOR : that's me. 'ban -bees' off the cost in most garages " How to Build a Traction Engine," price 6d. from Land's End to John o' Groats " " Laying Permanent Way," price 6d. doublethelite " How to Build a Gauge ' O' Steam Mogul from a set of ofmotors, finished parts," price Is. dynamos, clean "The Model Railway Handbook,' Standard Edition, fully upholstery,dust ELECTRIC illustrated, price 5s., post 4d. shelves. A capital TOOLS Model Supplies (L112), price 6d. rtir saver I am." The range of WOW Portable Electric Tools includes-Drills, Bench, Pedestal, Hand iSSETT-LOWKE LTD., and Flexible Shaft Grinders, Hammer and Hammer Kits, Screwdrivers, Chisel NORTHAMPTON Mortisers, Sanders. Blowers, Engine Reconditioning Equipment including Valve LONDON :112, High Holborn, W.C.I. MANCHESTER :28, Corporation St. Seat Servicing Kit. Engine Kit, etc. S. WOLF & CO LTD., PIONEER WORKS. HANGER LANE, LONDON, W 5 8180 THE "FLUXITE GUINS" AT WORK S. TYZACK & SON LTD. " She's a peach !cried 01 with delight, " Now I've soldered her up with "TOOLS FOR ALL TRADES" FLUXITE. Gosh !See her swerve. THE "ZYTO" Hey !She's shot off the curve. PROFILE OR JIGSAW MACHINE Look out in the kitchen !Hold tight.'' For SAWING and FILING OF

METALS (Ferrous and Non -Ferrous), PLASTICS AND WOOD. The Saw- For all SOLDERING work-you need FLUXITE-the paste flux ing and Filing of Metals. Plastics and -with which even dirty metals are soldered and " tinned." For Wood is an easy and speedy matter the jointing of lead-without solder ; and the " running " of white withthe" Zyto "ProfileorJig metal bearings-without " tinning " the bearing.It is suitable Saw Machine. Thereisno com- for ALL METALS-excepting ALUMINIUM-and can be used plicated mechanism orelaborate with safety on ELECTRICAL and other sensitive apparatus. control gear. Just flick over the ll'ith Floarite joiots can be "wiped- Switchandthemachine becomes your willingservant. Rugged successfullythattireimpossible construction, totally enclosed, by may other method powered by aZ H.P. Motor. The Used for over 30 years in Government works and by leading use of Double Cone Pulleys enables engineers and manufacturers.Of all Ironmongers-in tins, the machine to be run at either 280 10d., 1/6 and 3/-.Ask to see the FLUXITE POCKET BLOW or 500 strokes per minute simply LAMP, price 2/6d. by changing over the belt.Work Ak TO CYCLISTS! Your wheels will Table is9in.square andmaybe IF NOT keep round and true unless the tiltedin either direction, while the spokes are tied with fine wire at the crossings 7Z in. capacity of the Bow enables the DATA AT A GLANCE handling ofwork notnormally AND SOLDERED.This makes a much Stroke, 2/, in. accommodated on a machine of this stronger wheel.It's simple-with FLUXITE Saw Blade length, 6in. Throat capacity, 7Zin. size. -but IMPORTANT. Table measures 9in. x 9in. ALL MECHANICS WILL Speeds, 280-500 r.p.m. PRICE THE " FLUXITE " HAVE Motor, h.p. GUN puts "FLUX- Overall length, 16in. Single Phase £38 10s. Od. ITE " where you Overall depth, 10in. Three Phase £39 10s. Od, want it by a simple Overall height, 20in. pressure. Net weight, 78 lbs. £39 10s. 0d, Price 116 or filled FLUXITE FULL DETAILS ON APPLICATION 216. IT SIMPLIFIES ALL SOLDERING Write for Book onthe ART OF SOFT- SOLDERING and for LeafletsOn S. TYZACK & SON LTD. CASE -HARDENING STEEL and TEMPERING TOOLS with FLUXITE. Also on WIPED JOINTS."Price Id. Each. 341-345, OLD STREET, LONDON, E.C.1 FLUXITE LTD., Dept. P.M., Bermondsey Street,S.E.I Telephone : CLERKENWELL 4004-5-6 182 NEWNES PRACTICAL MECHANICS March, 1947 Join the Well -paid Ranks of the WS.- HOOK HYDROFIN TRAINED MEN THERE IS ALWAYS A GOOD POSITION FOR THE MAN WITH A SPECIALIZED TRAINING,BUT THERE'S NO WORTH -WHILE PLACE FOR THE UNTRAINED Ambitious men everywhere have succeeded through I.C.S. Home -Study Courses. So also can you. We JUST OUT I offer you the benefit of our 55 years' matchless ex- The new electric -driven " Sea Sparks."This is the perienceasthecreativepioneersof first kit for a hydrofoil boat ever to be produced, and it postal instruction.Since our establish- marks a new era in the model world. mentin 1891,more than1,000,000 British men and women have enrolled Hydrofin Handbook ... 2s. 6d. HNMII6 (1110th scale of HNi4), Drawings ... for I.C.S. Courses. I5s. Od. " Sea Sparks," Drawings ..5s. Od. " Sea Sparks," Drawings and Kit 35s. Oc'. The man with an I.C.S. Training in any one of the subjects listedbelow knowsitthoroughly, completely,practically. Electric Motor (suitable for either model) ... 25s. Od. And he knows how to applyitinhis everyday work. " Sea Bug " Junior Model Kit and Drawings ...7s. 6d.

Accountancy Concrete Engineering Mine Surveying Advertising Cotton Manufacturing Mining Electrical HYDROFIN" Aeronautical Engineering Diesel Engines Motor Engineering Aero Engine Fitting Draughtsmanship Motor Mechanic EGYPTHILL, COWES,ISLE OF WIGHT Aero Fitting (State which branch) Motor Vehicle Elec. Aeroplane Designing Drawing Office Practice Municipal Eng. Air Brakes Electrical Engineering Plastics Air -Conditioning Electric Power, Lighting, Plumbing Aircraft Eng. Licence Transmission, Traction Quantity Surveying Architecture Eng. Shop Practice Radio Engineering Architectural Drawing Fire Engineering Radio Service Eng. Boilermaking Free- Lance Journalism Refrigeration Book-keeping Fuel Technology Building Construction Heating and Ventilation Sales Management Every home should have Building Specifications Hydraulic Engineering Salesmanship Business Training Hydro -Electric Sanitary & Domestic Eng. Business Management Illumination Eng. Sheet -Metal Work Carpentry Industrial Management Steam Engineering Chemical Engineering Internal Comb. Enn. Structural Steelwork a"Cr ystal " Chemistry, Inorganic and Joinery Surveying Organic Letterer (State which branch) Civil Engineering Machine Designing Telegraph Engineering No matter what the job-interior Clerk of Works Machine -Tool Work Textile Designing or exterior painting, distempering, 75,_ Colliery Examiner's Marine Engineers Welding, Gas & Elec. Colliery Overman's Mechanical Drawing Woodworking Drawing or re-cellulosing a car, the " Crystal " Commercial Art Mechanical Engineering Works Engineering Spray Gun will enable you to do it complete And most of the Technical,Professional, and Matric Exams. Special Hoover to perfection. connectar 3:6 extra If you needtechnicaltraining,our advice on any matter concerning Connected to any standard vacuum your work and yourcareer isyoursforthe asking-free and without cleaner, the " Crystal " will handle obligation.Let us send you full information regarding the subject in which you any normal finish without mess or are specially interested.DON'T DELAY. Make ACTION your watchword. waste and without fatigue to the operator.It does not require expert The successful man DOES to -day what the failure handling and being precision built of INTENDS doing to -morrow. Write to us TO -DAY first class materials it will give long, trouble free service, and saveits Use this Coupon cost over and over again. The " Crystal " Spray Gun will be INTERNATIONAL CORRESPONDENCE SCHOOLS LTD. forwardedbyreturn,postfree, on Dept. 95, International Buildings, Kingsway, London, W.C.2 receipt of remittance with order. Please send me particulars of your courses in We are Retail Distributors of Pinchin's Paints and can supply from stock ceiling Name Ago *I ARE EXRISITIRC AT ENE (USE BLOCK LETTERS) white and most shades of their interior Paints and Distempers.Particulars on Address application. Addresses for Overseas Readers

Australia :140, Elizabeth Street, Sydney. O Egypt :40, Sharia Malika Farida, Cairo. DOMESTIC SUPPLY CO. Oil 3

India : Lakshmi Bidgs., Sir Pherozsha Mehta Rd., Fort, DAILY MAIL Bombay. 341, REGENT'S PARK ROAD, New Zealand : 182,Wakefield Street, Wellington. LONDON, N.3 IDEAL HOME Palestine : 33, MamillahRd.,Jerusalem. ICS exhibition (Near Finchiey Central Station) Tel.: FINchley 5193 South Africa :45, Shortmarket Street, Cape Town. OLYMPIA MARCH 4-29 March, 1947 NEWNES PRACTICAL MECHANICS 183

HURRY/ HURRY/ I/00X/ Each 15/- National Savings Certificate bought now - and, of course, held - becomes 20:6 in 10 years' time. This interest is free of income tax. But to get this high rate of interest you must buy before April 1st, Don't delay. Every person may hold up to 500 Certificates. 01117641g I.,sued by The Naticoml $atiilys Conentitlet He relies on a skilled ground crew for the smooth working of every single part of his aircraft. If you are an ex -airman with 2 years' war experience and Leytools still under 42, you can rejoin the R.A.F. for are 4 years' service under the attractive new Bounty Scheme. You keep your old rank.You enjoy QUALITY Tools improved peace -time conditions.You earn in- PRECISION HAND DRILLS creased pay plus a further £125 - free of tax. As illustrated.I -inch dia- Thousands are rejoining. Come back with them. meter capacity. Send the coupon now. RATCHET SPANNERS 42Stocksizes. Indis- pensable for assembly and MEN IN CIVIL LIFE servicing work. SPECIAL : MOTORISTS' between 171 and 33 may enter on: of SETS of Ratchet Spanners 100 trades for 5 or .to years. complete in wallet. UNIVERSALLY JOINTED SOCKET SPANNERS 58 Stock sizes. I am interested in *joining, rejoining the (*Strike out word which does not apply) POCKET SCREWDRIVERS 4 -bladed. " Lcytools " are obtainable Royal Air Force PRECISION fromallgood Toolshops, Ironmongers and Stores.If any difficultyinobtaining Please send details without obligation. H AND locally,sendyourorder direct, or write for descriptive D RILL leaflets giving full details of Name No sizes and prices of any of Prov. Patent No. the above tools. 20987,44 Address

Every "Leytool"is FURTHER "LEYTOOLS " ARE Post to a genuinepost-war NOW BEING DEVELOPED Air Ministry, Dept. I.R., design.asaccepted Victory House, bytheCouncilof Industrial Design for LEYTONSTONE JIG & TOOL CO., LTD., Kingsway, display at the LEYTOOL WORKS, HIGH ROAD, LEYTON, LONDON, E.10 London, W.C.2 x2EN1 "Britain Can Make Telephone: Leytonstone 5022-3 It" Exhibition. 184 NEWNES PRACTICAL MECHANICS March, 1947 MY VON 11fi LATEST DESIGN HEAVY DUTY BENCH LATHE (Illustrated on Cabinet Stand) 3?in. (10in. Swing in Gap) Type ML.7. To be shown at the BRITISH INDUSTRIES FAIR Castle Bromwich-May 5th to 16th. STAND No. D. 112. Manufacturers of Engineering Section. DRAWING and SURVEYING INSTRUMENTS

SLIDE RULES

DRAWING MATERIALS

DRAWING OFFICE STATIONERY A. Q, TI -1 0 R.N TO N LTD 41 GAR.TIIDE IT. MANCt4EITER 3. MYFORD ENGINEERING COMPANY LIMITED

BEESTON NOTTINGHAM 'Phone: 54222 (3lines)

MAKE THESE YOURSELF AND MAKE ---,-5

MONEY! -:'?i - ' Withourtoy -castingiimuldsand Toy Soldiers, fast -drying enamels, making these and Cowboys & Indians, Wild ?..? Farmyard other models becomes a really profitable Animals, pastime, or fascinating hobby.Full in - Aeroplanes, structions with every first order.Send ' Ships, Cars, etc. s.a.e. for full details. Write to -day ! PROGRESS TOY CO.LTD. Dept. P.M., KIRBY ROAD, BLACKPOOL, S.S. Telephone : BLACKPOOL 750 testseverythingelectrical RADIO, HOUSEHOLD APPLIANCES AND MOTOR CAR LIGHTING Fibrax) ETC. Ask your local Factor to and get there safely! show you one of these In any emergency Fibrax Brake Blocks will always in- pull you up.They are made of material specially remarkable processed togivethe maximum braking efficiency. Highly resistant to wear. Production limited in these strumentsand days, but you can depend on your dealer to do his to putyour best to supply you. name down on FIBRAX LTD., his waiting list. 2 TUDOR STREET, LONDON, E.C.4. March, 19 47 NEWNES PRACTICAL MECHANICS 185 A Fine iehierement! in Radio Reception has been attained by the latest S.G. BROWN, pc K MOVING COIL HEADPHONES

Where High Fidelity Reproduction is required,such as forDX work, Monitoring and Laboratory purposes etc., these precision -built Moving Coil Headphones will be highly appreciated.

Technical Details t D. C. RESISTANCE - 94 ohms per pair IMPEDANCE - Type K. 104 ohms Cr 1,000 c.p.s. SENSITIVITY - 8Dbs. above I microwatt per bar C 1,000 c.p.s. If you would like details of all the types of S. G. Brown PRICE 5 0 PER PAIR SPECIAL Headphones,sendfor HANDY CARTON illustrated Brochure "P.M." Descriptive Brochure "P.M.K." willbesentfreecnrequest.

Telephone : A7Ti- ACOrn 5021 rt VICTORIA ROAD, NORTH ACTON, LONDON, W.3

MULTICORE SOLDERS LTDMELLIER HOUSE. ALBEMARLE STREET LONDON The way to success

TRACE MARK Sia/eYEGO. THERMAL with snapshots DELAY SWITCHES this spring ?Jeni4 Use only those chemicals upon which you can rely. r,lectclio e:7nte1eliont Follow the instructions given by the makers and, 4 VOLT 5 VOLT 63VOLTHEATERS if your exposures are correct, you will get perfect results.

gelepb 0,2r. WOOLWICH 1422 AZOL for the negatives CAMBRIDGE ROW WOOLWICH SE 18 A concentrated one -solution developer.All you have to do is to add water. With each bottle comes a simple set of Time and Temperature tables for developing plates or filmsin Shows the way to TECHNOlOGICA1 SUCCESS tanks by daylight, or in dishes ina dark room. IN ENGINEERING BRANCHES AND PROFESSIONS UNIVERSAL forthe prints Throughout industry inevery country, but particularly in Great Britain. Universal is a concentrated M -Q developer which only needs technologicalsuccess has become the the addition of water. Used for Gaslight or Bromide prints basis requiredforpersonal success. Write nowforthisgreatguideto itwill give you sparkling results.Contains the chemicals careers in Engineering covering -142, for brightening prints, and 326, for even flow. Mechanical,Electrical, Chemical, Production, Aeronautical, Auto- SEND 3d. IN STAMPS AND WE WILL POST TO YOU A COPY OF mobile, etc.. and which shows how to become A.M.I.Mech.E., A.M.I.E.E., THE NEW 38 PAGE BOOK CALLED " HOME PHOTOGRAPHY." A.M.Inst.C.E.,A.M.I.Chem.E., etc., WE WILL ALSO ENCLOSE A SET OF THE AZOL TIME AND in which and other engineering institution TEMPERATURE TABLES AND AN ILLUSTRATED CATALOGUE examinations T.I.G.B. home -study students havegained OVER FIFTY OF OUR CHEMICALS. MARK YOUR ENVELOPE DEPT. 41. FIRST PLACES, to- Ask your dealer for Scales Brand Chemicals The Professional Engineering Tutors, JOHNSON & SONS MANUFACTURING CHEMISTS THE TECHNOLOGICAL INSTITUTE LTD., HENDON, N.W.4. Established 1743 OF GREAT BRITAIN, 213, Temple BarHouse.London,E.C.4. 186 NEWNES PRACTICAL MECHANICS March, 1947

PREPARE FOR COMPETITION -NOW! As the Engineering Industry swings into its peace -time stride, the inevitable competition for the secure and well -paid posts will return.Itis the man who stands out from the rest because he is technicallytrained who will be in the happy position of taking over the more responsible, more secure, and better paidpositions. " ENGINEERING OPPORTUNITIES " will show you how to get this all-important technical training quickly and easily in your spare time.This 100 -page book is full of valuable information and explains the simplest way of preparing for recognised Examinations. Among the courses described are : MECHANICAL ENGINEERING GROUP ELECTRICAL ENGINEERING GROUP A.M.1.Mech.E. Estimating A.M.I.E.E. Electricity Supply City & Guilds Foremanship City & Guilds Electrical Meters General Mechanical Eng. lig & Tool Design General Electrical Eng. Electrical Design Diesel Engines Viewing & Inspection Alternating Currents Illumination Draughtsmanship & Tracing Welding Power House Design Installations Works Management Sheet Metal Work Traction Telegraphy Press Tool Work Maintenance Eng. Mains Eng. Telephony Pattern Making Metallurgy Foundry Practice Refrigeration WIRELESS GROUP A.M.Brit.I.R.E. Advanced Wireless COMMERCIAL ENGINEERING GROUP City & Guilds Radio Servicing A.M.1 P.E. Cost Accpunts General Wireless Television Commercial Eng. Languages Short -Wave Wireless Talking -Picture Eng. CIVIL ENGINEERING GROUP AUTOMOBILE ENGINEERING GROUP Road Eng. A.M.I.A.E. General Automobile Eng. A.M.I.C.E. M.I.M.T. Garage Management Inst. Mun. & Cy. Engineer Hydraulics City & Guilds Electrical Equipment A.M.I.St ruct.E. Municipal Eng. I.A.E. Repair Certificates High Speed Diesels M.R.San.l. General Civil Eng. Sanitary Inspector Structural Eng. Specifications Reinforced Concrete AERONAUTICAL ENGINEERING GROUP Structural Design Railway Eng. A.F.R.Ae.S. Aero Engines R.A.F. (Maths.) Navigators' Licence SURVEYING AND BUILDING GROUP Pilots' Licences Aeroplane Design Ground Licence Meteorology A.R.I.B.A. Costing & Valuations F.S.I. Heating & Ventilating A.M.I.H. & V.E. Clerk of Works UNIVERSITY DEGREES L.I.O.B. Surveying & Levelling London Matriculation University Entrance F.A.I. Building (all branches) School Certificate Intermediate B.Sc. WE DEFINITELY GUARANTEE " NO PASS -NO FEE " If youareearningless than flOa week you cannot affordtomissreading " ENGINEERING OPPORTUNITIES " ;ittells you everything you want to know to make your future secure, and describes many chances you are now missing.In your own interest we advise you to write for your copy of this enlightening guide to well -paid posts NOW-FREE and without obligation. BRITISH INSTITUTE OF ENGINEERING TECHNOLOGY 410A, SHAKESPEARE HOUSE,17, STRATFORD PLACE, LONDON, W.1 THE B.I.E.T. IS THE LEADING INSTITUTE OF ITS KIND IN THE WORLD March, 1947 NEWNES PRACTICAL. MECHANICS 187

SUBSCRIPTION RATES (including postage)

Inland -. 10s. 6d. per annum.

Abroad - 9 10s. per annum. PRACTICAL Canada - .. lOsper annum. Editorial and Advertisement Office :" Practical Mechanics," Geiarge Newnes, Ltd. Tower House, Southampton Street, Strand, W.C.2 'Phone : Temple Bar 4363 Telegrams :Newnes, Rand, London. MECHANICS Registeredatthe G.P.O. for transmission by Canadian Magazine Post. Owing to the paper shortage "The Cyclist," "Practical Motorist," and "Home Movies"are Copyright in all drawings, photographs and articles temporarily incorporated. published in " Practical Mechanics " is specially reserved throughout the countries signatory to the Editor: F.J. CAMM Berne Convention and the U.S.A. Reproductions orimitationsof any of thesearetherefore expressly forbidden. VOL. XIV MARCH, 1947 No. 162 FAIR COMMENT BY THE EDITOR The Engineering Advisory Council

THEMinisterof Supply recentlyInternational Management Conference industrial consultants for those who will make announcedthe appointment of an THE EighthInternational Managementa considerable profit from the advice. Engineering Advisory Council to pro- Conference is to be held in StockholmBritain Can Make It Exhibition vide a means of consultation with employersthis year from July 3rd to July 8th, under THE Government sponsored " Britain Can and workers in the industry on matters oftheauspicesofInternationalScientific Make It " Exhibition, did not run at a general concern.Matters normally handledManagement. Previous Congresses took placeprofit.In the 14 weeks 'of its life 1,432,369 by the Joint Organisation of Employers andin Washington in 1938 ; in London in 1935 peoplevisitedtheexhibition,andthis Trade Unions in connection with wages andand on five preceding occasions. represented a loss of 3s. per visitor. We did conditions of employment are excluded. New management experience and morenot think that the exhibition was particularly The Engineering Industries for this purposewidespread applications of established prin-brilliant as representing a true cross-section will comprise mechanical, electrical and radiociples come fast in wartime, and the Congressof British industry. There were far too many engineering, but not shipbuilding or the ironwill provide the first post-war opportunitynebulous ideas, such as the absurd bicycle and steel industries, which fall within thefor many people in this country to secure aof the future, which we venture to suggest purview of the Iron and Steel Board. swift appraisal of the principal trends andwill never be made, and the claims for which The Council will consist of equal numbersmanagements abroad since 1939. could not be justified. of Trade Union and Employer members with The three plenary sessions of the Congress We think the Selection Committees were the Minister as chairman. will be devoted to the philosophy and applica-in error in permitting publicity stunts of It is hoped that the Council will providetion of Scientific Management, the regionalthis sort, for it might give the impression local planninginmodernsociety,andabroad that Britain Can Fake It, as well as regular machinery for consultation with aindustrial relations and the responsibilities of widecross-sectionof theleadersof the make it. Evidently Britain can lose it, if it cost Management and Labour. the country about £250,000.The exhibition engineering industry on both sides ;those We are astonished that so much attention who canspeakwith authority and who was organised by the Council of Industrial between them represent the views of at leastis being devoted to these altruistic things atDesign, but we do not think that they can a time when the world requires output oftake credit to themselves for anything beyond the main groups. raw materials. Far too much attention is There will naturally be speculation as to stagingapublicentertainment. Things being devoted to welfare schemes, shorterwere exhibited which should not have been the subjects which this new body will discuss.working weeks, music while you work, social There will certainly be no lack of material. exhibited and important articles were not clubs, and converting work into play.Whatexhibited which should have been shown to One subject of great concern to the engineeringwe require are some Congresses to increase is shortages of certain raw the world. industry the output, for without output there will be no We think that such exhibitions in future materialssuchassteel. Employers andwork.All money comes from industry, and workers are very concerned as to how supplies should be staged by those with long experience without industry there will be no money andin the planning of exhibitions and with run- areallotted. The Council willserveas no revenue with which to pay for thesening them at a profit. a two-way channel for the exchange of viewsgrandiose schemes for a modern Utopia. Anyone can run an and of information between the Government exhibition at a loss. It must have been particularly aggravating to the British public to and industry, and it is hoped that it will leadElectrical Queries to a clearer appreciation by the Government view British -made goods which they could oftheirrespective AGAIN itis necessary for us to remindnot buy in this country but which are being andoftheindustry readers that we have suspended oursupplied to liberated countries coupon -free. problems. electrical query service.Readers continue Itisdifficult to see, however, what thisto send in questions relating to the rewiringRadio Controlled Models Society new Council will perform which could notor the conversion of dynamos, and because ON December21St,1946, a meeting of be even more satisfactorily performed byof staff shortage we are unable to deal with persons interested in the radio control existing organisations.If the Governmentthese for the present. of models was held in the Y.M.C.A., Man- wishes to know anything about industry it Similarly, we do not undertake to reply tochester. This was the first meeting of its has the Trade Unions, the Masters Federa-questions relating to explosives, nor to under-kind to be held on this subject and it was tions, the learned societies, the Joint Produc-take chemical analyses. Nor do we undertakecalled for the purpose of arranging closer co- tion Committees, and it has also that valuableto give details concerning commercial products.operation between radio control enthusiasts. source of information, the technical press,In most cases licences are required which are Interested enthusiasts from various parts which fairly reflects the views of all sides of aonly granted to recognised manufacturers, orof the country, representing all parts of the problem. else they are quite unsuitable for productionmodel movement, were present.It was event- In a multitude of counsellors there is notin a small way.Also we do not undertakeually decided that a permanent body be set up necessarily wisdom, for too many cooks spoiltodesignspecialapparatusforreaders.for the discussion, guidance and development the broth !We cannot see that any usefulOne reader wrote saying that he had accepted aof the radio control of models.This body purpose is served, especially in these days ofcontract to make 20,000 of a particular article.will in future be known as the Radio Con- labour shortage, by this duplication of effort.Would we please design the press tools fortrolled Models Society and forthe time The Governmentissurelysufficientlyhim and tell him what plant he would require ?being meetingswill be held monthly in advised by its own permanent civil servants.These are questions which should be addressedManchester. We are, therefore, not hopeful that this newto a consulting engineer. Our Query Service Acting Secretary of the society, Mr. R. Council will perform useful work nor functionis open within the above limits to any readerLawton,so,DaltonAvenue,Whitefield, as it was designed to do. in his private capacity.We do not act asnear Manchester. 188 NEWNES PRACTICAL MECHANICS March, 1947 Armature Winding Practical Notes Dealing With Armatures Suitable for Fractional Horse -power Motors By A. H. AVERY, A.M.I.E.E. (Reprinted at the request of many readers from an issue now out of print.) AS many readers may have discoveredbunsen burner until it is just reddened ; thecoil should span.The answer to the first for themselves, there are a numbercovering usually then rubsoffwith veryquestion is determined by reference to the of pitfalls lying in wait for those whoslight friction. commutator.Every armature must have the attempt the repair and rewinding of small same number of armature coils as there are armatures for the first time.First there isBurnt -out Coil bars in the commutator.Even when there the specification itself to consider, that -is, To discriminatebetweenthedifferent isa discrepancy between the number of the number of turns to give to each coil armature slots and the number of commu- and the correct gauge of wire ; then comes tator bars this rule still holds good, as such the matter of insulation, the actual manipula- conditions are met by " grouping " two or tion of the coils, the number of slots they more coils in each slot instead of one.It should span, and, lastly, what pitch to be is quite a common thing to find a 24 -part given when connecting them uptothe commutator, for instance, on an armature commutator. having only 12 slots in the core, in which It is necessary in the present instance to case 24 coils would be wound off and two limit the discussion to such sizes of armature put intoeachslotinsteadofonlyone. as would be employed for " fractional horse- Similarly a 16 -part core and 48 -part com- power " machines, since the procedure for mutator would have its48 coils grouped dealing with larger armatures wound with three per slot, and so on.Nearly all arma- copper strip or bar instead of small wire Start Finish S F turesare" former -wound," by whichis of circular section is generally along totally meant that the coils areall wound on a different lines of treatment, and outside the LoopP separate " former " or wood block of suit- scope of the small winding shop. tand 2. - One- and two -coil -per -slotable shape and all to the same size.The grouping. ends are then taped up and the coils packed into the armature slots separately afterwards, Winding Specification kinds of insulating covering is also not tooinstead of being wound on direct in position Concerning the winding specification itself, easyon acoilthat has been burnt.Itone at a time.Itis only in cases where this belongs to the province of design rathermay be generally taken, however, that plainheavy gauges of wire are called for, such than of repair, and for that reason one mustenamel coverings are employed on wiresas are associated with very low voltages, that assume itto be already known ;there arefiner than No. 4o s.w.g. ; enamel and single many handbooks dealing with this aspect silkordoublesilkcoverings on gauges of the subject to which the reader can referbetween No. 32 and 38 s.w.g. ; and double ifinterested.Where repairs and rewindscotton coverings, 6 mils thick, for wires of are in hand, too, the specification is alreadyNo 24 to 3o s.w.g. Coarser gauges than No. 22 have generally thicker double cotton coverings ranging between to and 15 mils in thickness. The importance of choosing asuitable covering for the wires is not always fully appreciated. It greatly affects the " space Fig. 7.-The appearance of the formed coil. factor " of the windings and often makes all the difference between an easy winding and one that is impossibly tight in the slots. For instance, an armature slot having a winding space equivalent to sq. in. would accommodate a maximum of t,tto turns of No.33s.w.g.wirecoveredwith 6 -mil cotton ;but bytheuseof doublesilk covering instead 1,600 turns of the same gauge would go into the same space, while Fig. 6.-A suitable former for small armatures.no fewer than 1,975 turns of the wire could be accommodated if the covering were ofFig. 8.-An armature with semi -enclosed slots. enamel only.Tables giving the number of available from an examination and count ofturns per square inch for various gauges the turns and gauge of wire already existingof wire and for various coverings can alwaysthe wire is hand -wound direct into the slots on the damaged armature, ifitis not toobe consulted when there is any difficultyof the core.The great advantage of former Generally it is possible winding is that not only can the fine wire badly burned out. with " tight " windings. coils be run offata comparatively high to lift one complete coil out of the armature speed in the winding machine, but that each slots, and either unwind it carefully, count-Turns Per Coil coil can now be separately insulated before ing the turns, or,ifthis cannot be done The numberofturnspercoilbeingassembly, giving invaluable protection thus owing to its condition, the coil can be cutknown, together with the gauge of wire andto the most vulnerable points.Also since across the end winding, the individual wiresnature of its insulating covering, the nextthe coils are all of the same shape and length then being spread out and counted. thingistodecide how many coilsare their individual weights and resistances are Admittedly this may prove tedious 'work required, also how many armature slots eachidentical, the winding becomes symmetrical if the gauge of wire is very fine, but it forms a much more definite guide to a correct rewind than merely making a rough estimate Pole Pitch Pole and guessing at the turns and gauge.In Pitch particular itis necessary to be careful in .." 180 s 90°' measuring up the gauge.A short length, of wire should be extracted from an old coil andthecoveringremovedbycarefully passing it through a piece of folded glass- N paper of finest grade until the bare metal shows. Stretchingmustberigorously avoided, nor isit the slightest use to gauge Figs. 4 and 5.-(Above) over the old covering.When the wire is Fig. 3.-Three-coil- A two -pole field magnet. very fine the safest way is to pass a length per-slot grouping. (Right) A four -pole field of it through the flame of a spirit lamp or magnet. March, 1947 NEWNES PRACTICAL MECHANICS 189 Coils fBinding Band makes the coils easier to assemble, especiallythat they pack together symmetrically.The in two -pole windings, as they do not thenappearance of the formed coil when shaped bunch up so much at the ends, while elec- thus will be seen from Fig. 7. trically they are almost identical in effect. Armature coils are not generally taped all the way round but at the ends only, in order Armature Slots to keep them in shape during assembly.It When the number of armature slots is notalso assists by providing extra insulation in exactly divisible by two or four, the practicethose parts of the winding which are at the is to make the coil span the nearest smallergreatest potential difference.In open -slot whole number.A 13 -slotarmature,for al matures the coilissometimes tapedall instance, running in two -pole fields, obvi- over, but with semi -enclosed slots end taping ously, could not have a coil span of 1 to 71only is possible, since in order to insert the (=I8o degrees) and would therefore besides of the coils in the narrow slot openings given a span of i to 7. the wires have to be separated and fed in After settling the number of turns, thea few at a time, which is impossible when gauge of wire, and the span of the coils,taped all round. comes the question of a suitable former for winding them.For small armatures theseCoil Taping Figs. 9 and to.-(Above) An armature withare generally lozenge shaped and built up Although coil taping serves a very useful 'pen type slots.(Right) Windings forming aon the lines shown in Fig. 6.The centrepurpose in separating parts liable to insula- continuous succession of loops. block A is of hard wood or fibre, of a thick-tion breakdown, neither the taping nor the ness slightly less than the width of the arma-wire coverings by themselves can be relied ture slots.Two separate flanges larger inupon to provide sufficient protection between and better balanced for running at highall ways than the centre block by the radialthe live wire and the iron of the core, with- speeds,andthereisconsequentlyless depth of the coils are then made up, B beingout furtherprecautions. Slotliningsof tendency towards sparking at the brushes.permanently fixed to A, and C made detach-presspahn, leatheroid, or empire cloth are With hand windings there is often a con-able by means of a couple of wood screws.always necessary beforefinal assembly of siderable difference between lengths, weightsSawcuts are made where shown at D, thethe coils, the thickness of these slot linings and resistances of the first and last coil put'purpose of which is to enable thread to be depending upon the voltage to which the on the core, which leads to vibration troublespassed through from side to side underneath windings will be subjected.One layer of and bad commutation.Moreover, shouldthe coils after they are wound on each ofleatheroid to mils thick is sufficient for the theinsulationgive way thefaultnearly the four short ends, tying this firmlyto slot linings of most small armatures working always happens in one of the earlier coils prevent the coil from collapsing when taken up to 250 volts, or two thicknesses for 500 to be put on, making it necessary to unwindoff the former.The two sides L and S ofvolts, but if these have to withstand a flash the greater part of the armature to rectifythe centre block determine the length of thetest they should be reinforced by a further it.But in the case of former windings oneactive part of the coil which lies in the slots. thickness of to -mil empire cloth. The more side of the coils can be lifted out of the S is made about tlin. longer than the actualinsulation there is in the slots the less will slots and the defective coil removed bodily be the room for actual wire, so that one without destroying the others. Back End Commutator is obliged to keep a close watch on this Bars ConnectionS 411° point and provide only the minimum thick- Former Winding ness ofinsulation compatible with safety If it were necessary to still further stress from breakdown, otherwise the quantity of the advantages of former winding it is that eCilAt active wire, and consequently the final output the method lends itself particularly well to obtainablefromanyarmature,willbe grouping two or three coils per slot and seriously restricted. saving considerable trouble with their inter- attt40 When an armature core has semi -enclosed connections.For example, the typical shape slots as in Fig. 8 the coils are secured from of any former -wound coil is seen in Fig. I. flying out under centrifugal stresses by thick This is a single coil, but if they are to be °itaWr leatheroid strips inserted under the hook of grouped two per slot, instead of cutting the the teeth.If, however, the armature has wire when the required number of turns Fronf End \Coils In open -type slots as Fig. 9 the coils have to Connections Slots be held down by binding wire bands of have been wound for the first coil, a loop tinned copper wire sunkflushwiththe is taken out long enough to reach the com-Fig. 11.-A simplified diagram showing thesurface of the core, strips of leatheroid or mutator as at Fig.2,and the second coil method of winding an armature, mica being laid along each slot previously continued until complete.The interconnec- to protect the coils when the band is being tions between coil 1 and coil2are thuscore length, and L is longer than S by twice automatically made, and since the ends ofthe radial depth of the wound coil.One soldered up. the double coil can be taped up as thoughor two modifications will no doubt be found The actual interconnection from coil to necessary after trial to finally settle upon the coilofasmalllap -connectedarmature, it were one coil it becomes much easier to although apparently acomplicated matter, assembleinthearmatureslotsthanif best dimensions. isin reality simplicity itselfif the factis wound as two separate and independent The end windings make an angle of aboutborne in mind that the object in connecting coils, besides saving work in connecting up 90 degrees with one another, and 45 degrees up is only to join the end of one coil to later on. with the sides of the coil. the beginning of the next all the way round Similarly, if a three -coil -per -slot grouping the armature in regular sequence so were calledfor,as would be the caseifPreparing the Coils that the commutator had three times the number In preparing the coilsthe procedure isall the coils are in series with one another of bars as the armature core had slots, thefirst to wind off a complete set, tying them untilthe starting pointisreached again, winding would take the form shown in Fig. 3. at the corners temporarily.They are thenwhen the winding closes upon itself, making In these figures for sake of simplicity onlymade hot in the oven to dry out any moisturean endless circuit.Every junction formed one turn per coil has been indicated to avoidand immersed bodilyingoodinsulating ccaqusion.In practice there would gener-varnish such as " Armacell " untilallair ally be a large number of turns in each coilbubbles cease to escape. 'They are then between each starting and finishing point. drained off, again warmed until the varnish Of Before the former or shape can be madeis well set, but not baked out hard, as they up for winding the coils, itis necessary tomust remain flexible until placed in position Brushes decide what shallbetheirspaninthe in the slots.After taping the ends with armature slots.This is determined by thethinnest cotton tape each coil has its short numberofpolesinthefieldmagnet. side laid in one of the armature slots, and Theoretically the coil span should be thewhen the bottom halves ofallcoilsare same as the pole pitch, that is, the distance inserted the long sidesare brought down between the centre lines of Holes of opposite one by one into the top of the remaining Commutator polarity.In a two -pole field magnet, for slotspaces, giving them the correct span instance,the armaturecoilsshould spanat the same time.When the coils are of slotsdiametricallyopposite,thatis,18o fine wire and quite pliable no preliminary degrees apart, as Fig.4.And in a four -" forming " is necessary, but if they are stiff pole field magnet the span of the coils would they may need a twist given to the lozenge - be one -quarter of the circumference, or 90 shaped ends in order that the inner and degrees, Fig.5. Itisusual, however, toouter sides may pass one another more easilyFig.I2.-Asingle armaturecoil shown in shorten the span by about one slot, as thisin crossing at the ends of the armature, so position. 190 NEWNES PRACTICAL MECHANICS March, 1947 where one coil meets the next is made aend connections by the curved lines linkingThis is the neutral position in which little connection to one commutator bar.Thetogether the active wires. or no E.M.F. is generated in the coils and choice as to which one will be explained is the best position for the current flowing later, but in effect the windings form a con- The last remaining point that has to beround them to becommuted " or changed tinuous succession of loops as indicated bysettled when connecting up the armaturein its direction.Consequently the starting the diagraminFig.to. This diagramcoils to the commutator is what pitch,if and finishing ends ofthiscoil must be shows only six coils, but is typical of theany, to give to the junctions between coilsbrought down to those two adjacent commu- method whatever the actual number of coils before soldering them tothe commutator tatorbars which lieon eitherside of a may be. bars.This is very important, because no centrelinedrawn throughthebrushes, armature, even if its coils are correctly inter-wherever they may happen to be situated. connected and otherwise free from faultsSometimes the brush line coincides with the Armature Connections can work properly unless connected to thecentres of the field magnet poles, more often Armature connection diagrams are apt tocommutator with the proper relation betweenit lies at right angles to the poles, since this look complicated even when one turn onlypole centre'sand brush centreline. In leaves more room forthe brush holders per coilis shown, and the least confusingother words, the act of commutation mustbetween the fieldcoils.Occasionally they way of showing these is represented by thebe arranged to take place while the coil isare placed at some intermediate angle for "radial" diagram, such as Fig. tt.How-in its, " neutral" position.This may best structuralreasons,but no matter where ever many turns per coil there may be, itbe explained by inspecting the accompany- they may be itis always essential that the is only the start and finish that matter foring Fig.12. Here a single armature coilarmature -to -commutator connections should connecting purposes.In this figure the twoAB is shown in aposition such thatits be planned out so that they follow the brush active sides of the coil are represented bysides are " sliding " momentarily along thecentre line position, when the coil itselfis the radial lines, the commutator bars by thelines of force which proceed from the magnet in its neutral position in relation to the field central segments, and the front and backpoles N and S instead of " cutting " them. magnet poles. London's Largest Electricity Plant Where a LargePart of London'sElectricityis Generated

VER Y topical, in view of the Fuel Minister's recent warning to the public, are these photographs recently taken at Fulham Power Station, largest electricity generating plant in London, and the largest municipal undertaking of its kind in the whole country. It produces 61 million units per day from five 50,000 kW turbo -generators, and consumes several hundred tons of coal per day. When it is necessary to " shed the load," it is from this station that a large part of London's electricity supply isreduced, or cut off. Workinginconnection withthepower station is a well-equipped laboratory for the control and testing of water, coal, lubricating and insulating oils, etc., and the investigation of all chemical problems associated with power station operation.

(Above) A corner in the Fulham Power Station showing the feed pumps which supply water to the boilers at the rate of 6,30o gallons per hour per pump. (Right) One of the five switchhouses for operating the network of the S.E. grid.The Metropolitan -Vickers 66,000 -volt switches, or oil current breakers, have a rupturing capacity of millionkilo -volt -amps. Each switch weighs zo tons, including 31- tons of oil. March, 1947 NEWNES PRACTICAL MECHANICS 191 A Turret foraSmall Lathe Constructional Details of a Useful Accessory for the Home Mechanic By W. BADDELEY DURING the war Ihad occasionto The arrangement of produceaconsiderable number ofthe locating plunger, small turned parts on my 3in. lathe,part (D), is aLo show n and decided it would be worth while to make in Fig. 2. The a simple turret for slide rest fixing beforevarious partsare commencing the work.This turret provedturned from M.S. bar, to be very satisfactory, and I give the follow-the plunger beinga ing details ofitsconstruction, which maysliding fit in the hole. be of use to other readers. The plunger and rod Fig.t shows the complete turret, and inare turned from the Fig.2 the details of each pail are given.solid and the knurled As shown in Fig. 2, part (A) is the rotatingtop is screwed on. toolholder, and is drilled to take six tools Thecorrecttaper Fig. 1.The turret mounted on the cross -slid: of a lathe. made from 5/I6in. diarn. steel rod.They of the locating holes Small flutes can then be cut on the tapered end and the tool suitably hardened and used To SuitLgthe in the same manner as a tapered reamer.It is advisable at this stage to turn the plunger, using the same top slide setting to turn the taper.This ensuresthat both tapers are IN V, int alike. a The reamertoolisusedthroughthe 1111\ \ plunger hole in part (A) to widen out the 7,12.0ie six locating holes in part (B), and the parts (A), (B) and (C) should be assembled for this To Suit operation. Lathe Holes for Cutting Tools The locating plunger can now be fitted, and the job is now complete except for the holes in part (A) to receive the cutting tools. To drillthese the turretisbolted on to the slide rest and a 5/16in. diam hole drilled in part (A) for each position of the plunger. 2,,-,P C. !I*t Ir now remains to drill and tp the six [gutting Holes holes for the tool clamping bolts in part (A). This particular turret was designed to bolt on toaslide rest provided withatable which has slots for fixing bolts.It should be stated, of course, that to fix the turret 2' PC in position the top slide has to be removed. Set pun Holes If the reader's lathe does not possess these slotsan alternative method of fixingwill Fig. 2. Details of the component parts for a small turret. easily be found. The photograph (Fig r) shows the turret are held in position by six lin. Whit. bolts.is obtained by the use of a simply made tool.in position on the lathe.It will be noted This part can also be made to take fourItis made from a piece of 5/16in. diam.that the fixing bolts are of various types, this tools,in which casethere must be foursilver steel, about Sin. long, turned to thebeing due to the shortage of bolts about locating holes to suit. correct taper at one end. 1941, when the turret was finished. A cast-iron casting is used to form this piece and is machined all over to the dimen- sions given, particular care being taken with the diam. of the recess, as this has to be a BritishCommonwealthScientificConference good fit over the spigot on the base, part (B). THE establishment of a British Common- interest.Thus specialist knowledge which The 5/16in. diam. hole which accommodates wealth ScientificOffice in London ismight at any time be available among the the locating plunger and spring can now be oneofthemainrecommendations to staff of one mission would be available to drilled. To obtain a good finishinthis Governments disclosedinthe Reportofthe other missions. The work would be hole itis advisable to drill to 9/32in. diam.Proceedings of theBritish Commonwealthcarried out more rapidly and economically first, and then finish off with a 5/16in. drill. Scientific Official Conference.(Published byby the provision of certain common ser- Maehining the Base H.M. Stationery Office, Kingsway, London, vicessuchaslibrary,typing,duplicating, Cast iron is also used for the base, partW.C.2, price Is. 3d.) abstracting, indexing and microfilming.It (B), which is machined on top and bottom The OfficialScientificConferencefol- is suggested that the Department of Scien- only, the 14 -in. spigot now being fitted care-lowed on the Royal Society's Empire Scien-tific and Industrial Research should be re- fully to the recess in part (A).A pointedtific Conference last July.Its primary con-sponsible forthese common services, and tool can be used to mark in the pitch circlecern was to discuss scientific collaboration,that the B.C.S.O., London, should at first be of the locating holes, thus ensuring that theywhich had grown up in the Commonwealthhoused in the same building as D.S.I.R. shall be concentric with the spigot.Theduring thewar, and todevise means of locating holes can then be spaced out andensuring its continuance and improvement. Radio Research drilled ',--in.diam.The internal thread in Broadly, the proposal to set up a British There was extensive exchange of in!'or- this part should be cut in the lathe and thenCommonwealth ScientificOffice(B.C.S.O.)mation on Radio Research. Twenty-three cleared7/I6in.diam.and in.deeptoin Londonisthat thevarious Dominion ionosphericrecordingstationsarelikely accommodate the centre spindle (C). Scientific Missions and Liaison Officersin to continu.2 in operation, and recommend- In Fig. 2 the centre spindle is shown inLondon should occupy adjoining offices inations were made for the exploration of the detail. the same building. While retainingfull possibilitiesof stationsatNairobi and in Itis turned from fin. M.S. bar to the autonomy and responsibility to their Graham Land. The future of stations at dimensions given, the thread being formedGovernments they would be abletoco- Cape York, in Australia, Suva and Kodai on the lathe. operate more easily in matters of commonKanal were also discussed. 192 NEWNES PRACTICAL MECHANICS March, 1947 Rocket Propulsion EarlyGermanTransonic Research 1,500 m.p.h.-plus Project Aircraft from Bell and Douglas By K. W. GATLAND (Continued from page158, February issue.) of the ailerons. Fore and aft stability was said to be particularly good. Hechte Hechte wasactuallythefirstofthe "Feuerlilie " series and it might well have takenitsplace in the Rheinland defence system had its development not been guided intootherchannels. Theground -to -air Chalmers H. Goodlin, Bell's twenty-three year old chief test -pilot, hopes to fly a developed weapons that followed the earlyFeuerlilie " XS -1 at 1,700 m.p.h. over 15 miles up. models, however, embodied many of the features proven in the Hechte and F.25, FOR obtaining dataattransonicflow 21.6in. in diameter, had an overall lengthand much of the data found its way into speeds, the wind -tunnel is little moreof 15.75ft. the hands of the full-scale aircraft designer. than useless.There is considerable Firsttestswere made using a booster The Hechte and the F.25 appear to have interference in the working -section betweenrocket, jettisonable as a first stage, in additionbeen almost identical in both size and shape, the walls and from the model supports ;to its driving charge-both di -glycol burning.the only main difference being the power and hence the reason for what in comparisonThe booster section, thrusting at 4,4001b.unit. Here again a bi-fuel propellant was with the static model is a costly item offor six seconds, was first embodied as a fixturethe integral driving force, though not as in equipment, the unmanned free -flight researchon the rear fuselage, but this brought troublethe F.55. The Hechte used a" cold " aircraft. straight away, for unless a vertical or nearsystem operating on T-stoff andZ-stoff verticalascentwasadopted,themissile(8o per cent. solution, H202 and calcium or First German Experiments became unstable immediately after leavingsodium permanganate), which gave1321b. Firstofthesespecialtypeswastheits launching ramp.The obvious remedythrust for from 20 to 25 seconds. The " Feuerlilie," developed by German aero-was to split the large boost rocket into smallermaximum speed attainable was about 92oft. dynamicists. Actually, this did not signifyunits, mounting them as close to the aircraft'sper second, and as with the F.25 and F.55, a specific machine but was a group desig-c.g. as possible, and this was done, usingrollstabilisation waseffectedby ailerons nation which covered at least three distinctfour r,roolb. thrust rockets with satisfactorythrough a gyro link. models. They were originally intended asresults. One such model, in fact, having ground -to -airmissiles, andallthree,therisen to 15,7ooft. from a launch at 7o degrees,Some General Particulars Hechte, the F.25 and the F.55, were designedflew for 4.66 miles.Its final speed (at the Work on the larger model (the F.55) had by Rheinmetall-Borsig and developed at thetime of impact) was M =1.25. only justcommencedwhenGermany Hermann Goring Research Institute, sunk Later flights were planned in which acollapsed, and there is no evidence of the deep below ground in the forest of Volkenrode,liquid -fuelledpowerplantdisplacedtheliquid -fuelled version having flown, though near Brunswick. several were almost com- pleted.The solid -fuelled .F.25 model wasfurtherad- Driven by powder fuel, the F.25 appears vanced,andthereare to have commanded most attention and some several complete ex- twenty models were launched between 1941 amples. One of these, and 1943. tested by technicians of The drawing (Fig.92, top) shows the the U.S.Army shortly external layout and it will be seen that swept - aftertheoccupation, is back wings, with tipfins, were mounted said tohave risensuc- mid -depthofitsslim and nose -pointed cessfullyandtohave fuselage. They were of section N.A.C.A. 0009, remained stable and on swept back at 4o degrees and set at zero course up toitsmaxi - incidence to the body axis. The tail assembly mum Mach number of was rather unusual in that a separate fin 0 1.25,despitethecon- and rudder extended both above and below ventional wing -section the rear fuselage.Each carried a tail -plane, (againN.A.C.A. 0009) the upper one having movableelevators and normal type ailerons. adjustablefor each flight. The machine This particularmodel was roll stabilised by a gyro -servo mechanism, weighed t,000lb., and its working through electro-magnets which moved di -glycol rocket,fitted ailerons at the wing tips. internally, developed fully The rocket motor, which could be eitherFig. 92.-Two models of the " Feuerlilie" series, the F.25 (top) 13,00olb.thrust. From a 109-505 or 109-563 di -glycol type, deliveredand the F.55.Flares, fitted on the fin or wing tips, were sightingacomparisonofthese a thrust of t,toolb. for six seconds.With aids for tine -theodolite operators. figures and thosegiven its aid, the model was launched from a ramp earlier,itwould seem set at 6o to 8o degrees and could reach asecond stage powder rocket and using 90 kg.that there were several size charges specified maximum speed of 72oft. per second. of oxygen and 5o kg. of alcohol, it was foundfor this type. Leading particulars for the F.25 are asthat a thrust of approximately t,toolb. could A cine-theodolite was employed to follow follows :length, 6.56ft. ;fuselage diameter,be maintained for 25 seconds.A di -glycolthe course of these midget research missiles, 9.85in. ;span, 2.95ft. ; wing area, 3.84 sq.boostrocketcontributed6,600lb.thrustthough this system seldom proved reliable. ft., and the all -up weight, 2641b. for the first two seconds of flight, whereuponThe plotting involved a double differentiation itautomatically released and dropped off.which, despite thegreatest care by both Design of the F.55 The bi-fuel unit then, thrusting on its ownoperator and calculator,was a very inaccurate The F.55 (Fig. 92, bottom) was a largeraccount, would take over and the machineprocess, and althoughtheGerman tech- machine and tailless, weighing 1,o4o1b.Itsflying under the control of itsauto -pilotnicians strove to improve the mathematics wings, tipped by large square -cut fins, sweptusually remained stable throughout its com-of the problem, by analytic differentiation and back at 5o degrees and were 8.2oft. in spanplete run. Any rolling tendency was continu-the fitting of high -degree polynominals to with an area of 26.2 sq.ft.The fuselage,ally and automatically corrected by deflectionthe trajectory curve, theystillcould not March, 1947 NEWNES PRACTICAL MECHANICS 193

bettertheirresults.Theidealsolution, that of transmitting data from the model " air -to -ground," was not practicable at the time of the experiments although research was proceeding at the D.V.L. (Deuteches Versuchsanstalt fur Laftfahrt) in an attempt to perfect a radio transmitter for this and similar projects. Since the war's ending, Allied technicians have perfected the " telemeter " with which

itispossible to check with unparalleled accuracy, and at long range, the performance ofpilotlessmissilesandaircraft. Each Vickers -Armstrongtransonicmodelern- , bodies one of these units capable of trans- mitting six instrument readings simultaneously. The data thus obtained has no comparison with that recorded in Germany during the war years and there is much to be expected from itsfurther use inmanned aircraft. This will be all the more apparent when full Forerunner of the bi-fuel rocket engines used in the " Feuerlilie" models was the T-stoff ani details of theBelltransonicexperiments Z-stoff motor of the Henschel H.S. 293 "glider bomb."It developed I,500/b. thrust for 12 can be published. seconds. XS-i, First Tests employed in the Walter bi-fuel units, in whichconditions-whenhisattentionmustbe Latest news of the Bell XS -1 supersonicthe propellant would be forced for combustionone hundred per cent. on his controls- research aircraft is that a first flight underby a turbine driven pump. A series of designisconsiderably relieved by the telemeter, power has already been made. Others, in fact,problemshasunfortunatelydelayedthewhich transmits readings of air -speed, acceler- may have already taken place by the time thesedevelopment of this particular item, and as itation, aileron position and elevator position words are in print. was obviousthatthe machine would beto a ground station throughout the entire Taken up beneath a specially adapted B.29complete in all other respects long before theduration of the test. " Super -Fortress,"themachine wascastpump and ancillariesbecame available,it off at 25,000ft., and then releasing propellantwas decided to install an entirely differentControl and the Strength Factor to one of the four combustion chambers, thesystem. The method adopted was" gas An interesting feature of the control system pilot succeeded in reaching a maximum levelcharging," an arrangement reminiscent ofis that the setting of the tail -plane can be speed of 55o m.p.h. the early German " Mirak " and " Repulsor "adjusted during flight, and asthis might In announcing this Major E. J. Huber, ofexperiments,inwhichgaseousnitrogen,normallyprove hazardousattransonic the Headquarters Army Air Forces, gives thecontained under high pressure, is used tospeed,specialflutterdampers have been designed top speed as1,70o m.p.h. at anforce both fuel and oxygen from their tanksdesignedtominimisethedangerfrom altitudeof 8o,000ft., with the maximuminto the combustion chambers. thissource. The movement isbrought thrust available from the four -unit bi-fuel The gas pressurised systemisnaturallyabout by a powerful mechanical actuator. rocket engine, 6,00o1b.-1,5oolb. each cham-inferior in many respects to the mechanicallyFor the rest of the controls, they are apparently ber. actuated feed.In the prototype machine, theorthodox. motor is limited to a duration of only 2.5 During the early phase of testing, the XS -s Design Features minuteswhenoperatingatfullthrust,will be checked comprehensively by officers Like the Miles M.52 project, the XS -1whereas with the turbo -pump, its maximumof the National Committee for Aeronautics. has a ballistic -shaped fuselage and no wingpower could be maintained for 4.2 minutes.One of their instruments is an oscillograph sweep -back.Basically, the difference betweenCoupled with this, the top speed attainablewith which they will be able to determine the with the alternative power plantstrains sustained by structural members of is estimated to be 1,000 m.p.h.,the wing and tail.The normal pre-flight at 6o,000ft., instead of the 1,700inspections, too, will be carried out with m.p.h.velocityat8o,000ft.,infinite care, for there can be no room for as originallyspecified. Inoversight of the slightest defect.At the addition,therateofclimbspeeds this machine will fly, nothing can be Fig.93. -A piloted leftto chance and the ground personnel aeroplane for supersonic claimed for the machine when fitted with a turbo -pump,have a great responsibility. researchisalso under 45,000ft. per minute, fallsoff The XS-i has been designed to withstand development at the to 28,0ooft. per minute when18g. (or an acceleration of 18 times the force Douglas Aircraft Cor- the pressurised engine is sub-of gravity), and clearly becomes the strongest poration. The precise stituted. craft ever to fly.The wings, for example, design is not yet known, have a skin machined from aluminium alloy, but it may appear like An 8g Pullout having a root thickness greater than lin., this. tapering off to about lin. at the tips.Its When Bell AircraftCor-limitations, in fact, are much more in the these twodesignsisnotgreat,though,poration first undertook the contract fora naturally, as one was " jet " and the other issupersonic research aeroplane-and that wasmake-up of the pilot than in the structure " rocket, " the similarity remains only in thein the spring of 1945-the following minimumof the machine. exterior shape. Actually, the fuselage of the Bellperformance requirementswerespecified.The Pilot machine is rather more plump looking than itsFirst, an 8g pullout at an indicated air -speed The man whom it seems will be the first to British counterpart, which is due to the neednot exceeding Soo m.p.h. ; then, an 8g pulloutoutfly sound is Chalmers " Slick " Goodlin, to provide tankage for the rocket propellant,at minimum speed ;a proof of the specifiedBell'stwenty-three yearoldchieftest - 8,1771b. of liquid oxygen and alcohol. endurance at rated thrust, and take -off (frompilot.He succeeds Jack Woolams who was The overall weight of the prototype (fullythe ground) and climb to 35,000ft. under itskilled on August 3oth, 1946, when a special fuelled, all test equipment installed and withown power.Finally,themachinemustP.39 racing 'plane which he was grooming pilot) is 13,0691b.For all that, it is not a bigrespond satisfactorily to control at Mach-.8o,for an air race crashed out of control into aeroplane, as will be observed from the photo- These characteristics are now being proved.Lake Ontario.The reason for this most graphs ; the length of the first test machineAfterwards, the'plane will be acceleratedunfortunate mishap is given as tail failure. is 31ft. ;its span 28ft., and the height (fromby stages intothetransonicspeedzone Goodlin,anativeof Greensburg,Pa., ground to fin tip) soft. loin. and then, if everything goes well, the throttlelearned to fly at the early age of sixteen, There are apparently to be at least twowill be opened wide in an attempt to confirmlater serving with the R.C.A.F. and the R.A.F. of these research aeroplanes, the first a " flyingthedesigner'smostambitiousestimate.from February, 5945, before his transfer to test-bed" for the second. The earlier version,This does not necessarily imply that the samethe U.S. Navy in December, 1942. After his moreover, will not be capable of reaching thebasic design as recently tested will remainhonourable discharge from the Service, he speed for which it was designed because ofunalteredattransonic and supersonicjoined Bell Aircraft Corporation, and has the substitution of an alternative power unit.speeds. The probabilityisthatseveralbeen test flying since January, 1944. modifications(principallyinwingform) A Gas -charged Engine will be embodied as fresh data is brought inA Douglas Project Originally, the engine for the prototypefrom each successive test flight. News of progress with the XS -1 is followed was to incorporate a fuel system similar to those The pilot'staskunder transonic flightby rumours of another research aeroplane, 194 NEWNES PRACTICAL MECHANICS March, 1947 similar in purpose but very different in design, a project by the Douglas Aircraft Corporation. The machine is said to be rocket powered and as nearly a " flying -wing " as itispossible to obtain in a small high- performance type. Actually, the need for con?eining compara- tively large proportions of rocket propellant makes some form of fuselage essential in these thin -wing research aircraftj; and then there is always the installation of pilot and controls to be considered. The Douglas project, in all events, is mainly wing, but with a slim pencil -like fuselage which projects for some distance beyond the root leading edge, tapering away to a point at the nose. The body form is naturally less slim toward the rear where the pilot is accommodated, presumably along with the main tanks and rocket motor. A single vertical fin and rudder The prototype Bell XS-i with which it is hoped soon to reach r,000 m.p.h. at 6o,000ft.Its emerges conventionally from the rear fuse- engine comprises four separate combustion chambers-each capable of 1,5oolb.thrust-d lage and there is no tail -plane. operating on only one, the machine has already flown at 55o m.p.h. The above few particulars of what promises to be an interesting aeroplane are indicatedthe conical bow wave thrown off from that The " needle-sharp " nosing on a swept - pictorially in Fig. 93.The drawing is notregion hits the leading edge of the wing atback layout should prove effective in counter- intended as an accurate impression of theconsiderably reduced velocity. The reductioning at least some of the more major problems design, but rather to illustratethelikelyin flow speed is further assisted by the pro-which will arise when pilots come fully to arrangement of such a machine as the onenounced sweepback of the wings with thegrips with sound.It will be interesting to described. result that the overall drag is greatly decreasedlearn more of this Douglas venture and also The reason for the length of fuselage forwardand the liftsuffers not so drastic a drop.to discover the truth of a report that most of of the wing can be explained quite simply.Stability also derives a benefit in that changethe main U.S. aircraft builders are actively Attrans -sonicspeeds, the highly refinedin trim during travel from one speed zonepreparing programmes of research which call nose will have the effect of breaking down theinto another is not so marked. At least, thatfor " faster -than -sound " piloted aircraft. shock " front " so that the air accruing inis the theory ! (To be continued) Glues, Cements, and Adhesives -2 Cold Glues, Pastes, Gums and Their Uses

BY the word adhesive I refer to all such By " HANDYMAN" about 75 deg. Fahr. these granules split up " stickystuffs " as employedfor (Continued from page 12o, January issue) and adhesive " glutens " and " albumen " are formed. Boththesesubstancespossess uniting paper, cardboard, leather andfluous adhesiveistherefore recommended. smaller wooden objects to each other, and,If there is bad contact between the unitedpowerful adhesive qualities, and the paste naturally, the liquid and other cold gluesparts, the area of the exposed glue is con-is of a double tenacity when they are both which ordinarily would have been consideredsiderable and dampness in the atmosphereliberated. Decomposition of flour and starch in the last article may be classified with thecan more easily penetrate and weaken the pastesisdue to the fermentation of the adhesives:the gums, the liquid fish -glues joint.This may not be quite so seriouscereal constituents, and therefore preserva- and starch pastes. tivesarenecessary. Pastesmade from a matter with glues of the nature ofCroid " farina (potato starch) are not so strong as or" Seccotine "as with carpenter'sglue,wheat or rye flour pastes, and sometimes Liquid Glues whichismost susceptibleto atmosphericthe addition of one of the glues is resorted There is nothing much to say about thechanges, but thereisbound to be someto.With the hide glues sucha pasteis making ofthese glues, except that theydetrimental action on the adhesiveifthemore liable to putrefaction.The mixing of are derived from bones and offal of fishes,joint is not a close one.Grease is an enemypastes,withsilicateofsoda (common and that the edibleisinglassisa highlyof all adhesives, and therefore surfaces which" water -glass " or " preservatives ") can be refined product made from selected partsare to be attached to each other should betried, but the difficultiesof keeping them of the fish, bearing much the same placefree even from the natural oils which areare increased.Such pastes tend to liquefy in :elation to common fish -glue that gelatinepresent on the fingers.In winter, cold glueswhen they are put into closed retainers. does to animal -glue.Isinglass, however, isare more viscous-even hard-and if, when The preservatives for pastes are carbolic sometimes used for the finer cements, andthe tubeissqueezed, the adhesive comesacid,oilofcloves,camphorandother is therefore not an adhesive in the ordinaryout in a sort of crystallised form, it shouldessential oils.In using that powerful disin- sense of the word, except where itis usednot be used without slightly heating.Infectant, " Lysol," as a preservative in home- in the making of "court plaster," an adhesivea cold room, or on a winter's day, it is bestmade flour paste, I found that it destroyed silk for cut fingers.Liquid fish -glues areto place the tube of adhesive in a cup ofthe adhesive value of the paste-especially supplied in collapsible tubes in all sizes andhot water for a few minutes before using.if the quantity was overdone-and turned qualities and under various trade names.Seccotine tubes are usually supplied withthe paste quite brown.I now use nitro - Seccotine is the forerunner of this most con-a metal peg with a looped handle end, whichbenzine.This is a chemical strongly smell- venient form of adhesive, and a small tubeis replaced in the nozzle after use.Thising of almonds and is an admixture to many is obtainable for a few pence. isthe simplest and best device to prevent The liquid glue is known under the nameloss ofglue and to ensure a ready flowbrands of office pastes. of" Croid," and isaquality of cold gluewhen the glue is required to be used again.Cold -water Paste which, besides having a general utility, is toWhere this sort of stopper is not provided, be recommended for small joinery and otheras in the cheaper qualities and sizes, a small Liquid ammonia and other alkalies have woodwork where asmall quantity of thenail or a stout household pin will serve thethe power of causing such separation, and agglutinantisrequiredata time.Itis same purpose. wheat, flour or potato starch can be con- excellent for model -making purposes. verted into a mass of stiff paste, which will Pastes dry up.The resultant horn -like mass will These are usually made from one of thenot decompose and can be ground up into Using Liquid Glues flours or starch and there are innumerable apowder.This powder, usually sold as As in the case of .hot glues (carpenter'srecipesin commonuse. Dextrineisa " cold -water paste," can then be mixed with hide glues) the minimum amount of coldmanufacturedsubstancewhich isalmostwater into a paste as required.The only glue should be used in making a joint, andidentical with starch and is sometimes termeddrawback to this stuff is that thepresence perfect contact between the two partsis " British Gum." The granules in starch andof the strong alkali may cause the paste to essential to the strength of the job.Rubbingflours are insoluble in cold water, but whenadversely affect coloured objects. the objects together to exclude the super -heatedwith waterofatemperatureof (To be continued) March, 1947 NEWNES PRACTICAL MECHANICS 195 Electrical EngineeringDevelopments An Interesting Account of the Progress -Made by the British Thomson -Houston Company in the Reconversion from War to Peacetime Production

AstheyearinwhichtheBritishturbines, and Thomson -HoustonCompany,Ltd.,schemes for a variety celebrated its jubilee, 1946 has beenofapplicationsfor a memorable one in the history of the com- powerstation,in- pany, which has had its large manufacturingdustrial, marine and capacity fully occupied in the execution oftraction require- orders for all kinds of electrical plant forments are under service at home and overseas. consideration. Orders ranged from large power station Mechanicalrecti- and industrial plant to Mazda lamps of allfiers and control for types, and the various domestic appliancesprecipitationplant, requiredfortheextensivehousingpro-unifiedcontrolfor grammes now under way in this country.the stokers and fans Many large lighting installations have beenof boiler, s o o t - completed, and street lighting with " Warm -blower and temper- white " fluorescent lamps has been an out-aturealarmequip- standing development. mentsare oth er productsfor which therehasbeenan Power Station Plant active demand. The Central Electricity Board's programmeEngine -driven ofadditions togenerating plant has pro-Alternators duced a number of orders for large turbo - alternators, including three 75,000 kW three A fourth 3,000 cylinder 1,5oo r.p.m. machines of the new kVA flywheel -type Barking " C " (County of London E.S. Co.,engine -driven alter- nator was c o m - Ltd) powerstation, and two 6o,000 kWpleted for a Jerusa- two cylinder 3,000 r.p.m. units for Balfour lem publicutility BeattyandCo.,Ltd. Several orderscompany and repeat for 50,000 and 30,000 kW machines,orders were received duplicatingunitsalreadyinhand,area for two more. Two welcome recognition of the importance in3,500 kW flywheel, present circumstances of repetition of exist-type i85 r.p.m. alter- ing design and construction.Several 30,000nators were ordered kW units are in course of erection and afor a station which 200,000 kW setfortheScottishCentral already containssix B.T.H. 3,500 kW water -turbine -drivenverticalalternatorfora ElectricPower Company'sBonnybridge2,500unitsof this hydro -electric scheme in India. station was put into service during the year.type. The hydro -electric and engine -driven alter- nator departmentshav,..ialso received im-Transformers load tap changing equipment for the C.E.B. portant orders. Large transformers, ranging from 45 mVA and for the North Eastern E.S. Co. Among downwards, include a number fitted with on-the overseas orders from India,Australia Increasing interest is being shown in gas and South Africa are two 4o mVA banks (10.5/88kV),withstationandauxiliary transformers for the Orlando (Johannesburg) power station, and three 37.5 mVA 1t/66 kV unitswhicharebeingsuppliedtothe Victorian State Electricity Commission. Switchgear Perhaps the most interesting iteminthe activities of the switchgear department was theinstallation ofsix132 kV " Aerojet " 1,500 mVA circuit breakers in the C.E.B. substationatAndover. An" Aerojet " breaker for tto kV fitted with a new design of " allporcelain " blast head and incor- poratingasimplifiedcontact arrangement, has been developed for the Madras Govern- ment.A new design of high speed oil cir- cuitbreaker for 2,500 mVA duty, which incorporatesresistanceswitchingand is capable of operating in 3cycles, has been manufactured. A new design oftype V -Laircircuit breaker, incorporating an improved form of arc chuteis now availablefortoo and 15o mVA breaking capacity at 3.3 kV. A large orde: for Class AL truck -type switch - gear with type V -L air circuit breakers has been completed. Marine Department Special interest is added to an order now in hand forthefirstfour -enginediesel- electric tanker using A.C. by the fact that a combustion turbine is now under manufac- B.T.H. 4,850 h.p. motor for 32in. reversing mill, on test at Rugby works. tureatthe Rugby Works which willbe 196 NEWNESPRACTICAL MECHANICS - March, 1947 been ordered by aa 32in. reversing structural mill with ampli- Nottinghamshire col-dyne control ; two aluminium mill installa- lierytoreplaceations ; and a small reversing cold strip mill 1,500 h.p. 49.5 r.p.m. for special alloysteel.Amplidyne control machine.An ex- isgiving very satisfactory resultsinmill ample of the alter-operation. A z,000 h.p. induction motor native method ofdrive for a 3 -high roughing mill has recently using large minebeen shipped to Southern Rhodesia. Other carsisthe mediumimportant orders for mill plant and auxiliaries horse - power A.C. are in hand. winderfittedwith theB.T.H.patentPaper Mills speedcompensated Orders from home and overseas for paper braking control,mill equipment include a large contract from which is being a SouthAmericancompanyforA.G. manufactured fora sectional drives and auxiliarymachinery ; collieryinDerby-additionalmotors and controlequipment shire, where the carhave been added to the order during the capacityhasbeen year.The B.T.H. Company is supplying a raisedto42tons number of A.C. variable speed commutator and the rope speedmotors ranging up to zoo h.p. for individual reducedtot4.4ft. driveofsmaller papermachines ;where per second. extralong speed ranges are required an A number o felectronic speed regulator is being fitted. schemes for the re- These equipments include one for an placementofsub- Indian paper mill.One of the latest B.T.I-1.` sidiaryropehaul-design of selsyntie-insectional drives for ages by conveyoroperating a cellulosefilm -making machine installations,asre- is now in production. commended inthe ReidReport,haveLifts and Escalators been prepared. A typical equipment, Additions to the lift installationsat the now being installedRugby works will give greater variety to the ataMidland col-types of lift motors available for demonstra- liery,comprises a tion to visitors. Variable voltage sets for high 140 h.p. 3,300v. speed lifts are in hand for London and for flameproof squirrelCanada. A variable speed A.C. drive for a Section of type Ca'A self -boosted aircraft magneto, showing position cagemotor,which L.P.T.B. escalator represents a new depar- of the pump gears. drives throughture, employing a type CHT motor with hydrauliccoupling. three -speed _selectorswitch,enablingthe It 'isstartedescalator speed to be changed automatically ; substituted eventually for one of the dieseldirect by flameproof contactor gear;eventually, five speeds will be available for alternator sets ;this is the first British mer-the controlcircuit being interlocked withlarger installations. cantile marine application of the gas turbineother conveyors by a belt -driven centrifugal tobe announced.The experience to bedevice, with a Thrustor-operated brake toFractional H.P. Motors gained from this installationwill be mostprevent run -back. - There are five 75 h.p. A- sectionofa B.T.H.factory.at valuable when more ambitious arrangements,conveyors in the same scheme.- : in which the gas turbine will form the main Newcastie-under-Lyrne, has _been :devoted to orthe only powerproducingunit, - are the manufacture of -fractional hOfse-poWer developed. Another interesting marine instal-Rolling and Tube Mills motors to supplement the other works en- lation is the electric cable -laying machinery A number of new drives for a variety ofgaged in producing these machines. A com- -the first of its kind-in the cable shiprolling mills have been placed in commis-prehensive range of fractionalh.p.flame- Monarch, which completed very successful sion.These include a 4,85o h.p. drive forproof motors, covered by Buxton Certificate trials in the early part of the year.

Traction This departmentisbusy withalarge number oftrolley- bus equipments, recent orders including 52 for Wolverhampton, 15 for Derby, and 12 for Mexborotigh.For the London Passenger Transport Board an order hasbeen received for225 PCM control equipments which will be generally similar to the 855 equipments supplied for the 1938 Tube stock, but will incorporate improve- ments in the layout and design of the indi- vidual parts tofacilitate servicing and' re- placement with the equipment in position. The electrical side of the power plant of a diesel-electric locomotive for mixedtraffic isto be supplied to the L.M.S. Railway. This will have two 2 -axle bogies, with all four -axlesmotoEed. The newbattery vehicle control equipment developed in 1945 is now in full production ; orders for 500, including motors, have been received, and further large orders are expected. Mining Plant The supply and installation of a number of equipments has beenproceeding. For oversea mines two winder equipments of more than 2,500 h.p. are being manufactured; and three of at least 3,000 h.p. are about to be installed.In order to handle large loads at low speeds and thereby to attain maximum efficiency a 2,000 h.p. 37 r.p.m. D.G. Ward Leonard controlled skip winder motor has A .modern shirt factory lighted with Mazda 80 -watt fluorescent lamps. March, 1947 NEWNES PRACTICAL MECHANICS 197 for use in Group II gases (of which petrolduction, 35 mm. and x6 mm. sound film Council of Industrial Design for inclusion in vapour isatypicalexample), isintendedprojection equipments, and carrier frequencythe " Britain Can Make It " exhibition.This primarily fgr use in kerbside petrol pumps ;wire broadcasting-the first relay installation fitting is one of a new family of 8o -watt and orders halie beenreceivedformanyof this type was inaugurated at Rugby in4o -watt fluorescent lamp fittings already in thousandsfor thisand other applications.November. demand for offices and business premises. The varied requirements of the several main users have been met by the production of oneAircraft Equipment Street Lighting basic design. Tests ofa B.T.H. turbo -starterofthe The most outstanding development has Small special motors for the film industry" Cartridge " type on agasturbine aerobeen the introduction of a Mazdalux lantern (three-phase slipring machines, of which aengine were very successful, and prototypesaccommodating three standard Mazda 8o - number will operate in mutual synchronismare now being made.In the ignition equip-watt " Warm -white " fluorescent lamps. The when connected toa common distributorment for the new 33o h.p.s-Jpercharged first experimental installation was made in unit) ; and a small shaded pole motor (typeGipsy Queen series 70 De Havilland aeroHigh Street, Rugby, closely followed by an BP 1304), available for outputs of 3, 5 andengine, " rotating magnet "type magnetosinstallationinOld Bond Street, London. 7 watts, and intended for driving table orare used in place of theearlier " rotatingMany inquiries have already been received window fans, condenser cooling equipmentarmature "type. The newself -boosting from public lighting engineers. on refrigerators and general air conditioningmagneto which has the distributor brush A range of 16 side -entry lanterns,all of plant, are among other recent developmentsholder gear enclosed to form a pump, pro-the same basic design, has been developed in this field. duces 7.6 kV. at 34,000ft., and with the fortheaccommodation of everytypeof aid of the pump, 6 kV at over 5o,000ft.Thevertically operated street lighting lamp. Industrial Heating firstthousand of these magnetos are now Another new lantern is that designed for The standard screw type immersion heaterbeing made by the B.T.H. Company. the lighting of Group A roads with 250 -watt has been used insteam gpnerators, withLamps and Lighting or 400 -watt standard Mercra lampsina working pressure up to3o1b.sq.in. ;for horizontal burning position. higher pressures flange -mounted heaters have The Mazda 4o watt fluorescent lamp has been supplied. A scheme has recently beenachieved almost as much popularityasits developed for feeding a lead melting furnace,older 8o watt counterpart.The efficiency ofSchool Lighting the molten metal being pumped through an" Daylight " lamps has been greatly improved During theyear many localeducation electrically heated tap to the metal mould orand itis hoped that the improvement willauthorities have sought the advice of B.T.H. to the processing machine. shortlybeextendedto" Warm -white "lightingengineersonlightingplansfor Reclaiming ofvitreousenamelledsheetlamps. future schools. steel parts has been achieved by treatment in The range of compact elongated Mazdalux special caustic baths heated by Pyrobar im-lamp auxiliaries has been extended, and madeMines Lighting mersion heaters. To prevent damage to cable it possible to develop a complete uniform connections Pyrobar oil immersion heatersrange of 4o watt and 8o watt single and two - Experimental fluorescent lighting installa- lamp fittings. tions have been completed in the Binley and for tempering bathshave been designed, Birch Coppice Collieries, proving that there with their terminals extended away from the isa great future for fluorescent lighting in hot bath. Industrial Lighting Many large-scaleinstallations have beenunderground roadways.Further experiments completed, and itis becoming increasinglyto extend the field of application are under Electronics Engineering way. In addition to the Government work stillevident thatarchitects andconsulting in hand, much development has been carriedengineers are realising the necessity of giving out on improved and simplified forms ofserious consideration to lighting in the earlyInfra -red the controls shown at the Symposium andstages of planning. A new type of lamp with an internal Exhibition heldat Rugby inJuly.Itis reflector which does not require cleaning or anticipatedthat marineradar equipmentsCommercial Lighting polishing has been introduced.Itis hoped willbeinproductionin1947. Active A new fittingof B.T.H. design fora that production of this lamp in the com- developmem: has taken place in sound repro-4o -watt fluorescent lamp was selected by the pany's works will soon be started. The Sawyer l'-Viewmaster'4:1 THISnewinstrumentembodies'thepurchase tax, and that of the reels, 2s. each. scientifically applied principle of theNew releases will be available shortly and stereoscope, redesigned on modern lines and willincludereelsofEnglish scenes and with the added attraction of three-dimen- life,Switzerland, The Holy Land and, sional pictures in full colour Kodachrome. especiallyfor the childen,theirfavourite fairy stories-all in three-dimensional full - It is slightly bigger than the average paircolour Kodachrome. of opera glasses, beautifully made in durable plastic and equipped with perfect, accurately The Sawyer "Viewmaster," is made in ground lenses-specially adjusted for stereo-England for thesole distributors, Messrs. scopiceffectandfullyguaranteed fora Victor Animatograph Corpn. (London), Ltd., year after purchase. of 9, Cavendish Square, London, W.I. "Viewmaster " pictures, photographed by special colour -photo process, are mounted on !- easily changed reels . . .minutely adjusted for correct focus and ready to use ;a flick of the finger changes the picture. Apart from its uses as an educational and enter- tainment medium its applications in the world of business are very numerous. For instance, ithas great valueasasaleman's aid- especially for those products where samples and details of manufacture cannot possibly be taken to a client's desk. The represen- tative can show his prospective customer full - colourthree-dimensionalpicturesofpro- ducts, application, processes, colour ranges, textiles,installationsinfarpartsofthe world, etc. The" Viewmaster" in use, and (left) The "Viewmaster " and reels-there are enlarged view showing the front over200subjectstochoosefrom-are open and the reel of Kodachrome obtainable from photographic dealers.The pictures. price ofthe " Viewmaster "isr5s.,plus 198 NEWNES PRACTICAL MECHANICS March, 1947 Trace Elements A Modern Chemical Enigma Outlined

FOR thehealthy growth and develop- By J.F. STIRLING number of plants, but the essential character ment of both animals and plants certain of this element was not demonstrated until basic elements are required to enter some fifteen years afterwards when the agri- intotheirnutrition. Such elementsare In various laboratories throughout the worldculturalscientistsatRothamstedexperi- nitrogen,potassium,calcium,phosphorus the work proceeded quietly and patiently.mental station proved conclusively that at and, to some extent,iron. Additionally,Ultimately, the results began to come through leasttwenty diseasesofplantscould be of course, animals need oxygen for respira-little by little.It began to be proved thattraced to the complete absence of boron in tion, andthe animal machine also needsthere exist elements whose presence in thethe soil. very small but regular amounts of certain A highly theoretical piece of research, you complex organic substances which we call might think, and one without very much vitaminsforittoworksmoothly and practical import. But not so, because one efficiently. of these boron -deficiency diseases happened But increasingly during the last few years to be the then troublesome " heart rot " or it has become recognised that the above list " crown- rot " of the sugar- beet, which in a does not comprise the whole of the essentials good degree opposed our efforts to -establish of healthy plant or animal life.There has asuccess:titsugarbeetindustryinthis now entered into the picture of Life's pro- country. Hence it was that the discovery cesses the conception of what, for want of a of the essential nature of boron in asoil more accurate term, is known as the " trace gave us the weapon we wanted to combat element," that is to say of an element whose an agricultural disease wh.dh might ultim- presence in the merest traces seems to be atelyhave beenthe ruination of a very more or less essential for the well-being of necessary industry. the plant or animal. In a- similar way, it was shown that the You may think of a "trace element" as " raan " or " brown heart " disease of turnips a mineral vitamin, if you like, although the and swedes was due to lack of boron in the analogy is not a perfectly exact one, for the soil. vitamin seems to function in an altogether different manner from the trace element. Indispensable Boron It was the agriculturists andthebio- Boron, indeed, seems to be a very indis- logists-not the chemical scientists-who first pensable element in the growth mechanism stumbled on the conception of the trace of plants. Root crops are the most sensi- tive to its absence.Without it,the fibres element. -They were puzzled, for example, as to why two areas of land having similar of these roots cannot form themselves pro- soils and similar climatic conditions should perly. The root becomes stunted. It is produce entirely different crop yields, one unable to extract sufficient nourishment from ofthe experimental lands giving bumper the soil.Hence the plant languishes and cereal crops, the other giving poor, miser- ultimately dies. able results. They were perplexed, also, Why tit'sshould be so is unknown at as to why sheep grazing on certain lands present.But the fact remains and continues thrivedexceedinglywell and why other to present a subject for the most interest- identical breeds of sheep feeding on similar ingresearchtothe modern agricultural pastures should be poorly nourished and chemist. even diseased. Quite a lot of varying plant diseases can It was from considerations such as theseHealthy, well -grown barley.Abseme from thebe traced to lack of boron in the soil.The that the idea of the trace element graduallysoil of copper, zinc and manganese as trace" browning " disease of cauliflowers, and the arose. Clearly,itseemed, the successfulelementsrenderssuchcerealcropsweak," cracked stem " trouble of celery are both pasture lands and the soils which producedimproperly formed, stunted, and liable to diseasedue to boron deficiency. So, too,isthe the prolific crops were the ones which con- attacks of mildew. " internal cork " diseaseofcertain apple tained something which the other lands did trees, whilst that peculiar disease known as not possess. Yet, in their average routinesoil in minute amounts is absolutely essen-" topsiekte," which withers the leaves of the chemical analysis, such soils were identical. tial to the good growth of crops which aretobacco plant, has the same cause. So, one by one, agricultural scientists setgrown in such soils. Only traces of such And what is boron ? It is a non-metallic to work in order to ferret out the under-elements in the soil were shown to be neces- element which is related to aluminium. Its lying reason of these observed differences.sary, amounts not exceeding a few parts per million in the soil. Indeed, some of the trace elements, such as, for instance, copper, are actually poisonous when present in sub- stantialamounts. Nevertheless,inthese minute traces, they seem to be essential. Active Investigations Not very much is known about agricul- tural and biological trace elements at the present time. But more and more labor- atoriesare taking up the investigation of these mysterious elements and are actively endeavouring toascertainthe underlying mechanisms of their now indisputable effects on plants and animals. So far as we know at present, the trace elements concerned with the well-being of the plant are four in number, viz., boron, manganese,copperandzinc. To this quartet of elements may be added another suspected trace element in the form of the" Cabbage Rust." A highly magnified view of a rare metal molybdenum. section of a diseased cabbage leaf affected by A drop of human bloodhighlymagnified, Boron is the most important of the agri" rust," showing the invasion of the leaf cells rendering the red hcemoglobin corpuscles clearly cultural trace elements. As long ago as by destructive fungoid bodies, which feed on the visible.Lack of manganese traces in the body 191o,itwas shown that the presence oflivingcellsof theleaf and destroythem. is supposed to inhibit the formation of thesecertain amounts of boron compounds in theSuch a disease is often symptomatic of trace - corpuscles and to bring on a condition of ancemia. soil is required for the healthy growth of a element deficiency in the soil. March, 1947 NEWNES PRACTICAL MECHANICS 199 compounds are plentiful, particularly in vol- iodine supply we run the risk of goitre andFluorine canic regions, and for a long time most ofvarious other troubles. There. is another element which seems to our borax and boric acid came from the Manganese is indispensable to the animalbe essential to animal economy. Thisis waters of these regions.Yet, owing to theorganism (and probably, also, to our ownfluorine,the most active member ofthe difficultyofitsextraction, boronitselfis bodies) because, as previously mentioned, it" halogen " family, of which chlorine, bro- seldom seen, and there are practically noseems to be concerned in the mechanism ofmine and iodine are other members. uses for it. haemoglobin formation, haemoglobin being, In minute quantities, fluorine is found in Nevertheless, its action on plants is posi- ofcourse,theredactiveprincipleof the teeth of humans and animals.Hence, tive enough. Apply boric acid or borax totheblood. If,therefore, without theas it must be assumed that certain traces of a " deficiency " soil and the plant diseases yetmysteriouscatalyticeffectoftraces this element are necessary.Yet if man or due to its absence gradually vanish. Even of manganese you cannot assimilateanimals drink water having a high fluorine the mere spraying of the crops with a borax sufficientirontoproducethenecessarycontent, the normal processes of tooth and solution will sometimes cure the disease.In blood hemoglobin, the effect ofthislack of bone formation are at once upset. There a word, the application of about tolb. of boraxcan readily be imagined.The same appliesis brought about the well-known " fluorine to the acre of land is an almost sovereign alsoto various breeds of cattle and othermottling " of the teeth and a softening of remedy for troubles caused by the lack of this land animals. the bones.When rock phosphate is fed to element. Cobalt Deficiency animals, these symptoms may come on if, Copper,aswehavealreadyseen,is Cobalt is a trace element which seems to asis sometimes the case, the phosphate is another trace element.Its complete absencebe indispensable to animals but not to plants. from thesoilisresponsibleforvarious Probably it acts in a similar manner to man- diseases of fruit trees not only in England,ganese, because in experimentalrats,its but in many parts of the world. An instance presence in the food has been shown to result of copper deficiencyisto be seen inthein an increase in the number of blood cells. In Australia, cobaltdeficiency has been shown to be the cause of various wasting diseases of sheep. What is known as " Coast disease "in Australiahas been cured by feeding minute amounts ofsoluble cobalt compounds to cattle.So, also, has the im- portant " bush sickness " of cattle in New Zealand.The disease of sheep known in this country as ," pine " seems also to be a caseofcobaltdeficiency. Ithasbeen experimentally cured by the addition of from 2to201b. of cobalt chloride peracre to Scottish soils. Then there is molybdenum, the rare metal which has been used considerablyinthe constructionofradiotransmittingvalves, The mysteriousmolybdenum. Whetherit and in other high -power electrical vacuumHighly -magnified view of a portion of a section behaves as a trace element or otherwise has nottubes.Molybdenum has been shown to be yet been settled.Nevertheless, in view of its of a wheat stem,showing parasitic fungus the cause of thecattledisease known asgrowing on the surface of the stem. The individual rarity in the metallic state, a strip of it as shown" teart "incertain Worcestershireand here is seldom seen. plant cells of the wheat stem are plainly seen, and Somersetshire pastures. Yet there is some evi-alsothe gradual penetrations of the fungus dence to show that its entire absence from" roots" into them. A condition such as this is " exanthema "or" die -back "diseaseof thesoilisinjurious to the well-being of plums, apples, pears, prunes and citrus fruits. often due tolack of trace elements-notably animals, if not of plants.But in the case of copper and zinc-in the soil. Put copper into the soil at the rate of about this rare metal the verdictis,as yet, one 21bof copper sulphate per acre and youof " not proven." rich in fluorine.Indeed, in extreme cases cure the trouble.But exceed this amount of this " fluorinisation," general emaciation, appreciably and you run the risk of killing thickened joints, and even a form of rickets the trees, for copper in more than the most may all come on.Yet, strange tosay, in minute traces is a well-known toxic agent. minuteamounts,fluorine,aswehave The same appliestozinc. Without a observed, seemstobe essentialto tooth minute trace of zinc in the soil, crops lan- formation. guish and become liable to be attacked by As regardszinc, whichisessentialto mildews of various descriptions. certain forms of plant life, no known case Then there is manganese, another metallic of cattle and farm animal disease has yet trace element whose presence in soil is indis- been ascribed to zinc deficiency.On the pensable toa healthy plant life. Remove other hand, experimental rats which were assimilable manganese from the soil and the fed on a perfectly zinc -free diet for several plantsbecome, asitwere,chronically monthswerefoundtohavedeveloped anemic.It is thought that the presence of anemia and wasting diseases, due, appar- manganese in the soil acts by assisting in the ently, to poor nutrition.Hence, even in the mechanism of iron -uptake by the plant, but biological world, zinc seems to function in the chemical process has by no means been some ways as a vital trace element. worked out yet. The metal magnesium canhardlybe regarded as a trace element in the world Animal Trace Elements of plants, for just as iron is an indispensable Inthe animal organism, trace elements constituent of the red hemoglobin of animal are equally as essential as they are to plant and human blood, so, too, is magnesium a life,andthecomplete absence of them component of the green chlorophyl of plants. brings about cessation or, at least, disorgan- But it has been noticed in the case of sheep isation of life's forces. Animal trace elements and other animals that deficiencies of mag- are at least five in number-copper, cobalt, nesium have been associated with the onset manganese, zinc and iodine-but there are of convulsions.What is known as " grass probably considerably more awaiting recog- tetany " or " grass staggers " in sheep has nition. been shown to be due to low magnesium Of the above named, the last one-iodine values in the blood and may be cured by -isthebestunderstoodasregardsits dosing the animal with magnesium salts physiological mechanism, for it applies to our or by providing it (as recommended by the own bodies as well as to those of the lower MinistryofAgriculture)withadaily animals. An enlarged section of a human tooth showingminerallickcontainingsopercent.of A minute intake of iodine is essential forthe sensitive " pulp " or inner tooth materialmagnesium oxide. animals and man. From it the body buildsand the hard external enamel layer around it. up the very necessary organic compound Whilst the enamel always contains fluorine inConcerning Copper known as thyroxine. This isa complexminute quantities, excess of this active element Copper asatraceelementisjustas iodine compound which regulates the generalin the body destroys the enamel and causes itessentialfor animalsasitisforplants, mechanism of the body. Without a sufficient to crumble. -althoughinbothinstances an excess of 200 NEWNES PRACTICAL MECHANICS March, 1947 itacts the other way and becomes highly chemical mechanism isthe same in both poisonous.In Holland, in Australia and in instances we do not know. New Zealandadiseaseof young lambs knownas" swayback,"which wasfirst Agricultural Geology associated withleadpoisoning, has been Trace elements in thetoilare derived shown really to be due to a copper deficiency from the various rocks of the neighbour- in the body.Animals which have died of hood.There isbeing set on foot at the this disease show cavities in the brain mass present time a number of modern geological and an almost complete absence of all traces studies which seek to estimate the amount ofcopperintheblood. Whetherthe and variety of trace elements in thesoil observed deterioration of the brain matter of any given neighbourhood from a con- is due to the copper deficiency has not yet sideration of its geological surroundings and been proved.If, however, itis shown to environment. " Agriculturalgeology "is be the case, it must then appear that traces the name which has been proposed for this of copper are essential to the working of new branch of applied science. the animal and, no doubt, to the human brain.Here again, however, verylittleis The modern study of the trace elements, althoughithas only just begun inreal yet known of this interesting subject. earnest, shows us at once how complex and Instances could be multiplied of animal stillintrinsically mysterious arethe basic diseases being proved to be due to certain mechanicsofanimal andvegetablelife. elementdeficienciesinthe body, but to The general balance between health and extend such examples would serve very little disease, between well-being and deteriora- purpose. tion,isfinely poised.Not onlyiswell- We have,however,sufficientevidence balanced general nutrition required for plant before us to show that what are called " trace and animal life, but fine control of the life elements " (and sometimes " minor forces which are generated by such nutrition elements ") do in actual fact perform a very is also indispensable. important function in both the plant and the animal economy.But what mechanism In -thiscomplexandstillinexorably they involve or create is very much a matterThe deep purple or violet vapour of iodinemysterious business the vitamins are con- fortheresearchscientistofthepresentcontained in a flask.This element is highlycerned, but the trace elements play no less time. important to animal life,its absence bringingimportant a part.It is, therefore, the busi- nessof modern scienceto endeavourto Whether the action of these trace elementson various physical and even mental trouble.discover not anly how each trace element in the human body is similar to their effect fluorine,manganese and probably copperplays itsallotted part, but also how they inthe animal body isnot certaininall have broadly similar effects in both animalare all relatedin their actions one to the cases.Ttue itis that deficiencies of iodine,and human organisms,butwhetherthe other. The Model Aircraft Exhibition A Brief Review of Some of theFine Model Aircraft and Miniature Engines Seen at Dorland Hall By the MARQUISofDONEGALL shocked I was at a certain incident during my tour of Dorland Hall, where the Third NationalModelAircraftExhibitionwas being held. I was inspecting one of the boothsat which components for this science are sold. An argument was in progress. " But, madam, you will need two rubber tyres, not one." " I tell you I want one rubber tyre, and if you really want to know the reasonit is because I want it for my dog."

A flying model of the Sandringham Flying Boat. MANY yearsagoIlearnedtotakethatunfortunate people who build andflymodelcoincidence I have aircraft-aeromodellers, they call hada greater themselves-veryseriously.. Ihadjustregardforaero- acquired a Gypsy -Moth and was inthatmodellers:they firstflushofswollen-headednessthroughareatleast on a which all A Licence pilots have at one timecomparativelysafe passed. At this point a friend of mine, whose wicket. hobby of throwing things into the air on Ionly mention the end of a twisted piece of elasticI hadthisgreatrespect been inclined to belittle, won the WakefieldinwhichIhold Cup andreceived a goodmeasureofaeromodellers i n encouraging publicity in the Press. On theorderthat y o u same day I dented my Gypsy -Moth andshould understand A miniature aero engine seen beside a matchbox. With a bore of .75in. receivedaquiteunmeritedmeasureof the better how and a stroke of .815in., this tiny engine is capable of 5-6,000 revs. unkind publicity in the Press.Ever sinceprofoundly per minute. March, 1947 NEWNE$ PRACTICAL MECHANICS 201

Dorland Hall shook toitsfoimdations,Fortress, a D.H. 108 insilver, by H. F.brothers have been selected for the King's and Ionly wished that H. M. BatemanFreeman, of Gillingham.L. G. Temple,flight,andwillbeusedonhisSouth himself had been present. of Colchester, gets a well -deserved first prizeAfrican tour.The modelis powered by We must now do a tour of the exhibitionwith his Messerschmidt 163B.And I thinktwo motors that weigh only 9oz., and each but before we startI would like to saythat my favourite in the non -flying categorydevelop s/ loth h.p. that Dorland Hall is particularly well suitedis the Mustang, by H. Marsden, of Graves- Altogether five model aircraft were being to an exhibition of this kind. end.It is complete with rockets under theflown round these three runways, but I only Forinstance,atthe ModelEngineerwings and has its engine bared for inspection. propose to deal with those thatI saw in Exhibition in the New Horticultural Hall Again we come to more flying models : flight. We cometothe De Havilland everything was, so to speak, laid out on athe flying boats of A. Webb, of Eltham-aVampire jet-propelled fighter 'plane.Much platter for you in a large expanse, with theSpencer - Dawson amphibian - and theresearch has been given by Squadron -leader effect that there was too much on view toSundaleena, which got a first prize for Mr.Peter Hunt, technical editor of the Afro= distract from the exhibit under considera-H. G. Bedness, of New Cross. modeller, to the production of this remark- tion at the moment. ablemodel. Itis,ofcourse,theonly At Dorland Hall the exhibits are arrangedFlying Demonstrations jet-propelled flying model.The jet -blower in corridors on the ground floor and on part Now we go up a staircase intoa large weighs 3oz. ;you can carry on from there ofthefirstfloor. Thus youprogresshall where there are three flying demonstra-on my well-known non -technicalBronto- logically from the time you enter one door tions.At the end where we enter theresaurus principle. in Lower Regent Street and come out atis a control tower, and roped off are three Lest you think thatI am leading you another next door to it. circularwoodenrunways onwhichtheup more garden paths than usual, I must Prize-winning Models On entering we have in a showcase on thelefttheprizeexhibitssentinfor competition from all over the country. First a Flying Wing in scarlet and natural wood by A. H. W. McBain, of Bedford. This modelispowered by an American Minijet. Another first prizeisthe Scylla tailless glider by A,J.Cockle, of Northampton,

A jet-propelled model of the D.H. Vampire. makeitclearthatthe Vampireatthe exhibition was electrically powered-which must be obvious even to the woman who bought a model rubber tyre for her dog. The third flying model was the Dorland high -wing cabin 'plane with tricycle under- carriage,As I understand it, the Dorland was put out for competition to aeromodellers, but the one which I saw in flight was an expert's job from a research department. Model Flying Boat Having satisfied ourselves about the three runways and what flies round and round them, we move soft. and look to our left down into a large pond on the lower floor. A flying model of the Vickers Viking. A gentleman in gum -bootsisjust putting who also got a special prize with a beautiful models take off and land after their tethereda model of a Sandringham flying boat on model of a Fairchild amphibian with a wing-round -a -poleflights.They are controlledto a floating catapult mechanism.It seems span of about sft. electrically from the control tower.Itis that, clever as these aeromodellers are, they In the same showcase Sgt. A. Weisbergalmost uncanny at first how the voice fromcan't get one of their dwarfs off water with- shows a model of his native Polish R.W.D.5.the control tower booms out through theout assistance.So Mr. E. J. Riding's -kin. It ispoweredbyar/rothh.p.two- loudspeaker -what a given model isabout to the footflying boat has to admit the stroke engine, and the hand -beaten cowling todo, and tosee thatparticular modelfact that Nature has provided water with issomething that has to be seento bemanoeuvre instantaneously. a so far impenetrable drag, and it therefore believed. has to plumb the depth of unreality by being Thus," Now ademonstrationofthecatapulted. Another first prize, by R. H. Smith, ofVickers Viking . . . the engines now start Wolverhampton, is a Mercury petrol model It fairly throws itself into the air, buzzes .. warming up . . taxis round the run-round the tether -pole and makes a perfect with a wing -span of about 6ft.It is a darkway ...takingoff onfullthrottle . . . andyellowhigh -wingmonoplane. landing on the water. blue undercarriage comes up . ..in normal flight It would be difficult to be fair to all the There isa modified Jersey Javelin with a . . throttles back for the glide to come stands, considering thatthere are17of 48in. wing -span.According to my infor-in . . . alittlebufst . . . undercarriage mationithasavertical corkscrew climbcomes down ... she is back on the runway."them, varying from Diesel Corner, display- and anti -spin fins.Anyway, it looks a very ing model diesel engines of less than tc.c., I need hardly remind readers thatthisto the well-known firm of AtlasMotors, fine model, and I hope one day to see itViking is the one that attracted great crowds do its " corkscrew." whose superb little engines have delighted I must explain that there are 12 differentat the Paris Aero Show. me almost from undergraduate days.We competitions, which embrace almost every Talking to -the man in the control tower,also have " Frog " and its plastic non -flying category of model from tailless to seaplanes Idiscoveredthatthemechanism which stuff,whichgoesunderthename of and flying boats,and a competition for modelretractsthe undercarriage so convincingly"Penguine."These arethe products of aircraft research equipment. One learns, forrelies on a small unit which played its partInternational Model Aircraft,Ltd.Itis instance, that in these days wind tunnelsin timing the German V.z.Iasked theclaimed forthe "Penguine " models that are as important in designing models as inexpert how these timing mechanisms weretheyatetheRolls-Royceofnon -flying designing full-scale aircraft. obtained, because, as far asI knew, onlymodels. two V.2s had failed to explode.His reply If I go on much longer I shall have to Non -flying Models was :" Afterall,they are only thesizementionallthestand -holders,which is Passing by some delightful model aircraftof a Leica film, andI imagine that they impossible.So I will content myself with engines, including a model of a Rolls-Roycemostly came back from Germany in men'ssaying that there were many interesting and Derwent I, we come round a corner to thepockets as souvenirs." new things for aeromodellers, and that I wat, solidscale models,i.e., non -flying models. The otherinterestingthingaboutthe pleased and surprisedtofind how many Among these I pick out a Mustang. a BoeingViking isthat, as you willrecall,itsbig necessities had reappeared on the market. 202 NEWNES PRACTICAL MECHANICS March, 1947 A Vertical EnlarAer Details of a Small, Inexpensive Apparatus Specially Designed for Enlarging 9.5 mm. Negatives to;-plate Dimensions

ByR.J. CHAMBERLAIN ALTHOUGHprimarilydesignedfor planistotryto pick up an old folding dealing with 9.5 mm. (about kin. by camera view -finder, or even the lens from in.) cine film, the enlarger about to a box camera view -finder.The lens must be described can be used for making en- be obtainedbeforeproceedingwiththe largementsfrom most miniaturesizesof construction of the enlarger, and while the negative, or small portions of regular sizes size should be tin. square, other sizes, such of negative.It makes -41-plate-size pictures as ;in. square or lin. square, can be utilised. (41in. by 34in.) which, incidentally, is a size selected because the dimensions are neither too small nor too large for most purposes. The Lamp House The amount of enlarging possible isnot The side elevation in Fig.rgives a clear confined to I --plate limits.If, for example, idea of the home-made enlarger.The ap- -1-plate enlargements are desirable, one has paratusisverysimply made up. Chief only to include a longer upright support rod requirements are some lin. deal, kin. and kin. to provide sufficient extension for the lamp plywood, a length of lin. diameter tubular house and itsnegative carrier and make a metal curtain rod and a few other odds and 61 -in. by 4.1in. print holder. ends. No condensing lens is needed nor an Itisratherunlikelythatenlargements opalising screen. The bulb of the electric beyond 1 -plate dimensions will be wanted. lamp --an opaltype-islargeenough to If so, the reader will have to extend the lamp cover the negative aperture completely with house base arm and bracket and also make a white illumination, thus dispensing with the largerbaseboard. The main ideabehind need for a screen. the print holders, of course,isthat these give a neat white edge to the prints, and The lamp house can be made first.The the main idea behind the enlarger, if built front and back pieces are cut from (prefer- to the dimensions stated, is the creation of ably) Bin. plywood, the side pieces being cut pictures which can be conveniently mounted fromin. stuff.Fretwood (plain thin wood) in an album. can be employed, of course, but unless this is well seasoned the heat from the lamp may Cine Film Enlargements cause a shrinkage.See Fig.2for shape and The enlargermakesexcellent" stills " sizes. from 9.5 mm. cine film. Assuming, then, The front and back shapes are attached on that you have in the past indulged in the the side pieces to be flush, using glue and hobby of home cinematography and possess * thin panelpins.Having donethat,the 9.5 mm. Pathescope film showing pictures lamp house base is cut tosize and shape of movie stars you wishtoenlarge and (see Fig. 3) from lin. wood 7iin. by Sin. preserve in an album, or, alternatively, pic- This, when fitted neatly to the bottom end of tures of members ofthe family taken on the housing, isaffixed with glue and nails. Kodak film witha cine camera, thiscan Prior to following this procedure, note the be easily done, even though you might not small slot cut in the arm end, and the dotted possess the negative films. The completed enlarger. lines running from it to the metal rod hole. On the other hand, you may want " stills " The slot is for a nut (belonging to the adjust- from standard size cinematograph film.In It must now be explained that the enlargerment screw) and a hole isdrilled through this case, however, you will only be ablediffers vastly from conventionaltypes.Itcentrallyforthe stemof the adjustment to deal with portions of the film picture, thismakes enlargements at comparatively shortscrew.This, in the writer's case, was part also applying to most other miniature sizesdistances.Ifa strip of 9.5 mm. cine filmofthe thumb -screw onatin.fretwork of film.Any size over V.P. (221 -in. by 'lin.)were projected on a screen by an ordinarycramp. means that only very small portions can beenlarger, the resultant magnification, at about dealt with, unless the images, such as heads,6ft., would be extremely small in comparison etc.,arefairlyminute,in which caseit with a 6ft. projection with the small, home-The Film Carrier might be possible to make portraits. made vertical type illustrated. The film carrier anditspackingpiece (Fig. 3) are cut from ;linplywood. Glue Lamp The Lens Used Holder Now a word about the most important item of the enlarger-its lens.Knowing the -)///11I) Light difficulty there is nowadays in buying lenses Trap of any description, the writer experimented Vents with the bi-convex magnifying lens in the I/ Height view -finder of a +-plate stand camera.This Adjustment lens measured sin. square and nearly lin. Lamp Screw thick.Under test, it gave excellent magni- House fication of small negative pictures, but only' /9" truly in the centre,the outer edges being somewhat distorted and tending to converge. Bracket This, however, was not surprising, since II the lens is not a proper anastigmat. Indeed, Film Carrier a single plano-convex lens, having asmall Aperture focal length, would project better pictures. A lens of this sort is to be found in cheap box cameras ; IIII Lens the focal length, however, is Adjustment usually about 5in.or thereabouts, whereas, Knot, to suit the enlarger, as designed, a tin. diam. lens, having alin. focal length, would be Print - Holder best. You will be wise to make use of a view- finderlens.If you own a-1-platestand camera, you could " borrow " the lens from 52; I Fig. 1.-Side elevation of the enlarger, givi ig its view -finder. The latteris seldom used, names of the various parts. although handy for outdoor snaps.Another Fig 2.-Details of the lamp house parts. March, 1947 NEWNES PRACTICAL MECHANICS 203 and nail the packing piece to the underside of 'The interior of the sleeve and lens holder the lamp house base arm, then attach the Packing should be darkened by applying black draW- carrier piece. T Piece ing ink with a pencil brush.This is advised The length of metal curtain rod should be I toreduce opaque" "andthe inserted through the arm holes to pull the lower end of the lamp house could also be pieces true during the assembly. Before similarlystained,includingthenegative withdrawing it, cut out (from -sin. wood) the carrier. bracket and washer shown in Fig. 2. Glue The lens holder sleeving is affixed directly on the washer, then attach the bracket, the beneath the negative carrier to be central lower end of the latter engaging with the with its aperture.In fact, the top end of notch cut in the former. the lens holder will penetrate into the car- As soon as the glue dries, the work is 44 - rier aperture by about kin.Consequently,. trimmed and glasspapered, then the height the sleeve is best fixed in position by push- adjustment screw fitted.The nut is held ing the holder fully into itto p:..sject for in its recess by a sheet metal disc which is centringthesleeveflange adequa.ely be- bent to shape and screwed on over it cen- neath the carrier. trally, as seen in the enlarged detail. The lens, which is shown in Fig. 4,is cleaned and pushed into itsholder.The 0 4' pieces E fit down on top ; these, too, should The Top and Vent Covers be stained black.If using a square lens-which may be unlikely-you should cut The lamp house top consists of a piece of out a sin. square from kin. plywood, with an kin. plywood and sin. deal attached together, inner ,'in. square hole for the lens; this will as depicted in Fig. 5.The hole in the *in. 111111,1114 preventthelensfrom moving sideways. piece isa ,in. in diam. A standard pendant Another idea is to " line " the bottom interior lamp -fitting fits into this hole, being secured sides of the lens holder with ?Tin. by kin. by its collar ring. Fig. 3.-Lamp house base, support and packingstrips of wood to surround the lens. The top, when fitted, is attached tempor- piece, with details of adjustment screw. This willalso applyiftestinga;in. arily with a couple of gin. by 6 roundhead diameter plano-convex lens.In many old screws, one being driven in at each side, cameras, the lens consists of three different preferably at 'the back and front.If the ply- 17-44=-1 -.-__2t_--..1" types, one being phino-convex.The other wood has a tendency to warp, use four two are invariably cemented together with screws. 1_ 1a T possibly, Canada balsam. These lenses The vent cover pieces (M and N) are cut O could be separated for test purposes in the from kin. plywood.Piece M screws over enlarger,but such interference is not advised piece N, and the screws should be kin. by 6 if it is desired to use the lenses again for roundheads, these being long enough to hold 4 camera work.

the vents over the ventilation holes in the The Negative Carrier lamp house front and back. It is at this stage you will need the nega- tive carrier in order to test the various lenses ei that may come your way.The carrier is Lens Holder and Sleeve made from a cleaned negative plate of The lens holder and sleeve parts are all plate size and a piece of kin. plywood the cut from kin. plywood.Great accuracy is same size, as seen in Fig. 6. needed in cutting the parts to their various Remove the emulsion from an old plate by shapes and sizes.A fretsaw handframe, or steeping it in hot, soapy water, then scrub- fretmachine, is definitely wanted, and a fine bing with a nail brush, finally rinsing and blade should be fitted, more especiallyif drying the glass.Unless the sharpness is plain kin. fretwood is used. - removed from the sheet of glass, fingers are The lens holder is made up from parts liable to be cut. Edges oan be easily dulled A, B, C, D, E and F (Fig. 4). When neatly by rubbing with an oilstone slip. cut out, including repeats of A and B, the A Lens A neat film " frame " aperture is cut in the pieces are glued to the B pieces, then in- kin. plywood as shown.The edges of the serted, unglued, upon piece C.The tenons wood should be rounded over at the front of the A pieces, of course, engage with theFig. 4.-Lensholder and sleeve partswith and sides only. The sheet of glass and wood mortises cut in C. The latter helps to hold details of lens used. is hinged together with a piece of insulation the work square until the glue sets. tape or other adhesive tape.It might be Meanwhile,preparethesleeveparts glue. When the glue sets, clean up theadvisable to " dust" the tape afterwards with G, H, J and K.You want a repeat of piecesleeving by glasspapering.The inside of (Continued on page 211) K only.Glue the J and H pieces to Kthe sleeve may need truing with a flat file to pieces, then attach the lot to piece G, usingremove spots of excess glue. The lens holder piece C is removed and to-- 3" the square tube fitted into the sleeve.If too tight a fit, reduce by glasspapering. A glass - //h papering cork, plus No. is grade glasspaper, ° is advised for this purpose.When made a Cleaned neat, smooth fit, glue piece C to the holder 34 Negative tubing, test again in the sleeve, then with- Plate draw to set.When set, the top of C is glass - papered to level the tenons, then disc D glued on centrally, with disc F added on D. Al Piece E is for packing the lens in the holder ---rape Hinge. and two pieces should be cut out ;these pieces should be a fairly tight fit. 31,

Lens Adjustment Knob 9 'ATI_ A helpful view of thecompletedlens - =71 IMtIII ifi-711'111 Tr holder and its sleeving is provided in Fig. 5. 7=0 The lens holder is adjusted by means of a small milled knob which drives into a hole - -L.- Holder Sleeve - Frame _ drilled in one side of the holder.Almost - Aperture any small size of knob can be employed, Lens Holder provided the threaded shank isnot more than kin. in length and kin. thick. A suit- Adjustment Knob able knob could be easily made from discs of Fig. 5.-Perspective view of lens holder and*in. plywood and a gin. long machine screw,Fig. 6.-Part sectional view of lamp house with sleeve, with details of lamp house top and ventthe nut serving to "bind" the discs to thefront removed to show interior, with negative Covers. screw. carrier parts. 204 NEWNES PRACTICAL MECHANICS March, 1947 A Remote -controlledlin. Scale Model Tank

Constructional Detailsofa Scale Model 'Churchill" Tank

By PHILLIPF. DODD

(Concluded front page 168, February issus)

finished withsquadron,divisionaland recognition markings in the correct colours. Its official " W.D. number " is T13745, this being the day, month and year in which it was completed. Operating Notes The case in which the model istrans- portedis divided intotwo compartments. Thelargerandright-handonehouses themodelitself ;the smallerandleft- hand one contains the controlpanel, the The model tank travelling over an obstacle. trickle charger and itslead to the mains, and theseven -corecablecomplete with IN,,order to solve the chain -drive problem, The present model has, however, given seven -pin plug.(Fig. so.) A short length of the designer endeavoured to discover athe designer and his friends many hours offlex carries a three -pin plug at one end and a manufacturer who produced half -inchenjoyment and never failsto amuse asit pair of alligator clips at the other. pitch,straight -sidedlinks,and eventuallythreads its way round chair and table legs, After unlocking and opening the right- decided to sweat small brass strips, each :in.as it creeps across a loin. gorge and nego-hand lid and removing the spare parts tray, high and -; in. long, on to the side of each link tiates 32in. high vertical obstacles. the model islifted out and placed on the so that the bogie wheels would run smoothly The whole ispainted khaki green andfloor, making sure that the bogie wheels are over them instead of the chain links.There running correctly on the tracks.Do not would have been 376 pieces each to be cut attempt to push the model along by hand, in.highandlin.long,roughcorners and itis recommended that the surface on smoothed, stepped so asto clearitsover- which the model is operatedishard and lapping neighbour and sweated to the hard smooth, such as linoleum or a thin carpet. steel pivots of the bicycle chain.This was abandoned as being very tedious and not /6 P81.- altogethersatisfactory. The ideal method was to designatracklink which would 7 r -4- resemble as closely aspossible those em- '§2 ployed on the prototype. A pattern was cut in ebonite, Fig.8, and many weeks were spent -in attempting to procure someone to cast 25o of these links.One firm would makenotless than 10,000for £40, which was reasonable enough for that quan- tity, but when only 25o were required this y 8 appeared to be rather expensive.Finally it 52 w was decided to manufacture them at home. 32-F232 3I.b2 A mould was built up of mild steel sheet and Machineorfileoffin platesof varying thicknesses, Fig. 9, and accordance withdotted scrap silicon aluminium headers and risers lines.Drill to centres. were purchased from a foundry.This alloy is easy to melt, flows readily, and does not show an easy tendency to oxidise in the molten state.It is comparatively strong and quite strong enough for the job in hand. J After casting, the headers were removed, and each link was drilled, filed and pinned to its neighbour. A considerable amount of filing was necessary owing to the primitive mould. The track pins were made from nails with the heads removed and cut to length.They were bent slightly before inserting into the link holes, and were thus held rigidlyin place.From casting to finishing each link took15 minutes ;there are 94 links per track. The mould was made in five days and casting took a fortnight.Again, time was well spent, and the track "looks right." Itis hoped to build another model with two motors, each motor driving one track, Viewin direction and steering being effected by the difference in speed of the motors, which will be con- trolled through two rheostats. Fig. 8.-Details of the track links. March, 1947 NEWNES PRACTICAL MECHANICS 205 tive and positive marked clips at the othel end of the flex should then be attached to the appropriate terminals cn a 12v. battery. Ammeter Resistance Direction Slider This is very important.The slider on the Control trickle charger must now be moved until it isas near as possible to the front of the box.Take the trickle charger lead and plug into the mains.Switch on.A humming sound should issue from the charger. Switch RN. on the battery by moving the switch on the switch -plug to the up position.This switch is provided solely for the purpose of switch- L.H. ing the battery on and off.Move the slider until the ammeter is showing a charge of not more than 2 amps. The model is now ready for operation. 7Core Cab Mains battery Lead Plug The direction controlleveris moved to " F " (forwards) or to " R " (reverse) accord- Fig. to.-The case for transporting the model tank ;showing the control panel, etc. ing to the direction in which itisdesired that the model should travel.A click will be heard in the model when the control lever /. Turret Motor is moved to " ; this is an indication that 2. L H Steering Solenoid the reverse switch solenoid is operating. The 3. R.H. Steering Solenoid 4Reverse Switch Solenoid model must be allowed to come to rest before Terminals (a)8 (61 5. Main Motor changing from " F " to " R " or vice versa, operate in parallel, 6. Spare otherwise damage to the motor may result. (a) contacting first, 7. Earth

Attach appropriate leads of 7 core Steering and Turret Traverse R.N. cable to these terminals located To steer the model . . . utilise the two inside the control compartment, white press -buttons marked " left steering " and " right steering."A click will be heard from the model when eitherof theseis Transformer....a000eo Mains pressed. Thisisan indicationthatthe L.1-1, Rectifier steering solenoid is working.Continually tap Output at the press -button if no click is heard. 12v, 2A. . . These leads have To traverse the turret switch off the alligator clips for battery and move the trickle charger slider connection to battery towards the front of the box.Press the buttonmarked" turrettraverse." The Switch turret will revolve slowly.To increase the Plug rate of traverse move the slider on the trickle 0 0 0 charger.(The turret may be traversed when 2 3 4 5 6 7 the model is moving, without switching off thebattery.) Beforeswitchingonthe 1-10/41MIM., battery again, return the slider to the front Fig. t r.-Diagram of connections for the control panel. of the box . . . switch on the battery.. . and then move slider -until the ammeter reads A carpet which has a thick pile is inclinedrear of the model.Before the next opera-a 2 -amp. charge.On no account must the to catch the ends of the track links, withtion make certain that the direction controlmodel be operated direct from the trickle serious results to both carpet and track. leverisoppositetheletter" S "(stop). charger, that is, when the battery is switched Uncoil the seven -core cable and attach theTake the short length of flex and insert the off.Spare fuse wire (5 amp.) is carried in seven -pin plug to the near -side of the model,three -pin plug into the switch -plug, seeingthe spare parts tray.Note.-The model may the offset pin in the plug being towards thethat this switch is down, i.e., off ;the nega-be operated from the battery alone.

f.t T6 32t

-.1)61 21"n Ejector screws nor Breathers snow,,,

Ejector screws Breather '2 Ejector screws SECTION ON SECTIOA! ON

gall. /la AIL, Ilk 1111 Iiil IM EMI 'RP" 4111 Mtn Milt,i olrA .1.1,VOLIMPIANAPC., VWWW \WM,: VfilliD111111I&

SectionOnAA Sec:'ion on B3 Fig. 9.-Details of the sheet steel track link mould and die plate.Brass screws are used and all threads are 5/32in.Whit. 206 NEWNES PRACTICAL MECHANICS March, 1947 Observations Interesting Facts About Everyday Topics Black Diamonds not therefore come to a focus together.It has EVERYONE knows, which meansthat By Prof.A. M. LOW been found that nearly every creature in the no one bothers, that Nature took one world that can see has some form of correc- littlesubatomicparticle and madedig them up.Nor are they big enough totion, so we should not be too proud of our everything.Including you.And the won-be of service. skill.Even a moth can see by lights invisible derful thing is that all these substances have I cannot help feeling, although I hate toto us, and many species can be attracted by taken millions of years to manufacture. Notpoint a moral, that many things, such asinvisible light.Half the work of science is that time may mean anything, any more thancoal and steel, are in truth more importantin providing ourselves with means of obser- a dream.Oil, for instance, was made mil-than gold and diamonds.Itis only myvationbetterthanthatof our unaided lionsof years ago from fish,vegetation,opinion! Which would the world be bestsenses. anything, anditdoes not even take verywithout ? long to turn it into the product useful for Did You Drop It the roadster or the aircraft tank. The Dog's Warning So many people were interested to know But the queer pointI want to make is As you drive homeat night, you willwhy cigarettesfell with the ash uppermost that these substances do notallcombinehave noticed on a wet day that reflectedthat I think it my duty to take up the much unlessthey have somebody or somethinglightstravel up house wallsinfrontofmore important question of bread and but- to marry " them. These marryingyou.It always puzzled me until I noticedter. Doesit,infact,alwaysfallbutter " people " arecalledcatalysts, being sub-thatit was the shortening angle betweenside down ? stances which produce chemical changes inheadlights and water on the road.But what Some years ago a large number of experi- others, but do not themselves alter.Like Ilikearethe glowing eyesof animals,ments were made on amusing things of this a parson who presumably alters the partici-which seem -betterthan most rearlightskind, and it was discovered that butter, being pants,butisnot, wetrust, changed inon the road. heavier than the remaining part of the slice, himself. This is due to a high degree of reflectionacted like a weight tied to a piece of paper. Take, shall we say, a piece of coal whichat the back of the curtain of the dog's eye.The butter on the average fell downwards. burns in air.If this coal is dried or des-Human beings have an iris diaphragm whichYou can make another amusing little experi- iccated very thoroughly it can be made redopens and shuts to regulate the amount ofment for yourselves in this way by putting a hot without burning atall. Allow in thelight which passes through to the sensitivesmall piece of tissue paper on top of a coin faintest trace of water and the coal flashesretina.When this action is not very quickand dropping iton the table coin down- off into flame. Now this is not a true cataly-yousufferfromlackof accommodation, wards.The paper and the coin hit earth turnsinto sticaction, because the water hence you must get used to light, and itis together simply becauseallbodies fallat steam and the coal might absorb some ofoften a good plan to shut one eye whenthe same speed, and it is only air resistance this oxygen leaving hydrogen to run a gaspassing acar.If the other man's car iswhich normallyprevents the paper from engine, as in a producer plant.Or the coalstationary, winking in this way may, how-falling as fast as a piece of lead.When put might partly burn and leave carbon mon-ever, be misconstrued if seen ! together the coin breaks the way and the oxide,ashappensin many ofthegas The dog has its frontal lens so shapedslight vacuum at its back holds the paper generators which we have been using onas to throw back the light from the colouredfirmly inposition. the back of our carsin England to savepart into your eyes petrol. andthecolour is Fancy having to take the gas works withmerely due to the you ! No wonder thedriveriscalled afactthatallother chauffeur.Examples of catalysts are somecolours givenout of the nickels and their compounds whichby your headlamps are used when adding hydrogen tooil toareabsorbed,with make hydrogenatedoil. Anotheristhe the exception of the platinum wirewhich, when placedina colour you see. gas jet, becomes so hot that the gas ignites. Cheap spectacles This principle was used toindicate an are always being escape of gas in submarines, or mines, andintroduced and when at one time was replacing the canaries andthey are very bad white mice which gave the first signs longthey are like com- before they could be detected by men in thepound lenses manu- same atmosphere. factured most poorly. These detectors were clever.To prevent Look through a heat affecting them as well as gas, the plati-simple lens and you num wire was stretched against a glass wirewill see coloured which expands atthe same rate.Only aringsroundt h e difference in temperature between platinumedge, rather like and glass could sound the alarm. the refracted colours you will observe Dirty Diamonds from a chandelier or the edge ofa Some will have wondered why I seem tob ev elle d looking - interchange the word " coal " with that of glass. " diamond."There is a good reason. Unless the coal contains hundreds of medicaments The edge of the and, like the sea, practically everything inmirror is like a the world from which we now get oursectionof alens. civilised blessings,it Itbreaksupthe is no more than purelightintoits com- carbon.Charcoal is another form. And soponentcolours. is the diamond, which happens to be crystal-Now, our eyes have lised carbon. bad lenses,but we Nature made these diamonds by greath a v elearnedto heat and pressure.If you take a piece of correct the effect in The Meco Moore Mechanical Coal Cutter and Loader enables sixmen steel containing carbon, melt itin an arc,our brain. Camera to do the work of 20, and can cut a ton of coal a minute.Under and allow the drops tofallinto a basinmakers have to usefavourable conditions the machine will cut, break and deliveron an of water, a very mild imitation of nature isachromatic lensesif endless -band conveyor up to 500 tons in one seven -hour shift. Twenty given.Upon dissolving the solidified drops,theydo not want of these " Iron Men" are at work in the pit of the Clipstone Colliery, tiny diamonds remain behind.They are, introuble, simply be- Chesterfield, and many other collieries await delivery. These machines - fact, allotropic modifications of carbon, butcause e a c h colour will play a big part in solving the manpower problem of the mines. my duty is to warn you that itcostsfarhasits own wave- The illustration shows one of the Meco Moore machines being operated more to make them in this fashion than tolength, and they do in the pit of the Clipstone Colliery,- Chesterfield. March, 1947 NEWNES PRACTICAL MECHANICS 207 The Volkswagen -The People's Car The Much-discussed German Small Car By " TECHNICUS

WHAT is the people's car, or Volkswagen,while the rear wheels employ torsion rods. Capacity :1,131 c.c. of Germany, so much debated inHydraulic shock absorbers are also incor- Firing order : 1-4-3-2. GreatBritain,andoverwhichporated,single -actingtype onthefront Valve clearance : cold-inlet :.006in. questions are being raised in official circles ?wheels and rear, to prevent rebound. outlet : .008in. Thereisnothing unusualinitshistory, The arrangement of the platform referred Carburettor : downdraft. for the German Government asked for a cheap,to above, axles and gearbox,is shown in Battery : 6 volt, 75 amp. -hr. small car to be designed a few years beforeskeleton form in Fig. i.The body is bolted to Coil ignition. the war.The Volkswagen was the result.the platform and mounted on rubber. The de- Fuel consumption : 35-40 m.p.g. Its, development was typically German. Asign of the body gives full room for four adults, Fuel tank capacity : 91 gals. verylarge sum was voted thecountry'swith luggage room for two average suitcases Crankcase capacity :I gal. leading automobiledesigner to undertakebehind the back seat.Wheels are pressed Although a four-stroke engine, its normal intensive research in design and manufacture,steel, as are the transmission and gear housings,running sound inclines one to the view that so that a small car could be made available toand,whereverpossible,boltshavebeenit is a two-stroke, and it is not so quiet as the the pockets of the working classes in Germany.dispensed with in favour of welding. modern orthodox four -cylinder engine. A suitable design having been decided Headlamps areintegralwiththefront upon, the site for mass production was selected,wings, while the bonnet cover is in one press-Miscellaneous Features at Wolfsburg, near Brunswick.But the waring,being hinged along thelineof the The lifting jack isfitted, when required, interrupted the project just when the workswindscreen. There are two side windows,into a tube permanently fitted to the chassis was to go into production, and it was left toentrytothecar being through oneplatform, and isoperated with the wheel the Allies, when they entered the Reich, todoorof generous size, on each side.wrench, thus economising in one tool.The rehabilitate the alreadi-damaged works and An unusual point is the heating of therear axle is of the half -axle pattern, while to produce the firstbatch of Volkswagen. the front axle is made up of a twin -beam centrelock. Pr.essed steel platform gearbox Torsion leaf spring.

Fig. i.-(Left) Showing the arrangement ofthe Torsion spring platform, axles and gearbox, in skeleton form. stop (Rubber) 2.-(Above) Showing the torsion springs, Tubular steel backbone.)Fig.which are held by the centre lock. It is interesting to note that production atinterior, and of the windscreen, from hotassembly, the fore end of the tubular back- present, with only part of the works repaired,air ducts, heat being derived from the exhaustbone beingcarriedbetweenthebeams. is over 2,000carsa month. manifold.Here again pressing and weldingThrough the latter, which are hollow steel are used exclusively, the hot air ducts fortubes, run the torsion spring leaves held by Fresh Ideas the windscreen being small louvres situatedcentre locks, as shown in Fig. 2. It would be doing car manufacturers inin the bottom corners of the windscreen. The silencer isarranged parallel to the various countries of the world an injustice rear axle, instead of the more usual practice to suggest that the Volkswagen is revolutionaryEngine of thesilencer running lengthways.This or embodies new ideas. Whatitdoes An air-cooled, four -cylinderhorizontallymakes for compactness, and enables all of the unquestionably reveal is a fresh outlook onopposed . engine is mounted in the rear, on apower unit and accessories to be sited behind car construction, with originality applied atthree-point rubber mounting.There is onethe rear seat. everyturn. Thesomewhathideboundcylinder head for two cylinders, the pistons As might be anticipated in a rear-engined notions of the British manufacturer have beenbeing of light alloy. The crankshaft is of thevehicle, the gearbox is operated through a dispensed with and a fresh start made, fromfour -bearing type, possessing high rigidityshaft which runs through the tubular back- the wheel nuts to the windscreen wipers.Theowing to its short length.Cooling is effectedbone. Gearbox and universal are housed multitude of bits and pieces which spreadby means of a fan, which delivers air overnextto one another, under the luggage over British cars like a rash are conspicuouslythe finned, cylinder castings at 500 litres acompartment referred to above.The petrol absent, giving a clean appearance both insidesecond.The fan is driven by a belt from thetankissituated under the front bonnet, and out. generator pulley, and servesalsotocooltogetherwiththesparewheel,holding In discussing this small car it is essentialthe engine oil, which is circulated throughsufficient for about 35o miles, a spare tank snot to lose sight of the fact that it was designeda radiator -type cooler. being incorporated. There are two rear "with a very low price in view, the selling price Push -rod overhead valves are mounted onlights, and headlamps can be dipped by reported to be about £40.That may havethe light -alloy cylinder castings, fuel beingmeans of the usual foot switch. been possible, but the intervening rise in thefed fromasingle carburettor of standard cost of living has taken the cost of manufacturedesign.Force-feed oil lubrication is assistedPerformance up to almost twice that value.The lowwhen the oil is cold and viscous by a valve Ifseveralinterestingideashave been sellingprice madeitnecessaryforthewhich bypasses the oil cooler during a coldincorporated in the Volkswagen, no attempt designer and his staff to plan the car not onlystart.An indicator lamp on the dashboardhas been made by the designer to give the in relation to the owner's needs but also withlights up when the oil pressure has fallencar a super performance.Indeed, as it was an eye to production, both cheaply and on abelow a safe minimum, due to a defect in theexpressly designed as an all-purpose people's very large scale. feed. A simple strainer in the sump is con-car, itis unlikely that a freak performance sidered to be sufficient to keep the engine oilwould have been sought. General Construction clean, while a small air filter on the carburettor The following are the recommended speeds A feature of the Volkswagen isthe useintake ensures that dust does not pass intoin the various gears : throughout of pressedsteel and welding.the cylinders with the air. 1st speed (crash) : 13 m.p.h. (ratio, I : 3.6o) ; The body rests on a pressed steel platform, The following are details of the engine. znd speed (crash) : 24 m.p.h. (ratio, I : 2.07) ; andisthereforeunstressed. A tubular Rating : 25 b.h.p. at 3,300 r.p.m. 3rd speed (silent) : 4o M.p.h. (ratio, r : 1.25); backbone is forked at the rear to carry the Compression :5.8: t. 4th speed (silent) : 62 m.p.h. (ratio, 1: 0.8). engine.Wheels are independently sprung, Bore : 75 mm. The mechanical brakes, hand and foot, will those in the front using torsional leaf springs, Stroke : 64 mm, pull up the vehicle in approximately 34ft. 208 NEWNES PRACTICAL MECHANICS March, 1947 at 25 m.p.h. on a dry surface.The high ratio of the 1st gear, coupled with a final drive ratio of r : 4.43, gives this little car goodhill -climbing ability,it being able to negotiate gradients up t.o1 in 3. The length of r3ft. 4in.is accompanied by a turning circle of 33ft.The ground clearance is 8in., and overall width 5ft. tin., with a height of 5ft. tin. also.The unladen - weight of the people's car is 1,600lb., indi- cating that it is truly a light car.

General Criterion The vehicle handles well on the road and is easy to drive over long distances.There are no frills and furbelows, and for driver and passenger comfort is adequately provided with- out the many touches given to higher -priced cars as selling points.Itis competent in performance,haspleasingifsomewhat dumpy lines, as will be seen in Fig. 3, and would be well worth Eroo, for which price it could be retailed in Britain, were production costs normal and material supplies up to pre-war standard. In considering the Volkswagen one must remember that it is being made from limited materials of inferior quality.Thus, castings, where employed, are not up to standard on Fig. 3.-The pleasing appearance of the Volkswagen. quality.Soft metals used in the front axle assembly lead to an increased rate of wear.it is evident that a car in any driver's handsproved if British car manufacturers can graft Cylinder block castings being of distinctlycannot be expected to yield the life of thatsome of the novel ideas of this German car wartime quality cannot be expected to standwhich is owner -driven.At present opinionon to the good quality of British small cars. up to the high speeds demanded of the car,is derived mainly from the experience of a It will be interesting to see if " expense the autobahns helping in this direction.Inlarge number of non -owner -drivers, some ofof dies," " the pressure of export demands " effect, one is confronted in this little vehiclewhose object is to get from one place to theandotherexplanationswillpreventthe with the combined disadvantages of low price other as quickly, or as relentlessly, as possible.adoption of some of the people's -car -notions and low quality materials. It would be unfair to judge the capabilitiesin Britain. A real people's car, which can be If one remembers the above, the perform-of this little car before it has been in themade for modest pockets, is long overdue. ance of the Volkswagen, in relation to its cost, hands of a large number of owner -drivers, andIt need have no chromium plate, gadgets and is very good. There is much to learn from it,before reasonable -quality materials are againthe many superfluities that go to put up the and it would be interesting to imagine howavailable in Germany for mass production.cost, albeit against the will of the manufac- Britishsmallcars would stand up toits The author of thisarticlehas driven aturer. A simple pressed -steel frame and body, competition, given normal material supplies. Volkswagen for three thousand miles, and isan ingenious use of modern synthetic resins Another factor which militates against it isof the opinion that, given adequate care, theand a little courage are the ingredients for that it has not received a trial at the hands car should prove a useful addition to the smallthis much -wanted car.Which manufacturer of owner -drivers. To any experienced motorist car market. Above all, its value will have beenwill show the way ?

This English method of measuring lengths and surfaces is less logical-and less useful, a too-than the Metric System. But itre- Mathematicsas Pastime -3 minds you of a deal of our history. Measuring Lengths and Surfaces By W. J. WESTON You get a great circle of the earth when- ever you slice sheer through the centre of the earth: the Equator is one of an infinite number of such great circles.Any other YOU remember how-Horatius having51 yards also became a convenient device forslicing gives an ever diminishing circle.The kept the bridge in the brave days ofsetting it out.The modern chain for land -navigatorseeks, whenever possible, tosail old-the City Fathers gave him, ofsurveying hasitsroo links,so that eachalong this great circle.Thereby he covers the cornland, " as much as ten strong oxen link is almost 8 inches. the shortest distance beween two points. canplough from morn tonight."Very The acre became our unit for comparing Think, for instance, of the ancient quip, likely your own forefather hadhisland recurring ever in varied guise. You, allotted in like manner. He drove his oxen Furrow- Long (Furlong of 220yds) perhaps, like so many of us, were a furrow -long (or furlong) as many times as deludedatfirst. Hereisthe he could from dawn to dusk; and, being a modern version. stout-hearted worker, he managed a width TheUnited A CRE. States has, or will have, a watching of about one -tenth of the furrow -long. There post at the North Pole :a patrol was his field, his acre (to use the word that from the post goes four miles due we still find in " God's acre," and in place- Chain of south, then five miles due east : the names like " Long Acre ").Later, when we 22Yards. patrol then returns to the post by becamefamiliarwiththeRoman miles Dimensions of an acre. the shortest route. How long is the (millia, or thousands of double paces), the route ?Of course, there are only furlong became standardised into one -eighthmedium surfaces :" Now would I give afour miles on the great circle from the post ; of a mile ; and the yard -stick, to ensure fair-thousand furlongs ofseafor an acre offor, however far east or west the patrol goes, ness, came into being.These miles varied,barren ground," declaredatempest -tossedit remains at constant distance from its base. and still vary.In the British Empire andand poor sailor.The square mile for larger the United States, however, the legal milesurfaces, the square yard for smaller, takes (To be continued) is now one of 1,76o yards. [For the nauticalthe place of the acre. mile (which sailors call a " knot "), though Like the furlong, once varying with man calculated equal to one, minute of a greatand ox and soil, the fathom, the length of the REFRESHER COURSE circleof theearth, the British Admiraltyoutstretched arms, is now standardised into IN fixes the length of 6,o8o feet.]Twenty-twotvAS yards; the foot, no longer changing with lengths of the yard -stick extended along thethe Chancellor's,is standardised into one- MATHEMATICS base of the ploughed land ; and this lengththird of the yard.The inch was always a By F. J. CAMM. developed into our cricket -pitch. A chain oftwelfth part, and we restrictit now to the 22 yards set out this base, and a pole oftwelfth part of a foot. 8/6, by post 9/- March, 1947 NEWNES PRACTICAL MECHANICS 209 THE WORLD OF MODELS Models at the Shipwrights' Exhibition: A Fine Scale Model of a Modern Distillery By "MOTILUS" Wigham Richardson, Ltd., as examples their warship construction for the Admiralty. Messrs. Bassett-Lowke, Ltd., had a small exhibit fromtheirShips Models Depart- ment, which included a model tug boat, one of the new working models they are placing on the market.This model tug boat, which was on view atthe Britain Can Make It Exhibition,isan up-to-date design of the steam tug,electrically operated, the motor being their standard " Marine " type.The

Fig. 1.-A fine model of the " Queen Mary " built to a scale of Soft. to tin.(Photo by the Cheltenham Photographic Company, Ltd.) IHAVE no doubt that many of our readers, especiallythoseinterestedinhigh- classship modelling,paidavisitto theShipwrights'Exhibition, organised by the Worshipful Company ofShipwrights, and heldatthe two Royal Horticultural Society's Halls, Westminster, from January 28th to February 8th. Quite a number of the models displayed were made by Messrs. Bassett-Lowke, Ltd., Northampton, and as I had the opportunity of seeing some of these models before they left the works,I can say that they were typicalof thesplendid workmanship for which this firm has been famous for many years. Over a period of more than 12 months, skilled craftsmen have been busily engaged on a series of waterline models for the firm of Messrs. Wm. Harvie and Co., Ltd., whose Fig. 2.-Model tugboat by Bassett-Lowke, Ltd.It is 25in. long and is driven by a smar navigation lights have been famous electric motor. A dry battery or accumulator provides the current. throughouttheshipping world for many years.This collection, all made to a scale ofsoft.totin.,or1 /600thactualsize, Of the traditional type of scale models ofwhole of the superstructure can be removed represents a selection of ships, both Britishships, that is the full hull glass case model, to gain access to the electric motor, which and foreign, which have beenfittedwiththerewere two veryexcellentpiecesof is driven by standard flashlatinp batteries or the Harvie navigation lights.Such a wideworkmanship in H.M.S. Vindex and H.M.S.an accumulator. This model,ifavailable, range of waterline models naturally attractedAnson. Both these_ models were made toshould be very popular during the coming great attention. the order of Messrs.Swan, Hunter and s u min er.

Fig. 3.-Part of sectional model of a Scotch Whisky Distillery, built by Bassett-Lowke, Ltd., to the order of the Scotch Whisky Association.The illustration shows, from right to left :(t) The lean-to Barley Arrival Shed ;(2) The cleaning plant ;(3) Maltings ;(4) Kiln ; (5) The Mill Room ; (6) Mash House. 210 NEWNES PRACTICAL MECHANICS March, 1947 -. - Altogether,theShipwrights' Exhibitionfind a ready purchaser at their ports of call. isfirst brought by lorries to be prpcessed, was an outstanding innovation in exhibitionsAlthough there are Many eitietts with thisand at the'right-hand side of the first picture in thiscountry, and was asurvey ofall clever idea, which has been explained in(Fig. 3) the lean -To " Barley Arrival" shed productions relatingto the nautical world,many publications, itisstill a problem tois seen.The second department, the Clean- covering sectional models of war and com-some who practisethe hObby of modeling Room, is where the dustisextracted mercial marinecraft,turbine,steam andmaking, andI am surethe shipin before it is passed into the maltings.In this oil machinery, auxiliary machinery, etc.Inbottle " will always have a fascination fordepartment the barleyis kept at a certain addition to the usual exhibits, there was athose who love a novelty. temperature, is partially " grown " for seven special feature inthe form of aseriesof days, being continually turned over to aid papers and films which dealt with all aspectsModel of a Modern Distillery the process, and then is passed to the kiln, ofships,theirdesign,constructionand In theDecember issue,reference waswhere it is dried.In Room No. 5, the Mill operation. Other papersdealingwith made to a scenic scale model of a ScotchRoom, the barley is ground up to what is various subjects relative to the shipbuildingmalt whisky distillery, and an illustrationknownas" Draff." The draffisthen, and marine engineering professions werewas given of the typical Highland setting inpassed into thenext room, which isthe of great interest to the younger generation, Scotland of a modern distillery.I aria nowMash House.This department, whichis as theydealtcomprehensivelywiththe able to give some illustrations and particu-shown at the extreme left in Fig. 3, and at opportunities ofcareers presented by thelars of a detailed model showing the whole theright-handsideofFig.4,iswhere industry. of the processes of whisky distillation.Thisliquid isfirst added to the ground barley, model, representingmonths ofskilled and inthe next room, the Draff Drying Northampton Society of Model Engineerscraftsmanship, was madespeciallytotheHouse, the liquor is separated from the draff. By the way, I hear that the Northamptonorder of the Scotch Whisky Association soThe draff, a by-product of the whisky, is Society of Model Engineers, under the ablethat the general public could visualise thethen dried and taken back tothe farms, secretaryship of Mr. W. A. Wells, of theprocesses which have to be gone throughwhere itis used on the land as a fertiliser. Guest House, Moulton, Northampton, are before the famous and popular spiritis The liquor, which is now whisky in a very becoming increasingly active, and plans are ready for sale.Covering about 14 differentrough state, is passed on to Room No. 8, the being discussed for a " get-together," withdepartments, and made to a scale of Bin. to" Tun Room," where it is again fermented. a view to increasing the membership, and 'ft.,themodelmeasuresapproximatelyNext, the liquoris passed on to theStill also to discuss the prospects of holding an 7ft. 6in. by 4ft. House.The illustration, Fig. 5, shows two exhibition of members' work in the autumn The model shows clearly how the barleystills.At the first distillation the liquoris of1947. In a town so well known for model making, there should be room for a very active model society,especiallyasI understandthatthreeModelEngineer Exhibition Cups are held by amateur model makers in Northampton.Model making is now enteringintothe " arts and crafts " societies of various Northampton firms, and atarecent exhibition of work done by employees of Messrs. Padmore and Barnes, the well-known shoe manufacturers, a prize was won by Mr. C. Robinson for his model of a ship in a bottle.As all model makers know,thiswas afavouritepastimeof seamen in their short leisure hours on the old " windjammers," when theycould always

Fig. 4.-The second portionof theScotch Whisky Distillery model, showing :(6) The Mash House ;(7) The Draff Drying House, and (8) Tun Room.

passed through the condensers on the left- hand side of the picture, after which itis cooled, tested for strength, and passed back throughfurtherdistillationprocessesto purify. From that time, that is after it leaves the stills,itis under Excise lock and key, and under the supervision of the Resident Excise Officer.After leaving thestills,it goes to the warehouse, where it is put into casks for storage. The whole model shows clearly that the handling of the grain right through to the final production of the whisky is by auto- matic conveyor and pumping systems, and is not touched by hand at all, except in the maltings.

On View in Edinburgh Specially transported by road to Scotland, this wonderful model is now in the Royal Scottish Museum at Edinburgh. After it has been in Edinburgh for some time, the whisky distillery model will be used for exhibitions in different parts of England.It will prob- ably then be sent overseas to bring to the notice of the world the complicated processes involved in the production of one of Britain's Fig. 5.-The Still House, showing the beautifully detailed craftsmanship of the whole of most famous, and valuable, exports-Scotch the model distillery. whisky March, 1947 NEWNES PRACTICAL MECHANICS 211

binding as this in turn ekerts a slight pressure on the spring and gives a completely water- Letters from Readers tightjoint ; (d) To finish off slit the tape through the " Are You Wrong ? " (i)The roadspringswere completelycentre for a few inches, knot, and tie as you SIR,-In the January issue of PRACTICALcleaned off and were then covered with oldwould a bandage. MECHANICS, Prof. A. M. Low statesengine oil, the oil being well brushed in I tried this idea out many months ago and in his " Science Notes " :" The sun does notbetween the leaves. my local garage suggested that some rusting put out the fire but makes it more difficult for (2) An ordinary lubricating castrol greasewould occur.Inasmuch as the plastic tape you tosee,"etc.Ido not quite agree.was then generously appliedallover. is completely impervious to the action of oils The sun gives heat and heat causes expansion. (3) The spring was then bound with theor moisture, I was not convinced that this This expansion of the air surrounding a fireplastic tape, as follows : was so, but feeling there may be some reason causes the oxygen to become rarefied and as the for the suggestion last week -end I stripped the fire is dependent on the oxygen to support covering with a sharp knife, and, as I expected, its combustion it consequently burns slower. found the springs in perfect condition.There -THOMAS A. MEADE (Cavan, Eire). was no sign of water penetration or rust, and [Utter nonsense!-ED.] the clean grease was still around the spring. Electric Flash Light -E. N. CRUMP (London, S.W.). SIR,-I noted the answer to Mr. Newman's Register of Model Engineering Societies query re the door bell and lamp in the SIR,-With reference to the letter from Mr. January issue.In the same issue, there was Pinnock,oftheS.M.E.E.,which an advertisement for Varley Thermal Delay appeared in a recent issue of your journal, Switches, and it occurred to me that a simpler concerning the compilation of a register of solution to the problem could be found by club data for the whole of the country, I using one of these,or something based would like to draw the attention of your on that principle.I therefore enclose two readers to'the fact that information relating to possible circuits which might be of some use. Thermo Switch Normally Closed clubs in the north can be furnished by myself, The lamp in each case is connected across P- Bell Push. C - Small C/ondens.er: as secretary of the governing body for the the bell magnets with the bell adjusted to give T- Thermo Switch Heater & Contacts. north of England. a slow beat. The dataatpresent availableisbeing A.A circuit for a thermal switch with the extended to embrace all non-affiliated clubs, contacts normally closed.The contacts on as it is considered that the association will be opening would break the relaycircuit. better able to be of service to model engineers B.A circuit for a thermal switch with the contacts normally open. generally, and particularly those who will be A small resistance or a flash -lamp bulb is visitingtheforthcomingexhibitionin placed in series with the relay.The thermal Manchester.-A. F. Duclarr, Hon. Secretary, switch contacts on closing bypass the relay, The Northern Association of Model Engineers, the resistance or bulb preventing a short- 545, Bowring Park Avenue, Liverpool, 16. circuit. Waterproofing Processes If the circuit was fed from a transformer, SIR, -We have received a large number of the connection marked X could be taken to a inquiries in regard to the reproofing, highertappingifnecessary.-B. TOON rubberising or otherwise making waterproof (Stamford). ex -service flying suits, the writers of which, ThermoSwitchNormally Open in most cases, refer to your paper, NEWNES A Tip for Motorists P- Resistance or Flash/amp Bulb. IR,-I am sure many readerswillbe PRACTICAL MECHANICS, as being the source Circuit diagrams for a flash -light system, using afrom which they have obtained our name 1.3 interested in the method which I have adopted for keeping the road springs on my car thermal delay switch.(B. Toon.) and address as a firm capable of carrying out working in a clean mixture of oil and grease.' this work. Iobtained two rollsof plastic tape-I (a) Cover the U -bolts bandage fashion first ; Kindly note that we are quite unable to believe it actually came from P. B. Cow and (b) Then proceed to cover the spring, work-carry outthis work, as we have already Co.,ofBerkeleySquare,London,anding from the centre outwards ; informed many people.-GFtEENGATE AND proceeded as follows : (c) Slight tension should be applied whenIRWELL RUBBER CO., LTD. (Manchester).

the secondary shaft, which, in turn, drives A VERTICAL ENLARGER an upright shaft through sixfloors, each (Continued from page 203) Club Note floor being bevel -gear driven from the main Whitefield and District Model and talcum powder or french chalk to remove shaft. any stickiness. Engineering Society The engine is now on its last lease of life It is imperative that the sheet of glass and LAST month theclubhadtwowell assome time this year the entire mill is beingplywood lie flat together. The film nega- attended meetings.On February 7thmotorised, and itwill then be classed astives go between the glass and wood and any a mock auction was held, and on Februaryredundant. curls or kinks in the film must be pressed zist a talk on " Model Diesel Engines" was flat.If you cannot obtain a flat piece of given by Mr. Johnson. plywood, use anotherI -plate orpiece of On March 7th Mr. Priestley will give a plain glass (about isoz. stuff) 4,' -in. by 3÷in. talk on " Constructing a Jig Saw."-Hon. Sec., NEW BOOK The underside of the sheet of glassis A. F. Stevenson,2, NewlandsDrive, covered with a thin card in which the film Prestwich. " Ships and Men."By W. J. Bassett-frame aperture is carefully cut with a pen- Lowke, and George Holland. Publishedknife.When this card has been adhered to by George G. Harrap and Co., Ltd.the glass, it is painted black with ink. OUR COVER SUBJECT 316 pages. Price 15/- net. THE beam engine, shown on the front HERE is a book which has a strong appealThe Electric Lamp cover this month, was built in1861 toalllovers of ships and the sea. The best kind of lamp to use is a 6o -watt and is still providing power for the FieldingWritten in a most entertaining style, the bookopal type, or one of higher wattage. Frosted Johnson Worsted Spinning Mills at Leicester.is a unique and exciting record of the menlamps could be tried, but these give a ball It is believed to be the only one of its kindthat " go down to the sea in ships " from theof light that is not altogether evenly distri- still functioning, and is known as Juno anddays of the coracle to the present era of oceanbuted in places on the bulb end. Plain lamps Jupiter. It has twin beams with cranksgiants, such as the Queen Mary and Queencould be used in conjunction with a piece placed at the unusual angle of 90 deg. toElizabeth. of 3ffi. square opal sheet glass, this resting one another, has cylinders36in. diameter Advances inshipdesign aretraced inwithin the lamp house, at the bottom. How- and was originally fed with steam at a pressuredetail, together with the social and economicever, the opal glass tends to dull the light, of 3o1b. to the square inch, but with modi-reactions brought about by the increases inunless the lamp is fairly close to it, which fications,etc.,it now developed goo h.p.range, speed and capacity. means that the ooal screen becomes rather The flywheel is cast in sections, keyed to a The many excellent illustrationsin thehot and, being close to the film, the heat boss on the shaft by its arms, which alsotext give effective point to the surveys ofemitted may cause the film to crinkle. serves to hold the gear wheel which drivesprogress in maritime construction. (To be concluded.) 212 NEWNES PRACTICAL MECHANICS March, 1947 mixture of approximately equal parts of acetone and The barrel must be cleaned, degreased and very amyl (or butyl) acetate.The solution should processhighly polished. Itislaid in the heated charcoal until a varnish -like liquid has been obtained.Thenuntil the required colour has developed.It is then grind pigment into this until you have obtained the removed immediately, allowed to cool and is well oiled. colour and shade required. Another way isto grind flowers of sulphur into QUERIES For black paint use drop -black or lampblack pigment, turpentine (genuine) so as to produce a thin " milk." plusalittle ultramarine blue.For maroon shadesThis is then rubbed on to the clean barrel, which use " rose pink."For dark blue, use indigo. All latter is then held in a luminous gas flame until dry. these pigments (and many others) are usually obtainable Tice process is repeated until an even colouration has at large paint and materials stores. been obtained. Then the barrel is rubbed well with oil. ENQUIRIES This process gives .a black rather than a blue -black Sparking Plug Tester colouration. T AM building a sparking plug tester, automobile An effective " wet " method of bluing gun barrels -1- type, to take six sparking plugs in a row at is as follows :Mercuric chloride, 4 parts (by weight) ; one time.I have completed the compressionpotassium chlorate, 3parts ;alcohol (surgical spirit), A stampedaddressed envelope,threepenny chamber, which it is proposed to take up to i5olb.8 parts ;water,8.5parts. This solution must be stamps, and the query coupon from the current per sq. in., but am not quite sure of myself inmade up in a non-metallic vessel.Mercuric chloride issue, which appears on back of cover, must be respect of the ignition side. (corrosive sublimate) is a Schedule I poison and may enclosed with every letter containing a query. Could you supply me with a wiring diagram,only be obtained from your pharmacist if you are Every query and drawing whichissent must known to him. bearthename andaddressofthereader. and a list of the various parts needed ? Send your queries to theEditor, PRACTICAL I would like a push-button to set the flow of The solution is raised to just under the boiling point. MECHANICS, Geo. Newnes, Ltd., Tower House, current to each particular sparking plug, and alsoBy means of a clean cloth tied to the end of a wooden Southampton Street, Strand, London, W.C.2. some arrangement whereby a seventh push-buttonstick, it is swabbed liberally over the gun barrel until would set the whole six sparking plugs sparking.the required blue -black shade is obtained.The gun Also, I would like to run the tester off a i2 -voltbarrel is then wellrinsedand dried.Whilst still hot, battery, and at a later date be able to incorporatelinseed oil (raw) is rubbed into it. a transformer in order to run the tester off the The final blue -black colouration depends in shade Cementing Glass Panels in an Aquarium mains.-H.J.Sweet (Aylesbury). on the exact type of steel used for the making of the T HAVE an aquarium, and have broken one ofTHERE are certain difficulties in carryingout the barrel. A the glass panels.Can you please inform me push-button control scheme.In the first place The brown effect which you desire is obtained on of a suitable fixative to use when replacing the the push -buttons would have to deal with switchinggun barrels by means of the following solution :Ferric panel ? The framework is of sheet iron, with five on the high voltage side, or else separate high voltagechloride, 2 parts (by weight) ;mercuric nitrate, z parts ; glass panels forming the bottom and four sides.-generators would be required for each plug.Also ifhydrochloric acid,8 parts ;alcohol (surgical spirit), G. Smith (Birmingham). 8 parts ;water, 8 parts.This solutioa must be made THE following formula provides a good medium for up and used in a non-metallic vessel. A cementing glass panels in an aquarium : It is used hot and is swabbed over the gun barrel Litharge to parts (by weight) ignition by means of a cloth tied to the end of a wooden stick Plaster of Paris ..to parts (by weight) or pole.The gun barrel is then hung up to dry for Powdered resin .. r part (by weight) abouttohours.Afterwards the process is repeated. Dry, white sand ..to parts (by weight) The gun barrel is then rinsed with water, allowed to Boiled linseed oil.. ..Quantity sufficient dry and rubbed lightly with steel wool.Finally it is Mix all the dry ingredients together.Powder very rubbed down with asoftcloth charged with raw finely.Then make into a stiff putty with the linseed linseed oil. oil when and as required. Do not fill the aquarium for three days after cementing. This cement hardens under water.It will stick to Removing Stains on Water Colours wood, stone, brick, metal and glass.It will resist the action of sea water, so that it is useful in the making of T HAVE in my possession two original watt' marine aquaria. colours and, due to age, they have brown A small amount of a cobalt " drier " liquid can be stains on them, possibly due to damp.I shall added to the linseed oil, if required, in order to speed up be glad if you can tell me whether there is any the hardening rate of the putty, but this addition is by Switch methodofremovingthesestainswithout no means essential and, inreality, the slow -drying damaging the water colours.-H. W. Ongley boiled linseed oil gives a rather better seal without the (Mahon). addition of a drier. OU do not say whether the brown " foxing " spots on your watercoloursare in prominent positions 111 III Removing " Fur " from Boilers Battery or otherwise they are numerous. WOULD you please let me have particulars However, with care and patience they can be removed. for cleaning the inside of hot-water Lboilers ? Circuit diagram for a sparking plug tester.- The method is to select a few of the spots (never (H. J. Sweet) more than three orfour ata time) and to paint them -E. Smith (London, W.). over withstronghydrogenperoxide. Apply the THERE are several materials which can be dissolved peroxide with the tip of a camel -hair brush, taking l in small amount in the water of a heating circuitthe six plugs are to be tested in parallel the currentgreat care that the peroxide does not flow on to the in order to remove gradually the inner deposit and capacity of the ignition apparatuswill have to besurrounding area.If possible, apply the peroxide in " fur " caused by the use of hard water.Perhaps the considerable, or some sort of a rotary distributor used to strong sunlight, since the action of the sunlight is to best of these is sodium metaphosphate which, under the connect to each plug in turn. heighten the effectof the bleaching agent.Allow name of " Calgon," is sold by Messrs. Kieth, Piercy, We think the best plan would be to concentrate on a the peroxide to dry off and, if the spots are still present, Ltd., Oldbury, Birmingham.If you will write to this single plug tester ;this could be made to accommodate apply the treatment a second time.If the spots have firm they will, no doubt, let you have a copy of theirthe six plugs i f required, and the test current transferred not entirely vanished after two or three applications of literature on " Calgon " which, we think, will interest fromoneplug to the other by means of a flexible lead the peroxide, paint the remains of the spots with a you very greatly. and connectingclip.The highvoltagecould bewarm solution of oxalic acid (Schedule I poison) of Alternatively,you might writetoSofnol,Ltd., supplied from a hand driven magneto or from an ignition strength, say,apart of the oxalic acid in 3 parts of Greenwich, S.E., for their literature concerning " fur " coil fed from a battery.A make and break should bewater.The brown colour of the spots is due toiron, removalfrom boilers and heating circuits. connected in the primary circuit of the ignition coil.and theoxalic acidsolution will discharge the colour. The best treatment which you can apply consists in This could consist of a telephone type buzzer havingAfterwards the treated areas should be carefully wetted adding a small amount of sodium metaphosphate to thean additional fixed contact connected as shown in thewith warm water and dried by means of white blotting water supply at regular weekly intervals.As a result, accompanying diagram. paper in order to remove as much as possible of the the boiler deposit will gradually be removed. oxalic acid from the paper.Do this several times. Treating Gun Barrels If the spots defy this treatment, they can be bleached Non -acetone Plastic Wood away by amere touch of asolutionof sodium T AM a practical gunsmith and, although I have hypochlorite (the proprietaryliquid" Milton " will WOULD you please supply the formula for a ( I ) a process by which I black gun barrels,I amsuffice), but after this treatment the bleachedareas plastic wood of a non -acetone type, which wonderingifyoucan give me anyurthermust be most thoroughly" spot -washed "inthe will not take too long to harden ? information, as my method is not too per cent.above -described manner in (2) Also, please acquaint me with the constituents efficient. orderto remove every of cellulose paint, and the means of obtaining the Also, what is the method used to obtain the traceofthehypochloritesolution,whichwould colours maroon, dark blue and black.I requirebrown effect on " Damascus " barrels ?-J. H.otherwise slowly rot the paper. this to touch up my car, and so will have to matchWalker (Guildford). Treatment of the spots will leave white marks on the existing paintwork.-G. K. Hinsdale (Liver- the paper indicating where the spots have been.These pool). AGOOD way to blue -black gun barrels is by means must be very carefully touched in with a fine camel -hair ofheatedcharcoal. Thisnecessitatesthebrush charged with water colour.Carefully done, this T1 A non -acetone type of plastic wood can be madeemployment of long shallow trays in which the barrels touching -up will be indistinguishable from the rest of 5, up according to the following formula : can be placed. the picture. Casein .. ..5o parts (by weight) Slaked lime...... 8 parts (by weight) Trisodium phosphate .. 3 parts (by weight) Sodium fluoride .. .. 3 parts (by weight) iiiiiiiiiiitimatiminnintiiiiiiimintiminmininlimiiiiiinummiiiiimiiiiiiiiiinitintlimiliiiinfinininimiiminiiiiiino Naphtha 2 parts (by weight) Fine sawdust = THE P.M. LIST OF BLUEPRINTS 34 parts (by weight) ..- Mix with water to a consistency suitable for tubes. EThe "PRACTICAL MECHANICS " £20CAR SUPER -DURATION BIPLANE' = Another type of non -acetone plastic wood is made up (Designed by F.I. CAMM), Full-size blueprint,Is. on the following lines : 10s. 6d. per set of four sheets. Base 30 parts (by weight) The I-c.c. TWO-STROKE PETROL ENGINE' Wood flour or fine sawdust45 parts (by weight) "PRACTICAL MECHANICS" MASTER Complete set, Ss. China clay .. 15 parts (by weight) BATTERY CLOCK" STREAMLINED WAKEFIELD The " base " above -mentioned has the composition : Blueprints (2 sheets), 2s. MONOPLANE -2s. Manila gum r75 parts (by weight) The "PRACTICAL MECHANICS" OUT- LIGHTWEIGHT MODEL MONOPLANE Methyl alcohol .. 300 parts (by weight) BOARD SPEEDBOAT Full-size blueprint, 2s. Benzol ..3o parts (by weight) 7s.6d. per set of threesheen. (2) All the commercial cellulose paints are of more or P.M. TRAILER CARAVAN' less secret composition.Hence it will be necessary for A MODEL AUTOGIRO" Complete set,10s. 6d. you to experiment until you get the right admixture of Full-size blueprint, Is. P.M. BATTERY SLAVE CLOCK' Is. ingredients.These paints can be made by grinding Theabove blueprintsare obtainable, post free from Messrs. George Newnes, Ltd., TowerHouse, suitable pigments into variouscellulose solutions- Southampton Street,Street, Strand, W.C.2. that is to say, solutions of nitrocotton, cellulose acetate = = or even celluloid itself. An denotes that coPiiruciionaldetails are available, free, with the blueprint. For instance, you can dissolve scrap celluloid in a March, 1947 NEWNES PRACTICAL MECHANICS 213

the lamp being connected to the motor terminals, whilst Soak the glue in the water overnight, during which Fixative for Pastel Drawings the frame of the motor is connected to the other poleperiod it will swell up. Then add the gelatine and heat CAN you give me a formula for preparing aof the supply.If the lamp lights the insulation hasthe liquid gently until the glue has dissolved. Add the fixativesprayforcharcoalandpastel failed.You may also be able to test with the meggerChina clay.Stir well and squeeze through fine -mesh drawings ?It is I think Juniper gum and spirit.between the starting and the running windings if these cloth into shallow trays in which the mass will set and What is " commercial spirit " ?-J. M. Douglas can be separated.If the frame of the motor is notthen be ready for duplicating. (Peterhead). connected to earth it may run even with a definite The mixture of China clay or whiting is not abso- earth fault, although we do not advise such use. When lutely essential but it is advisable, since it gives capacity A GOOD fixative solution based ongelatine maytesting do not turn the megger at full speed if a lowand additional firmness to the hectograph composition. " be easily made according to the following formula: reading is obtained or you may break down the insulation. Ordinary inks do not work well with hectographs.

Gelatine 4 parts (by weight) Alum .. part (by weight) The shock experienced may be due to charge held A suitable ink for this use can be made as follows : Soap .. f part (by weight) by the condenser after switching off.The condenser Methyl violet.. .. 2 parts (by weight) Dissolve the gelatine and the soap in warm water. may be discharged by connecting a small mains voltage Methylated spirit .. 2 " Then add the alum, and stir well.Filter the liquidlamp across the condenser terminals for a few minutes. Sugar r 33 hot through filter or blotting paper. You may be able to obtain resistance wire from Glycerine If the solution has to be kept for any length of time,Messrs. Henry Wiggin and Co., Ltd., of Grosvenor Water .. .. 20" stir into it a few drops of carbolic acid to prevent itHouse, Park Lane, London, W.r.As an example a Any otherdyecanbesubstituted formethyl from developing mould growths. straight length of 3o s.w.g. Ferry resistance wire in violet. The above solution will set to a jelly when cold. open air will attain moo deg. C. with 1.4 amps, 200 (2) If ordinary cement were mixed with 2 per cent. It must, therefore, be used warm. deg. C. with 2 amps, and 300 deg. C with 2.3 amps. of its weight of powdered asbestos, it would probably Another solution for fixative work can be made by 32 's.w.g. Ferry wire will reach too deg. with 1.2 amps,serve your small-scale purpose. So, also, would ordinary dissolving scrap clear celluloid in a mixture of about200 deg. with /.64 amps, and ado deg. with 1.94 amps. cement slaked with waterglass solution. The following equal amounts of acetone and amyl acetate. ThisHigher temperatures will be reached if the wires are formula also makes a good heat -resisting cement. solution is inflammable.It must not be too thick, coiled or enclosed so that free ventilation is impossible. Powdered pumice ..9 parts otherwise it will congeal in the spray. Other types of wire give different results. Powdered asbestos ..z, A solution of gum juniperor,betterstill, gum Mix to requiredconsistencywith waterglass solution dammar, in rectified spirit, is also effective. Transformer Windings (i.e.,rpart ordinary waterglass and r part water). "Commercial spirit " is the name sometimes given to These cements would also fix the tiles on the range. certain grades of industrial alcohol.It is not obtainable T WISH toconstruct a transformer tothe Powdered asbestos can be obtained from Turner by the ordinary public.Industrial alcohol is alcohol A following requirements :Output, 120 voltsBrothers, Asbestos Co., Ltd., Rochdale, or, no doubt, which has been treated so as to render it unsuitable for with tappings at x to v., too v., 90 v., o.ozo amperes ; from a local builder's merchant or paint stores, such drinking.It is supplied duty-free to certain licensed input, 12 volts ;frequency, 5o ;efficiency, 80 peras Messrs. Whittaker and Clegg, Ltd., Hammerton cent.Calculating the weight of core, I find that Street, Burnley. industrial concerns. it has to be 0.25 lb. (4 oz.).By calculation I find that the primary current is 0.25 amperes. The Small Single-phase Motors wire to carry this currentis26 s.w.g.The Making Cork Slabs T WOULD be glad if you would explain the CAN you please inform me what bond is used 1. running (including starting) of the different in making up slab cork, !lin. to tin. thick, kinds of single-phase small A.C. motors. Also 3 to 4ft. square ? fault-finding with an ordinary megger. The slabs are of loose construction and are used I have a one-horse motor with condenser start- 5" for heat insulation, not for carrying loads as ing and I cannot understand how to trace faults when used for noise insulation of machinery.- because I always get a zero reading even though B. H. Eartham (Preston). the motor is running all right. USUALLY no bonding agent at all is used for making Could you also inform me where I could buy cork slabs.The material is hydraulicallycom- resistance wire, about 3o or 32 gauge ? How much pressed in steel dies to a pressure of about ztons per current will resistance wire of this gauge safely square inch pass ?-C. W. Haig (Warrington). Sometimes a thick boiled linseed oil (to the extent of AA FULL explanation ofthe running and starting of about 4 per cent.) is mixed with the cork for bonding all types of single-phase smallmotorswould purposes. At other times China clay is used, and some- involve a very lengthy reply.The commutator types times even a glue solution.Hydraulic compression is of motor are the series, repulsion, and repulsion starting - always necessary. induction motors.Line current passed through the If a suitable press is not available, we would suggest armature of the series motor reacts on the magnetic 4"--1--A that a mix of cork grain and glue solution is trowled field created by the line current in the field windings to into well -greased metal frames and allowed to set. create a torque ;a small motor may be started up by 2. Afterhardening, the glue constituent can be insolu- switching direct on to the mains, but a larger motor bilised by spraying or painting both sides of the pork requires a graduated resistance in series to limit the Dimensions of transformer stampings.- slab with commercial formalin solution.This solution starting current. The speed varies considerably with the (E. Rawnsley.) renders the glue insoluble immediately, besides harden- load. The operation of the repulsion motor is similar to ing it and toughening it considerably. that of the series motor, but in this motor the brushes This latter process would seem to constitute your are short circuited together and are not insulated. The mresaitsetlaync4e).of the primary is 3.85 ohms (approxi- way out of the difficulty in the event of your not being armature is not connected to the supply but acts as the able to get a suitable hydraulic press.The exact secondary winding of a transformer of which the field I have been informed that the windings shouldproportion of glue depends on the particle size of the is the primary and receives its current by induction.obey Ohm's law. Now if I apply Ohm's law with cork used. A few experiments in this direction, how- The speed varies considerably with the load.Thethe above conditionsIfind that the primary ever, will soon put you right. repulsion start induction motor is similar to the repul- E 12 You might be able to hire a hydraulic press from sion machine but has a centrifugal device which shortcurrentis 3 amperes -I-= = -4 =3.Messrs. T. Ward's, of Preston Docks. circuits the commutator when the motor reaches a certainConsequently, with wirethatonly takes.25 critical speed during starting, and also frequently liftsamperes itwill burn out.A similar problem the brushes from the commutator. The short circuited presents itself in the case of the secondary. White Glue rotor is then similar to the squirrel cage of an induction I would be very grateful if you could enlightenCOULD you please give me some information motor and the motor runs at a fairly constant speed onme on the subject.-E. Rawnsley (Leeds). astothe ingredientsformaking white varying load. glue, as used in violin making ?By the look of There are many types ofsingle-phaseinduction ASSUMING the core is tobe built up to hirt.thick, some I have seenI imagineit may contain motor.These differ mainly in the methods employed you could wind the primary with 360 turns ofisinglass.-J. G. Monteith (Ilford). for giving a directional torque to the rotor. Most smallz8 s.w.g. enamelled wire (1,500 amps. per sq. in. of motors are of the squirrel cage type with short circuited conductor) and the secondary with 3,840 turns ofTHE following is a formula for a white glue : rotor conductors which receive their current by induc-44 s.w.g. enamelled wire, having tappings at 3,52o, The rotor3,20o and 2,880 turns.A layer of thin paper should Good quality hide glue ..so parts (by weight) tion from the mains fed stator windings. be wound on after each two layers of wire. Zinc Oxide.. 5 parts (by weight) current reacts on the stator magnetic flux to create The current passing through each winding is only Water .. ..to parts (by weight) the torque, and the motor runs at a fairly constant speedpartly controlled by the resistance of the winding; Allow the glue to stand overnight in contact with on varying load. The shaded pole motor, used in smallthe reactance also has an influence.The reactancethe water.Then gradually bring it into solution by sizes only, has one section of each pole face encircledvoltage is proportional to the strength of the magneticheating the water. Finally,stir in the zinc oxide. by a copper band which acts as a secondary windingfield linked with the winding considered, to the numberThis type of glue sets dead hard and is very strong. and causes the cycle of magnetic flux in the encircled of turns of wire which are linked with the magnetic Alternatively, you might use a casein glue.This portion of the pole face to lag behind that in the other field, and to the rate at which the magnetic field changes.is difficult to make up, but it may be obtained fairly portion so the rotor moves in a direction from the cheaply through any good paint stores, such as Messrs. plain to the encircled portion. The reactance is the principal factor in controlling the The stator windings of the split phase inductionprimary magnetising current, the reactance volt dropJames Beard and Co.,Ltd., Great Ancoats Street, motor have a running winding and an auxiliary orbeing almostequaltothesupplyvoltage. The Manchester. starting winding. The auxiliary or starting winding may secondarycurrentwillbelimitedpartlyby the be designed to carry current continuously or may bereactance volt drop of the secondary and partly by the Gyring Rabbit Skins intended to carry current only during starting.In theresistance of thewholesecondary circuit, not merely former case the motor can be started by switching the resistance of the secondary winding.It followsWOULD you please tell me how to cure rabbit direct on to the mains. Many motors are of the latterthat the secondary may overheat if itisoverloaded, skins so that they remain soft and pliable, type, however, and the starting winding may burn outi.e., if the resistance of the secondary load circuit is as I wish to make gloves from them ? Isit if left in circuit.To avoid this the starting windingtoo low.In order to minimise the secondary reactancenecessary for them to be dried by sunlight, or may be switched out by a centrifugal device in the motorvolt drop the primary and secondary windings should will any heat dry them ?-D. W. M. Latimer which acts at a certain speed or may have to be switched be wound as closely together as possible in order to(Liverpool). out by hand. The magnetic flux created by the startingminimise leakage magnetism. IN order to cure rabbit skins, stirpart (by measure) must be displaced both in space and time from that of bran into 3 parts of boiling water.In every created by the running winding to create a directional Hectograph Composition gallon of liquor so prepared dissolver lb. of common torque.The former is obtained by fitting the starting alum and Ilb. common salt.Clean the skins as coils midway between the running coils, whilst thefrCOULD you give me details of a simple thoroughly as possible, removing flesh and fat.Then latter is obtained by connecting a resistance, choke coil, duplicator :(a)isit made of wax or asoak them in the above liquor at ordinary temperature or condenser in circuit with the starting winding. Ingelatine solution ?(b) Can it be used with ordinary for 24 hours.Allow the skins to dry (in the shade). some capacitor motors a condenser is connected inwriting paper and ink ? Then stretch them and rub them well together. Repeat circuit with both windings. (2)I am also interested in making a modelthe process twice more, repeating the stretching and It should be realised that only a limited degree offire range fitted with electric elements for heating.rubbing.This latter procedure is most important. testing is possible by means of a megger. The principal Would ordinary cement be too brittle or heavy ?The more rubbing the skins get, the softer and more test is an insulation test with the megger connectedHow could I fix the tiles on the range ?-F. Fosterpliable do they become.If the rubbing has been between the windings and motor case.In our opinion (Nelson). efficient, the skins, after the third immersion in the a minimum satisfactory result for this test is o.1 megohm, THE following formula makes a good hecto- bran liquor, should be as soft as chamois leather.It although motors have run for years with a much lower ( I )graph mess for duplicating work : is a good plan finally to rub a very little neatsfoot oil Glue .. zoo parts (by weight) into the skin in order to assist and preserve its pliability. figure.The zero test mentioned may indicate merely The skins should not be dried by sunlight; rfor weak insulation or an actual failure.The latter may Glycerine 500,, be verified by connecting one pole of the supply (the China clay or whiting 25 should heat be applied for drying them.Slow drying live pole) to a mains voltage lamp, the other end of Water .. .. 375 in a cool place is the best. 214 NEWNES PRACTICAL MECHANICS March, 1947 -ELECTRADIX- Modelcraft's BARGAINS HEADPHONES. Single low resistance OPPORTUNITIES MODEL phone for circuit test- ing or house telephone, 60 ohms, bakelite case YACHT andcap,bestBritish IN PLASTICS make, with headband PLANS and cord,816. Amost informative High resistance handbookentitled" OPPORTU NITIES double headphones, as IN PLASTICS'' is now availablefor distribution.Thisguide new,with headband discusses in considerable detail the prospect of careers in all branches Get ready and cord, type S.G.B. of the PlasticsIndustry -knowledge required,salaries,possibilities light weight, sensitive tocrystal,22 6,de- of promotion, and so on -and explains how you may prepare for these for spring livery from stock. opportunities through our modern home -study courses. TELEPHONES for House and Office. CONSTRUCTORS PARTSFOR YOUR We specialise inPlastics training and our courses are authoritative, OWN SET UP ! up to date and comprehensive.The range of our tuitionis wide, WALL TELEPHONE SETS. covering Elementary Instruction in Basic Subjects, PLASTICS Bracket Mike, vertical or horizontal 10/ - Transformer and Condenser for TECHNOLOGY, coachingforthe CITY AND GUILDS same 51 - EXAMINATIONS, andspecialisedinstructioninsuchspecific Magneto Bell fitted 51 - branches of the industry as :- GULL A fine,racing model, Switch hook and contacts 216 !Bins. long, which is going Walnut Cabinet 8in.x6in.xSin Plastics Mould Design, Plastics in the Paint, Varnish to take a lot of beating 3/41tPost fitted terminals and connections 516 this summer. , 2d. Two L.R. watch pattern earphones 101 - and Lacquer Industries, Plastics Costing and Estimating, Hand Magneto Ringer 101 - Plasticsfor the AircraftIndustry,Plastics for the PIXIEA toy with a lineal. Post SET As above 301- or 501- for 2 sets performance.fairll 2d. INDUCTOR ALTERNATORS. Output Electrical Industry, Plastics for the Building Industry, 4001500 watts single or 3 -phase 50 cycles, PlasticsinSalesPromotion,PlasticsinTextiles, separate 12 volt excitation needed, 4 poles, Designing inPlastics, Synthetic Rubber Technology, speed 2,800 r.p.m., totally enclosed.Ball etc. bearings ; made to Government specifica- Just Out tion ; as new and guaranteed, £8 10s. each. Ali courses are conducted under a guarantee of MOTORS. D.C. Fan motors110 and Model craft'sFebruary 220 volts D.C. large bulk -headsize,351-. IlH.P. 220 volt D.C. Newton motor, " SATISFACTION OR REFUND OF FEE " MAGAZINE &LIST 2,500 r.p.m. shunt wound ;ball bearings ; a' forModelroakers £12. Small Universal motors 1125th H.P. OPPORTUNITIES IN PLASTICS " will be sent on request, By Modelmakers 230 volts A.C.ID.C. 4,000 r.p.m.,70/-. free and without obligation.The book contains so much useful 48 pages of articles, SMALL MOT ORS for model experiments Colour card cover. information and guidance that whatever your interestin hints, news.Nearly 350 items III 3-8 volts D.C. or from A.C. mains through Plastics orfrom Yourlib listed. Direct 6d. a transformer, 151-; transformer, 716 extra. may be, you should make a point of writing for your copy at once. List Only D.C. FANS. 1101220volts,oscillating mode:shoe. tabletype byleadingmakers ; I2in. blade and guard, 551- each. HAND MAGNETO GENERATORS, 'BRITISH INSTITUTE OF PLASTICS TECHNOLOGY Modelleruft Ltd output approx. 70 volts 25 ma. A.C. perm. steel magnet wound armature driven by 4, SHAKESPEARE HOUSE, gearing in handle, 101- ea.3 magnet type 77(L) Grosvenor Road 1216,postageII-extra. MILLIAMMETERS. D.C. moving coil 17, STRATFORD PLACE, LONDON, W.1 LONDON S.W.I milliammeters 0-15, flush panel type 21 in.,25/.., 0-I ma., 551-, 0-500 microamps, 65 -. SWITCHES. Dewar keypaneltype WORM DRIVE 8 -poleC.O.flushfitting,Si-. Yaxley CHEMISTRY APPARATUS JUBILEEHOSE CLIPS 3 -pole3 -way, 316 ; 8 -poleI -way, 316. Send Stamp for D.P.C.O.Toggleswitch250v. I amp., The long -life MIDLAND INSTRUMENT Co. flush panel, 313.8 -way Lucas switch box, COMPLETE PRICE LIST INSTRUMENT WIRES and resistance 316 ; 6 -way, 3/, clip with the wires, send for latest stock list. MICROPHONE BUTTONS, are sound Booklets : ever -tight SPECIAL OFFER OF EX-GOV. transmitter units, every button guaranteed grip ALL DRY BATTERIES. brand new, a marvelof acoustic " Experi- air -tight,tropical standard,highest ments " 7d. grade manufacture, fully guaranteed : engineering design, as TheBest Known 90-v. H.T. plus 1I -v. L.T.. 5/-, Post 841. used bytheG.P.O. "Formulas"so For In sealed cartons of 8, 35'- post paid. For amplification and Radiator Joints, Above can easily be split to form three detection of sound for Air, Oil and 30-v. H.T. units (size of U.2 cell) ideal for all purposes.Lin.dia. " Home midget sets, deaf -aids, etc. WaterHose EX-GOV. D.C. MOTORS, brand new brass body forms the Chemistry " Joints granule chamber, 213 boxed. 1224-v. 1 -amp. twin -ended We guarantee a 5!321n. shaft, superior precision ball - diaphragm of thin mica, Post Paid Tight Joint bearing lob, size 31n. long, 2in. sq., 20/-, needs only a small post 8d. pocket battery, 316 BECK(Scientific Dept. A) 230150-v. A.C./D.C. MOTORS, speed L. ROBINSON & Co. approx. 3,000-r.p.m., weight albs.. each. High Ratio G.P.O. Mike Transformer, Fitted gearbox (detachable) with three 416 each. Prices include instruction leaflet. 60 HIGH STREET, 25, London Chambers, powerful reduction drive shafts, speeds CRYSTAL SET. The Stoke Newington London N.16 approx.4,8 and 16 r.p.m.Superior --- GILLINGHAM, KENT make,ball -bearing.401-, post paid. Lesdix Bijou Crystal set V -pulleystofitinitialdriveshaft, inbakelite case,semi - 1/3 extra. perm. detector, con- ADANA PRINTING MACHINES RECTIFIER AND TRANSFORMER denser tuning. 151-. DURALCMIN AND Print in the odd hours with an to charge one 2-v. accumulator at ALUMINIUM SHEETS 4 -amp. from 200:250-v. A.C. mains, 13/6. Headphones 2216 pair, Duralumln, Adana -still the most absorbing with cords. of crafts.No.111.9 Post 8d. 413in. x 24in. x22 S.W.G. 13s. each Machine 14.10.0. No.2 RELAYS, 40 -ohm. A.C. d.p.c.o., 2/6. G.P.O. TESTING GALVOS. Vertical 36in. x 24in. x 24 S.W.G. 8s. ed. each, H S Machine 19.15.0. Twin polarised 25 -ohm. relays, d.p.c.o.. post free. Willpay foritself 7/6.Powerful 6-12-v. solenoids, fitted circuittype, 151-. Moving Coil Tinsley Soft Aluminium, 20 S.W.G. in sizes up in a month or two plungers. 2/6. mirror galvo100 ohms resistancewith to aft. x 411. 2s. per sq. ft., plus carriage. Send stampforillus MICROPHONES, hand type, bakelite mirrormovingcoil,in polished case, Inquiries invited for various sections. tratedfolder to Dept. case, carbon, 5/-, trans. to match, 2'6. £510s. COMPETITION CARS, P.M.4,Adana (Printing Headphones. twin type,fitted cords, CABINETS. The celebratedMarkIII Vine Grove, Blossom Way, Ltd.,15/18, ChurchSt., H.R.. 91-. Ditto, balanced armature Hillingdon, Middx. Twickenham.M1,1Ix. reed type. L.R.. 12/6. canvas covered Ain. mahoganycabinet RECTIFIERS 30.16, 94.Signal lamps I3in. x I2in. x 7.1in., hinged lid and carrying (red), 1/-.2 -mid. conds., 1/- ; 4-mfd., handle, IV-. SHE WORLD'S GREATEST BOOKSHur 1/6.Mains a.c. magnets, 2!.. Counters MAGNETS. D.C. Electricmagnets, 0-999, 1.'8.Shocking coils, 2-4-v., 7/8. Useful and attractive steel boxes. size weight 10oz., lift on 2 volts, !Vb., 4 volts 8iin. x 5fin. x 51n. with lid. 5'-. 31b., 6volts 41b., new surplus, 716 each. elm 0 R. ,,,BOOKS AMMETERS, moving coil with Permanentpowerfulflat bar magnets, For increased power, Im- thermo-couple,.5 -amp. byWeston, 2in. xlin.xin.,drilled 2 holes each proved petrol consumption. New and secondhand Books on every sub;eit Ferantti, etc.. 10/-. Moving coil 30-m.a. end, for any pole pieces, 21- pair. A.C.ID.C, better starting.Send for - BOOKS BOUGHT -- meters. 15/-. mains magnets,2 -pole.220volts, 716. interesting booklet Z17. P.V.C. twin -flat flex 14136. in various 119-125, CHARING CROSS ROAD, colours, 4d. yd.100 yd. coils.25:-. The wonder Midget magnets, Alni perm. LONDON, W.C.2. Cable, T.R.S. twin flat, 11044, 9d. yd. steeldisc. ; in.dia., in.thick,with Gerrard 5660 116 lines).Open 9-6 (inc. Sat.) 3;029, 1/- yd. ;7/029, 118 yd. 31I6in. centre hole, 316 each.Large stock SAMPLE BOXES OF RADIO & of Horseshoe magnets.Send for special ELECTRONIC PARTS,over 100. 5'-, Magnet Leaflet" P.M." post 8d.Cartons of surplus radio and RATCHET & REVOLUTION " VIBRO-ARC " Engraving Pen electronicparts,contains rectifiers, PARCELS.71b. useful oddments for the conds. switches, signal lamps, junkbox.All clean,dismantledfrom COUNTERS For rapid engraving any mechanisms, etc.,etc.,weight over Government and other surplus apparatus, metal -hard or soft. 101b., 20,-, Post 1/2. Ask for 71.77.1.s, Also hundreds of other items, send for 716 post free.(Not for Overseas buyers.) 10/- Operates from 4-6v. Leaflet No. 18/4 our new March lists. 2.1.withs.a.e, Please include postage for mail orders. Battery or A.G. Trans - Orders over 30/- post paid. No C.O.D.- Speed up to Post former. under El. 6,000 r.p.m. Free 18 Harborne Park Road, ELECTRADIX RADIOS B. & F. CARTER 444%4Alia, HOLBOROW, 214, Queenstown Road, London, S.W.8 Birmingham, 17 & CO. Ltd., Bolton 5 (49)Borougbbridge, Yorks. Telephone : MACaulay 2159 Tel.: HARborne 1308. MODEL ENGINEERS GALPINS FOR THE TURNER : ELECTRICAL STORES Lathes, 31 and 41 S.S.Bench Millers.Drilling Machines. WHY WORRY? 408 HIGH ST., LEWISHAM, FOR THE WOODWORKER : LONDON, S.E.I 3. Telephone :Lee Green uses an immense 0309.NearLewishamHospital. Wood Turning Lathes, 21" and 51- centres. 4in, Planers. Saw WORRYamount of vital force.People TERMS: CASH WITH ORDER. Benches.Sanders. Spindle Moulders. who worry not only use up their REGRET NO C.O.D. energy during the day by worrying, ELECTRIC LIGHT CHECK METERS, Sets of Castings and Blueprints for Circular -saw Bench and Power but they rob themselvesofthat K.W.H.type,forA.C.only. 2001250 Hacksaw. greatestofallrestoratives,sleep. volts 50 cycle, I phase, 5 amp. load,1216 People who worry can't sleep. They each ; 10 amp, IV- ; 15 amp.,201- ; lose their appetite.They often end 20 amp, 251- ;30 amp,30/-; 50 amp, Every known Small Tool in Stock. Electric Motors available. 401- ; 100 amp, 50/-.Carriage 116 extra up by getting really ill.How often on each, all guaranteed. have you hearditsaid," Iam USEFUL PANELS, consisting of chokes, NUTTALL'S (LATHES) LIMITED, worried to death " ? resistances, mod. transformers, con- MANSFIELD, NOTTS. densers, calibrated to decibels, and various What doyousupposewould other components, all mounted on metal happen if a person who was putting baseplate, size19 x 5 x 5,101- each, post himselfinto and 216 ;19 x 8 x 5, 151- each, post 216;19 x 12 Copper wires. Cotton -covered Ilb. reels, SAN(,iAMO SYNCHRONOUS mental,moral, x 5, 201- each, carriage 316.All compon- 18.20g., 1/6: 22.24g.. 1/9; 25,28g., MOTORS, physical bankruptcy by worrying, ents as new. Makers Standard Telephone. 2/-30. 32g.. 2/3 ; 34g.. 21. Enamelled self-starting, exceptionally good torque; weretoconvertallthisworry do., same prices, including 36g., 2/6; rotor speed 200 r.p.m., 200-250 v. A.C., EX-G.P.O. PRE-UNISELECTORS, 3 38. 40g., 21. Silk -covered 2oz. reels, 50 c. Consumption 21 watts. Size, energy into constructive action ?In ohm automatic relay operating a 4 -way 24, 26g., 1!6 : 28, 30g., L 9 : 32, 34g., 2/- 21 x 2.Geared 1 rev. 60 min., can be no time at all he would have accom- Yaxley switch,fittedwith2 condensers 36.38g., 2/3 :40.42g., 2/6: 44.45g., reset to zero by friction drive from plished so much that he would have .01, 11 M.F., new, boxed, 51- each.G.P.O. loz., 2/- ;18g., 11b., 7/- 22g., ilb., 2/6. front or back.Shaft gin. x 1/10 to run Laminated Bakelite panels, fin, thick, clockwise :ideal movements for mak- nothing to worry about. PolarisedTelegraph Soundersin new gin. x 4in., 1/6 : 6in. x gin., 2/-; gin. x ing electric clocks, time switches, etc. condition, IS!- each. G.P.O. Polarised 61n., ; 10in. x 6in., 3/-; 10in. x gin.. Nickel -plated finish.Price, 221 each. Relays, operating on10120 mlamps. coil 3/9 ;12in. x gin..4/6.Ditto, 1/16in. 12 to 1 Dial Trains to fit above spindle, Nothing is more discouraging to resistance, 230 ohms, 151- each, as new. thick, same sizes, 1/-, 1/4, 1/8, 2/-, 2/6, Per set, 2/6. a worrying person thanto have SHUNT WOUND D.C. 110 volt 3/-. Polished Ebonite panels, 3/161n, As above with CHAMBERLAIN & thick, sizes as above, 21-, 3/-, 319, 5/-, HOOKHAM SYNCHRONOUS someone say,' Oh, don't worry, it motors, 1,500 r.p.m.,approx.r h.p., 8/6,7/6, respectively. B.A. screws. MOTORS (Enclosed Type) 25/-. will all come out right " I condition as new, 1716 each, post 21-. gross useful sizes, 2/6, do., nuts, 2/6 MOVING COIL HEADPHONES, P.M. LARGE SIZE I MFD. CONDENSERS, gr. ; assorted gross screws and nuts, Energised by Alni Magnets, 45 ohms, This is not reassuring at all.The at 4,000 v.wkg.,101- each, carriage 216. 2/6 gr.;brass washers. 1/6 gr. fibre tin. Coil.Ideal for Mikes, Miniature " Selenium Rectifiers," output 200 volts washers.3.16 gr.: assorted soldering Loudspeakers,etc. llin.overall in worrying one can't see how itis tags, 2/- gr. :assorted small eyelets Bakelite cases with 3in, front flange, at I amp.,half -wavetype, 2716each. and rivets, 1/3 gr. New ex-G.P.O. hand going to come out all right.But if Instrument Rectifiers, 5 mla., and 10 mla., telephones with microphone, switch MOVINGCOIL MICROPHONES, the men and women who worry 416 each. Ex-G.P.O. Multi -Contact Relays, and cords, 12/6. Rubber -covered stran- fitted as handinic.with switch in handle, could be shown how to overcome 5/- each. ded copper wire, lid., tad. yd. Tinned 45 ohms Speech Coil. 10/- each. the troubles and difficulties that cause EX-G.P.O.HANDSETS. The latest copper connecting wire,20ft.,8d. ; PRE-SET LAMP HOLDERS, suit- type (black bakelite),1016 each, post do., rubber -covered, 10ft., &I.Finest able up to 500 watts. Sturdy construc- worry, they soon would cease quality stranded and single -push -back tion, 3/- each. wastingtheirverylife -bloodin Singleearphones,lowresistance,with wire, 12 yds., 2/3. Resin -cored solder. MANGIN MIRRORS, 21 inch.Hole headbands, 416 each.Ditto, 2,000 ohms, ilb.. 1/-,New " Lucerne " permanent in centre 4in. dia., 3/6 each. worrying. Instead, they would begin 716each. BellBoxes,standardpattern, crystal detector, 2/- : semi -perm. peri- DIMMERS,220 volt, 2,700 ohm, .27 devoting their energiesto a con- 616 each. Ballast lamps, 125 volts 30 watts kon detector, 2/6." Lucerne " crystal amps.Stud Control.In brass cases, structive effort that would gain them set coil with wiring instructions, 3/6 : or100 ohms resistance,E.S.holder,61 - 7 x 7 x 4, 30/- each. glass tube crystal detectors, complete, CASH WITH ORDER, POST PAID freedom from worry for the rest of per dozen. 2/6. Reconditioned headphones, 4.000 ON ALL ABOVE GOODS their lives. EVERETT EDGCUMBE 23in. METERS, ohms, complete, 12/6. Used ex-R.A.F. TO CALLERS ONLY.A comprehensive 0 to 5 volts ACIDC, incorporating Westing- low resistance earphone with switch. stockof scientificinstruments,meters, Rectifier,4716.Ditto,calibrated bargain, 2/6.All postage extra. Trade You say that sounds plausible, but house supplied. gears, relays. etc. indecibels --3 -10, withrectifier,651-. POST RADIO SUPPLIES, H. FRANKS: Scientific Stores, can it be done ? Another reading 15-0-15 mlamps.,351.. 33, Bourne Gardens, London, E.4. 58 New Oxford Street, London, W.C.1 Ditto, 30-0-30 mlamps., 351-. These meters TEL.: MUSeum 9594 H.M. FORCES are all first grade moving coil instruments. All serving and ex -service members VARIABLE RESISTANCES, worm are now entitled to receive the com- wheeldrive,2,000 ohms,tocarry 250 " OSMOR " plete Pelman Course, with full tuition mlamps, 351- each. Electrolytic Con- and guidance, at densers, 2,500 mf., 25 w. wkg., 251- each ; 250 inf. 250 v. wkg., 151- each. RADIO HEART One -Half Usual Fee. MAINS TRANSFORMER, 2001250v. Comprises :-Chassis. IFs. Pre-set, Immediate application should be made Primary, 500101500 v. at 150 mla., 4 v. 4 a., V. Holders. S.M. Drum, Drive, etc. for Special Enrolment Form (Services). 5v.3a. and 6 v.5 amps., 551.. Ditto, Coil Pack(3 -wave), Choke. Dropper. 350101350 voltsat1001120 mlamps, 4 v. 2 -gang. 8-16 mfd. Dial. Pointer. Knobs. 4 a., 5 v. 2,6 v. 4 amps.,price 3216, post All Cons. and Resistors. It can be done, and is being done, 116. EX - G.P.O. VERTICAL TYPE Fitted ready for wiring up. £6 Its. by Pelmanism every day in the year. GALVANOMETERS, centre zero read- incl.3 drawings. The Hallant This is all the more remarkable be- ing3010/30,716 each,postII-.Mallory Foundation of a Quality Superhet. p r" Arro Petrol httt_-: cause to -day the whole world is in an new and unused,716 12 volt vibrators, 8in. P.M. Matched Speaker 301-. upsetconditionandpeopleare each. Electrolyticcondensers, 80 mf. Attractive Cabinet £3 10s. worrying to an unusual extent. Yet, 350 volt wkg., 516 each, post 9d. EASILY MADE FROM OUR. CASTINGS. WESTON MOVING COIL METERS, Write for Literature. every mail bringsletterstothe edge type with knife edge pointers, J. HALLAM & SON Pelman Institute from grateful scale, all 2 mla. F.S.D.,0 to 300 mla., 301-; MORGAN OSBORNE & Co., Ltd., UPTON, POOLE, DORSET. Pelmanists whohaveceased to 0 to 2 amps.,27(6; 0 to 60 volts, 2716; South View Road, Warlingham, worry. 0 to 150 volts, 27(6; ditto, 0 to Ivolt I mla. MINIATURE PETROL ENGINES for 1,000 ohm per volt,351- ; another 301 Surrey. Aeroplanes and Speed Boats. People to -day are all too prone to model 0 to 3 mla., 351.; 0 to 50 mla., 301-; Send 3d for new list. 0 to 200 mla.,3216; another 501model complain that they just have to 0 to 50 mla., 2716 ;0 to 10 mla., 2716. -RADIO CIRCUITS - worry. Butonce theybecome EX -GOVT. ROTARY CONVERTERS, Pelmanists they cease this negative input 12 to 18 volts D.C. at 3k amps., output AND COMPONENTS form of thought. 450 volts 60 mlamps., fitted with automatic switching and smoothing, 3216 each,216 " DORSET" SERIES Remember -Everything you do is carriage.Also a few only to clear, as above, preceded byyour but without brushes or brush caps, at 201 - NEW BATTERY SUPERHET attitude of mind each, post 216. 4 -VALVE ALL DRY 3 -WAVE ERNEST TURNER, moving coil mlamp. PERFECT PASTIMES FOR A.C.5-VALVE3-WAVESUPERHET The Pelman Course is fully des- PLEASURE AND PROFIT a meters, 2in. scale 0 to10 mla., 0 to 20 A.C./D.C. 5 -VALVE 3 -WAVE cribedin bookentitled"The TheCourse mla., 0 to 50 m!a., 2716 each ; allfully Plastics, Models, Toys, Lampshade SUPERHET Science of Success." 'guaranteed.Standard Telephone 3in. scale frames -patterns -coveringmaterials, A.C.1D.C, AMPLIFIER, 6-8 WATTS is simple and interesting, and takes mlcoil meters, calibrated to read 0 to 25, Leather Punches and Leather Fittings, up very little time ; A.C.1D.C. 4 -VALVE T.R.F. MEDIUM you can enrol 100 volts movement, 1 mla., incorporating Raffia, Erinoid, Plastic Handicraft on the most convenient terms.The metal rectifier, 451- each. Wire, etc. WAVE WITHL.W.CONVERSION book will be sent you, gratis and D.C. MOTORS, approx. h.p., either Send 3d. for pricelists, orI Id.for Manuscripts containing 5 or 6 pages post free, on application to 110 v. or 230 volt, D.C. mains, series wound, specimen copy of of drawings, point to point wiring 201- each, post 1/6. Mostly with laminated instructions, etc., 5/- each, post free. fields. CRAFTWORK MAGAZINE Theoretical circuit of superhets with EVERETT EDGCUMBE 3 READING (which includes price list) parts price list, 2)d. each. PelmanInstitute VOLT -METERS, 0 to 5, 25, and 250 volts, Dept. 2, Homecrafts, The Broad- (Established over 5() years) 4in. scale, complete in teak wooden carrying way, Broadstairs, Kent. WELDONA RADIO ACCESSORIES, :case, 50/. each.One only, Ship's Sextant LTD., SWANAG E 130,NorfolkMansions, , (Makers, H. Hughes), conditionas new, £8110!-. THIS MONTH'S SPECIAL -Plans to make Wigmore Street,London, W.1. BOOKS a 36in. model of the " Vosper Motor Torpedo SMALL ELECTRIC MOTORS for A.C. " Toys from Scrap for Pleasure or Boat."Two sheets giving every detail. Callers welcomed. or D.C., 801100 volts,useful for sewing Profit," 3/6. by W. Lee. Can be driven by petrol or electric. !A PELMAN (OVERSEAS) INSTITUTES: PARIS: machines, Pathe Cine's, etc., double " The Art of ScaleModel Aircraft splendid job. 12/10 post paid. ended shaft, 30/. each. Building." 4 11, by V. J. G. Woodason. Plans to make a 36in. model of a " Cargo - 176,Boulevard Haussmann. AMSTERDAM: " How I Toured the World on Nothing," Passenger Liner." Two sheets giving every Damrak,68. NEW YORK: 271North ,VOLTAGE CHANGER TRANS- 116, by W. Buehler. FORMERS, auto wound, fully guaranteed, Publishing for Pleasure -and Profit " detail for building a beautiful merchant Avenue,NewRochelle. MELBOURNE: vessel. Can be powered by steam or electric, 396 Flinders Lane. JOHANNESBURG : immediate delivery, all tapped 0,110, 200, (How to start and run a publishing 1210 post paid. 220, 240 volts 250 watts, 451- ; 350 watts, business), 3/6. List of kits and plans, two penny stamps. P.O.Bor 4928. DURBAN: NatalBank 551- ; 500 watts, 70/. ;1,000 watts, £511510; " Money in Exports " (Trading ia 41 Chambers(P.O. Box1489). DELHI : 10 different markets), 10/6. Write name and address verydearly. 2,000 watts,£811510. T. FITTON (Model Specialist), Alipore Road. CALCUTTA:102Clive Street. USEFUL PUBLICATIONS, 4,Ann Terrace, Norwich Rd., E. Dercham, 17. Alitavvoh. Landon. W.C.2. Norfolk. 216 NEWNES PRACTICAL MECHANICS March, 1947 "fee Britain ).7

0 SPEY VALLEY.... Some of Britain's most beau- tiful scenery is in the 110 -mile course of the river Spey from Mt.Clach -a - Cheannaiche, Inverness-shire, to the Moray Firth.Through misty Loch Spey and Loch Inch the river flows past the grim, majestic peaks of the Cairn Gorms. At Kingussie, where the River Spey is 100 feet wide, and at Strathspey too, the grandeur of the scene is DUNLOP unforgettable.

611/315

When a turn intheroadbrings yousuddenlyfacetofacewithan emergency and fingersinstinctively grip the brake,itis good to feel the instant and smooth response ensured by FERODO All -Weather Brake Blocks March, 1947 THE CYCLIST 41

All letters should be addressed to theEditor, "THE CYCLIST," georgeNewnes, Ltd., Tower House, Southampton Street, S tr and, London, W.C.2. Phone : Temple Bar 4363 Telegrams : Newnes, Rand, London VOL. XV MARCH, 1947 No. 301

Comments of the Month By F. J. C. Cycle Show Postponed THE announcement that there was to be a" Calling All Sportsmen " revealed as being ' black spots.'The pro- Cycle Show thisyear gaveriseto gramme will include the improvement and pleasurable anticipation among the industry THERE are many who pay lip service toprovision of footways and other measures and cyclists, who felt that this would be one thecleanlinessof cyclingsport anddesignedtopromotepedestrian safety. step towards relegating the war to the limbosportsmen. We therefore appeal to themTraffic signs will also be modernised, and offorgottenthings.Itwas withsometo exercise their sportsmanship and to refrainother measures taken which will contribute astonishment, therefore, that a later announce-from attacking branches of the sport with whichto greater road safety.The human factor ment gave the depressing news thatthethey may disagree.Each of us is entitled tocannot be eliminated from road accidents, Council of the British Cycle and Motor Cycleour view:, and we may not agree with thebut itseffects can be reduced, and every- Manufacturers' and Traders' Union, Limited,other man. We should, however, be particu-thing that can be done to ensure that failure had met and decided that after all there wouldlarly careful not to endeavour to force ourof judgment does not necessarily result in not be a Cycle Show this year. views on others. an accident must be done. These commentsare encouraged by a " We are already carrying out a large pro- They were forced to this decision afterbroadcastunderthetitle" CallingAll gramme of re -surfacing of existing highways consideringthe important changes whichSportsmen," in which a known antagonist ofin order to reduce wartime arrears and to have taken place in the industrial situationmassed start racing gave his views on it. following a further restriction in the supplies rectify the damage caused by military opera- There was no one present in the debatetions.This programme will be continued, of steel and othervital materials by therepresenting the B.L.R.C. and thus the publicand we intend to make the fullest possible Ministry of Supply, and the shortage of otherhad a one-sided view of the problem presented materials necessary to this industry such as use of modern plant in carrying out this to them. work.Special attentionis being given to chromic -acid. We should like to ask the B.B.C. and thosethe provision of non-skid surfaces and, what These difficulties, added to the restrictionsresponsibleforplanningthisparticularis equally important, uniformity of surface on the deliveries of fuel, have placed thebroadcast the following questions : conditions. bicycle industry, one of the leading export (1) Who was responsible for framing the " I am very glad to know that although industries, in a peculiarly difficult position.questions ? your federation may hold different views on In these circumstances, and bearing in (2) Who was responsible for selecting thosethe question of transport nationalisation, you mind that the industry must concentratetaking part in the debate ? are entirely in accord with the Government as far as possible on its production problems, (3) Who selected the subject of massedon the general plan of road developments. the Council decided by a majority that thestart racing ? I believe that this exhibition will demon- time and energy which would be required to (4) What steps did the B.B.C. take to makestrateto the public that the expenditure organise a thoroughly representative Cyclequite sure that the questions submitted werenow contemplated will he a sound invest- Show could only be secured at the expense ofnot inspired questions sent in by members,ment and will be more than offset by the production, and they have decided, therefore,say, of the N.C.U., which is, of course, anti -saving in lives, in time and tempers, and not to proceed further with the arrangementsmassed start ? in wear and tear of vehicles.For this reason which they had in hand for the organisation of (5) Willitgive the B.L.R.C. an equalandinthis hope Iwish the Highways chance of putting its case ? Exhibition every success." a 1947 show.They still hope to organise (6) Why did not the person responsible a show in the autumn of 1948, nine years afterfor the broadcast, and knowing the questionsFrench Study British Games the commencement of the last war ! which were to be put, go to the only source AT the invitation of the Central Council Nine years is a long time in the life of anywhichcouldsatisfactorilyanswerthem, of Physical Recreation and the British individual.The allotted span is three scorenamely, the B.L.R.C. ? Council, a party of French medical special- years and ten.Nearly 16 years of that time (7) Why were only anti -massed startersists has arrived in England to study British have been spent in wars.We are still urgedinvited to take part in the debate? methods of physical recreation with a view to go on saving for the future, when the future (8)Is the B.B.C. aware of the Leagueto their possible adoption in France. has arrived, and is passing. Memorandum to the Ministry on this subject, Led by Dr. C. Churche, who proposed the The Cycle Showisone of ourbestand is the B.B.C. aware of the fact that if thisvisitafterattendingoneoftheCentral ambassadors, but in view of the tragic cir-form of racing were illegal it would have beenCouncil training courses in 1945, the party cumstanceswhichnow surroundBritishstopped a long time ago ? includes 25 doctors and medical students industry we think the decision of the Council (9) Is the B.B.C. aware that massed startwho attended a course this week at Upping - isaright one.Manufacturers arebesetracing takes place on the Continent ? ham College and 6 doctors who attended a by incredible difficulties.They are controlled,Motor Roads similar course at Bisham Abbey, Berks, the badgered, pestered for figures, worried by national recreationcentreofthe Central form filling,shortage of coal, shortage of MR. BARNES, Minister of Transport,Council of Physical Recreation. labour, and shortage of materials.There is recently statedthatitisproposed, Dr. Jean Martin, consulting physician in little point, therefore, in staging an exhibitionsubject to the approval of Parliament, toParis to leading sports organisations, sum- which would merely encourage a commodityputinhandduringthelaterstage of the ten-yearplan a number ofming up his impressions of the course at demand for goods which the industry could Bisham Abbey, said:" The chief difference not supply to the home market. motorroadslinkingsomeofthe main centresofpopulation. The exclusionofI have already noticed is that the method of Indeed, it is doubtful whether during theslow -movingtrafficfromtheseselectedtraining followed by the Central Council of present year they will be able to supply all ofroutes would involve a drastic departure inPhysical Recreation is less military in char- their overseas commitments.Such is one ofhighway legislation, but it would be to theacter than that of France. the tragedies of this post-war era, and such are benefit not only of fast motor traffic but also " The emphasis seems tobe more on the fruits of victory. rhythmic movement and simple games than of pedestrian, cyclist and local motor traffic, Exhibitions provide one opportunity duringwhich would be able, as a result, to use theon formal physical training. the year for the trade, its customers and itsexisting roads with increased comfort and " I was particularly impressed by the im- users to meet, when cyclists may under one safety. portance that 'isgiven to dancing, which roof inspect the products of all the firms " During the next two years priority is totends in France to be regarded simply as a which comprise the industry. We are to bebe given to the improvement of the roadsmeans of enjoyment, so thatits value in denied that pleasure for at least another year.atpointswhichaccidentrecordshave training is apt to be overlooked." 42 THE CYCLIST March, 1947,,

Lincs.The name of the club will be changed to the Barton andDistrictWheelers'Cycling Club and members will be accepted from the villages around Barton. The club chairman is Mr. H. Dent ; secretary, Mr. A. Drury ;treasurer, Mr. S.Coularn ;racing PARAGRAMS secretary, Mr. G. H. Ebbatson ; and captain, Mr. N. See When Wise Girl Ebbatson. The members of the committee are Messrs. IN order that road users and pedestrians can seeWHEN two Land Army girlsgave evidenceat Haddock, Turner, Cammock and Mrs. Crowther. when the " Stop -Go " signalis about to change, Newport Pagnell Police Court on the hearing of a an American inventor has produced a sign with thesummons against a lorry driver for failing to report Suggested Good Resolution words " Stop " and " Go " in illuminated letters.Inthe accident in which one of the girls had been knocked T EICESTER cyclistsare hopingthattheCity a semi -circle round the top of the sign is a series offrom her cycle, which was completely smashed, they A-,Transport Department have made atleastone holeswhichareilluminatedoneby oneasthewere asked about the identification of the lorry.The good resolution for 1947, and that is to do a spot of mechanism lights up " Stop " and darkens " Go,"girl whose cycle was not damaged told the magistrates repair work to the roadway adjoining the tram lines. and vice versa.It is possible to see at a glance whatthat immediately after the accident she scratched theThe lines themselves are treacherous enough and in period will be left before the signal changes. lorry's registration number on the frame of her cycle. addition, mainly due to wartime neglect, the surrounding The driver was fined £i and ordered to pay 14s. costs. road surface is so worn and uneven that a cyclist has Snow -cycle to be extremely careful to avoid being thrown from A 74 -YEAR -OLD villager who lives at Schwandi,Going Too Far ! his machine, particularly at night. inSwitzerland, and has a paralysedright legAMAN who appeared before Leicester City Magis- and only one arm, has designed and builtseveral trates on a charge of cycle stealing, admitted toStarting Them Right " Schneevelos " or snow -cycles for his friends.Thethe Bench that altogether he had stolen 14. machines.TWO Peterborough children, a girlaged 8 and a frame, of the orthodox cycle pattern, is built of woodHe was, however, rather annoyed to see that he had been boy aged 6, holders of " Lucky Tickets " at the and instead of wheels, hand -carved wooden runnerscharged with stealing two cycles in one day. He said Savoy Cinema, Peterborough, were thrilled when they are fitted at the front and rear.These snow -cycleshe had never taken more than one cycle in any one day found that their ticketsentitled each of them to a are propelled by the feet on the level, but on a slopeand there must be " a clerical error." brand new cycle.When the manager of the cinema it is a matter of holding tight and hoping for the best. handed over the machines he presented each child with The local children are finding them very useful, and the WOt .f No Pedals ! a copy of the Highway Code and asked them to under- fact that no brakes are fitted does not worry them inTOFFRE PLOWE, one of the younger members ofstand it before they ventured out on the road. the least. Jthe Grantham Road Club, was the winner of the club's free -wheeling contest by travelling just about zi Keep it Safe ! miles without pedalling. He said the two large bricks, Don't We Know It ! THE cycles of all schoolchildren at Great Yarmouthwhich he carried in his saddle -bag, helped him con-THE monthly road safety and accident review issued A are to be regularly checked by the local police,siderably downhill but rather held him back on the by the Chief Constable of Lincolnshire,after and at the end of each year the school whose pupilslevel run.All the competitors removed their chains giving details of road accidents during November, are found to have kept their machines most roadworthybefore the start of the race, just in case instinct got the says :" The use of fog lights and undipped headlights better of them. appears very prevalent. They are not focused properly and safe, will be presented with a new cycle. and considerable inconvenience is caused to approaching Enthusiasts Barton Club to Re-form drivers." Perhaps one of these days such ill -manners on WEARING leather jerkins and shorts, Mr. C. Smith,THE re-forming of the Barton Wheelers' Cyclingthe part of motorists will be a matter for a police oftheKettering and Yeovil Cycling Clubs, Club was decided upon atthefirstpost-warprosecution, having regard to the increased risk of an and Mr. A. G. Young, of Yeovil Cycling Club, rodegeneral meeting of the club, which was held at Barton, accident when a driver is dazzled. over I6o miles in bitter wintry weather to attend the firstpost-warprize -givingand luncheonheld by Kettering Amateur Cycling Club. On the day following, they cycled back to Yeovil.About midnight on their first day's journey from Yeovil they reached Brackley, Northants, and spent the rest of that night by a blazing My Point of View fire at the local gasworks. A few hours after setting off again they were at Kettering, where they were met by By "WAYFARER " a car which took them the remaining few miles to the reason !I feel, however, that clubmen who regularly Sondes Arms, at Rockingham, where the luncheon wasDeclining Band enter this competition in lateness in the matter of forking being held. IVERY much fear that we who use acetylene gasout their subscriptions might advantageously give a Scunthorpe Polytechnic Club lampsfor our seriousnightcyclingare(like moment's thought to the result of their slackness. Do exponents of the fixed gear) a declining band. My they realise the amount of extra work which they impose IN the course of his annual report at the dinner and fear arises solely from the circumstance that the demand prize -givingofScunthorpe Polytechnic Cycling on the long-suffering treasurer ?Here is an example : for gas lamps is bound to be reflected in the factories, One who keeps the money -bags ofalargecycling Club, the hon. secretary, Mr. J. R. Pulling, referred to and already I hear that there is nothing doing in theorganisation told me the other day that, as last year the activities of the club which were planned for 1947.way of such lamps, since suspension of manufacture was drawing to a close, he had to sit down and prepare He said the club had plans for an open sports meetingduring the war period.Personally, with a " fleet " (and despatch) no fewer than 128 reminders to members to be held in connection with Scunthorpe United Foot-of four gas lamps-enough tolast out my cyclingwho had not paid thesubs. due nearly 12 months ball Club in the summer, and he hoped the meetingcareer-I need not worry, but some of my cycling earlier.Think of the unnecessary labour thus imposed would be very successful.Scunthorpe has had nocompanions who share my preference for acetyleneon the luckless official, oh !ye laggards, think of the sports meeting for many years, although at one timeare inclined to be a bit het -up as regards the future.cost of the postage. itssportsmeeting wasoneofthebest inthe Fortunately, there must behundreds of discarded Some clubs have a salutary rule, seldom enforced, country.The club has at present over 7o affiliatedlamps scattered about the land, and these could beof lapsing membership when subscriptions are not members, and its finances are sound. brought back into use if and when the need for thempaid by a certain date.Such a rule should not be Lucky Children occurred. necessary in a sporting organisation, it seeming to me to be the very negation of the things for which a cycling IINDSEY County Education Committee has decidedNot Far-fetched club stands. Perhaps, however, this " word in season " , to spend £300 on the purchase of cycles for theTHE story told by a motorist who charged into amay cause the bad payers to realise their obligations, use of children in their area of North Lincolnshire house is not so far-fetched as would superficiallyand it may be that, in future years, hon. treasurers who have to travel more than two miles to school. appear.He said that he swerved to avoid a shadowwill be overwhelmed with a spate of subscriptions from Up to now the children have had to get to schoolwhich he thought might be a pedestrian.On moremembers who are anxious to be the first, rather than as best they. could, either walking or getting a lift nowthan one occasion, when cycling at night, I have beenthe last, to discharge their obligations IThat would and again. The committee has set aside £so for allow-startled by hurrying shadows induced by the lights of be a pleasant change, and one in regard to which, ances to those children who already cycle to school. overtaking motor -cars. Itcan be veryalarming. I imagine, no club official would complain ! If there should be a suitable bus service the children And so I believe that the house-rammer above -mentioned would, of course, have to use itinstead of cycling,may well have been telling the truth. Nose -bag Meals but in the majority of cases there is no service. WHATEVER may be said in favour of nose -bag Gad, Sir, What Cads ! Modified Praise meals in the summer loses some ofitsforce 'PROM a leading article in The Times: " The bicycleduringthewinter, when theclimaticconditions, MRS. BRACE, of Grantham, Lines, who arranged A. offersperhaps the best facilities for seeing the usually,are not (shall we say ?)quite so pleasant. the decorations for the Belvoir Hunt Ball, held at countryside, but there is much to be said for the topOn an austere winter Sunday two of my friends put Buckminster Hall, borrowed 22 bicycle lampsand of a bus."Amended to omit the word " perhaps ' into a familiar guest-house in the hope of obtaining a used them to provide a special lighting effect.After theand all words after " countryside," the dictum can be pot of tea to consume with their sandwiches, and were ball was over, as the old song goes, she went to collectaccepted by cyclists.In itspresent condition thisrefused on the grounds of busy-ness. A second and up the lamps and found that all but four had been praise of the bicycle is very modified. third call produced exactly the same result, and, in the stolen.Mrs. Brace says she will have to pay for the end, my pals adjourned to a church porch and ensconced missing lamps herself, and she has suggested that theLocal Colour themselves on the usual stone seat, there disposing people who took them should send sortie " conscience LEADING a draught horse along a busy city street,of their nose-bag meal and doing without a drink. money " to the Belvoir Hunt funds. a man improved the shining hour by whistlingThis sort of experience may be all right in the " cycling Mixing the Colours that well-known marching song, " The Road to theseason " proper (my preference then, and at all times, Isles."Visions of Lochaber and Arisaig and Mallaig isfor a knife and fork function), but it does leave CONFUSION was caused at Grantham, Lines,. when and the Five Sisters of Kintail and the Kyle of Lochalah! something tobedesiredonalessgenialday! iv! the town's new streetlighting system, with itsOn a hoarding round the cornerIcame across an mid -winter. mercury vapour lamps, was switched on.The blueauctioneer's announcement of the impending sale, at lighting of the lamps made yellow lights appear green.the familiar Blossoms Hotel, Chester, of the even more Mouth-watering This caused particular trouble on the stretch of railwayfamiliarSwallowFallsHotel,nearBettws-y-coed. IN connection with a recent newspaper discussion line just outside Grantham Station.As soon as the More local colour swam before my eyes.Later in the concerning the use of Rannoch Moor as a military lights were switched on the engine drivers began today, when reading my newspaper,I found a notetraining area, an interesting sidelight on the nature come into the station at speed, instead of observing the aboutthedeathofViscountessPowerscourt,at of the terrainisprovided by one who is" in the yellow caution signal lamps.When they were askedPowerscourt, Enniskerry, which invoked memories of know." The moorcontains alargenumberof the reason they all said they had seen green lights. my first Irish tour, while an advertisement sponsoredextensive and dangerousbogs.Nearlysixtyyears, Screens are to be fitted to the offending street lamps. by the Scottish Tourist Board inviting all and sundry ago, when the West Highland Railway was constructed to spend Christmas in the Land o' Cakes (there toacross Rannoch Moor, part of the line had to be Badge Wanted enjoy good fires, exhilarating air, and first-class food) " floated " on brushwood and, where the embankment A KEEN collector of military badges has writtenset me a -longing for a trip to Caledonia, stern and did not permit of this form of construction, enormous to the Ramsey (Hunts) branch of theBritish wild. Thus can a stray word bring sunshine-localquantities of ashes were brought from the steel works Legion, offering a donation to the Legion funds incolour-to the gloom of a wintry day, if you are ain the Glasgow neighbourhood and dumped into the exchange for one of the cap badges of the old Hunting. cyclist ! bog to form the embankment.Ineverseethat donshir e Cyclists' Battalion. . railway over Rannoch Moor without feeling a strong Competition in Lateness urge to use it-just as I would love to traverse the Cycle Company's Ball ONE sometimes wonders whether there is a sort ofline from Fort William to Mallaig.They are both" QOME 30o guests were present atthe annualball competition amongst clubmen to be the last to mouth-watering routes.Sofar,in eachcase,the 4"organised by the Elswick Hopper Cycle Co., Ltd., pay their dues to the organisation of which they areroad has been good enough for me, butit would Barton -on -Humber, Lincs. Localcharitiesbenefit members.In this possibility may be found a reason indeed be a thrill to do the railway journey as a change. by sums raised by these events and this year over £1 o for the reluctance of many people to take on honorary And, one of these days-please the pigs! -it shall be was obtained for charitable purposes. jobs-though sheer laziness may be a much more likelydone. March, 1947 THE CYCLIST 43 Aroundthe Wheelworld By ICARUS

"Calling An Sportsmen" themto do what the committee itself proposesMore Leisure: More Cycling to do.The committee will retain its separate TWAS considerably astonished in listeningentity for 1947, for the purpose of mobilising SPEAKING recently at thefirst annual 1to the programme under the above titlepublic opinion in support of improvements at dinnerof thelocalbranch ofthe during the evening of Friday, January 31st,Herne Hill and for the purpose of directingNational Association of Cycle Traders, the to hear a discussion on massed -start racing.public attention to the methods by which suchLord Mayor of Birminghamsaidthat I considered that this debate was particularlyimprovements can be carried out. thousands of people, given more leisure by unfair in that there was no one representing the introduction of thefive-day working the British League of Racing Cyclists in the week, would take to the Open Road, and he studio to put their case.It seemed to meThe Tricycle Association suggested thatit was the duty of traders that the questions were badly framed, and not only to sell cycles but to co-operate in they were answered by those who either did DURING 1946 the Tricycle Association ranthe provision of information about week -end not know anything about massed -start racing five road events attracting 88 entrants.accommodation in the country.The speaker or else were known to be hostile to it.I thinkThe " 50 " attracted 35 entries.The interestadded that there would be a shortage of it wrong policy on the part of the B.B.C.in the three-wheeler appears to be increasing,motor -cars and motor -cycles for a considerable to allow controversial topics of this sort tojudging from the increase in demand for them.time to come, and that the existing army of be debated unless both sides of the case areThe North Midland Region has been formed,cyclistswouldbejoinedbythousands put at the same time.I was not in the leastcateringfortricyclistsin the counties ofreleased for long week -ends by the shorter surprised, therefore, to learn that the speakersYorkshire,Nottingham,Derbyshire,etc.working week. were against massed -start racing, and I haveFor the present season the " 25 " will be held May it be so !The extra leisure provided in Cheshire, the " 50 " on Merseyside, theby the five-day week will be justified if a accordingly writtenaletter of protest to in theB.B.C.askingthatthe Leaguecase" 100 "inYorkshire, and the" 12 " goodly proportion of the people concerned should be given equal prominence in a similarconjunction with the Manchester Wheelers.decide to devote their play -time to cycling, programme. Ihavealsosent RaymondC. E. Green was again elected chairman. which is such an admirable and profitable Glendenning, and alsotheDirectorof method of using one's leisure, and, moreover, Programmes of the B.B.C., a copy of theThe Half Century Club isamethod within the reach of practically memorandum on massed -start racing which everybody. I prepared for the League, rand which was FIVE new members of Raleigh'sHalf submitted to the Ministry of Transport. Century Club have been presented withAire Valley Cycling Club It would appear that the antagonists of thissilver tankards and cheques by Sir Harold new, wanted and most popular form of cycleBowden, Bart.,the Raleigh chairman,in ANEW club has been formed in Bradford sport intend to leave no stone unturned inrecognitionof5oyears'service. The and district called " The Aire Valley their efforts to getit suppressed-but theyveterans are : Cycling Club " (affiliated to the B.L.R.C.). Mr. Ernest Cooke (service department),Regular runs have been arranged, and we will will be unsuccessful.In view of this broad- welcome all intending members and friends. cast was not its title a misnomer ? who joined the company in 1897, and originally taught Sir Harold how to " key up " cranks The Secretary is :G. Mason, 2, Arncliffe James Kain has sent a letter of protest to the Terrace, Lidget Green, Bradford. B.B.C.: on bottom bracket axles ;Mr. Bill Spray " Lasteveningandthroughouttoday(bracket shop), who started with Raleigh in Ihave received several 'phone calls from1895 ;Mr. Walter Bourne (Sturmey-Archer WIRE AND WIRE GAUGES listenerstotheaboveprogramme, whorepairs), who also started in 1895: Mr. H. By F. J. CAMM. 3/6, or by post 19 from in George Newnes, Ltd., Tower House, complain most strongly of that part of aHoperoft(reconditioning), who started Southampton Street, London, W.C.2. discussion dealing with cycle road racing." 1891 and who retired from the company's I would add that I have also sent for a copyservice in July, 1946, of this broadcast and shall comment on it in aand Mr. T. Bradshaw (3 -speed machine), who later issue.In the meantime, I advise thecommenced work with the B.B.C. not to rush in where angels fear tocompany in 1891 and retired tread. in December, 1946. There are now 18 members Cycle Tyres of Leather of the club, all of them with 41,6*. atleast 5o years'service. DURING therubbercrisisDunlops rr experimented with tyres made of leather,In making the presentations but they were never put into general use.Sir Harold mentioned that Dunlops' production of cycle tyres reached ahe himself was within two total of 85,000 a week, but the bulk of theseyears of becoming a member. were used on munition workers cycles and for paratroopers folding cycles.A smaller pro-CyclingisSuch Fun portion were dropped by parachute to the UNDER his pen -name of French Underground Forces. " Ragged Staff," Rex Coley's lighthearted yet in- V"-7. structive writingsare well A R. Haine's Appointment known in both the British ' THE N.C.U. has appointed A. R. HaineIsles and the U.S.A.His as professional promoter at Herne Hillcycling adventures cover a A.. Track.The Committeefor1947Trackspace of twenty years, during Sport were kept fully informed of the offerwhich time he has cycled itt made to him by the N.C.U. and the committeein every county inBritain were unanimous in their desire that he shouldand Ireland. cfee accept the post.He has therefore resigned as In whatever company .(10 . secretaryof the committee and the newRagged Staff finds himself, 91 secretary is Mr. C. S. I. Scott, 19b, Cliftonlaughable complications in- Gardens, London, W.9. variably occur, and the reader 161101( The committee are still of the opinion thatwill here get full enjoyment the best interests of the sport would be servedfrom these amusing remini- STIRLING by the setting up of the N.C.U. of a completelyscences. There is a foreword CASTLE, separate organisation on the lines of the schemeby F. J. Camm. The historic castle they have already laid down, and which has With 31 illustrations by t hat. defended the been published in this journal.The com-A. J. Charles, the book is Pass to the Highlands mittee has, however, performed a very valuablepublishedbySkeffington task.They have shaken the N.C.U. fromandSon,Ltd.,55, Pont its lethargic and torpid slumbers and forcedStreet, London, S.W.I 44 THE CYCLIST March, 1947 CyclinCharacters

SomeInteresting People I HaveMet THE cycle trade and pastime includes A Nasty Spill By R. L.JEFFERSON as many-if not more-cranks and SuddenlyI heard acrack and feltthee: eccentrics as any sport I know.It is handlebars go " limp " ;I realised the steer-, perhaps onlynatural,asoursissuch a Presently the dealer came out and we hading column had broken. ItoldBill,- as", unique pastime ;it is travel and sport com-a long chat.I told him of my interest incalmly asIcould, and putting his hands bined, and has a history of well over athe history of the wheel, and he sold meon my shoulders he started totread back century. a few early cycling books and catalogues. that terrible gear.I had to try to counter- It was my very great pleasure before theHe told me that his own hobby was collect-act his swaying as best I could.Luckily the war to travel daily by bicycle and call oning old newspapers, and he took me upforks were well raked, and this kept us going. all the people connected with the trade into hisflat over the shop and showed meBill managed to slow the machine down to London and the Home Counties. his collection.He had No. I of The Times,about' evens," when suddenly we snaked. Back in the 'Eighties Telegraph, Spectator, etc., and all were inThat's all I remember until being picked up. 1 One wet and miserable dayIcycledbeautifulcondition. Some ofhispapers My injuries were two broken ribs, a torn through Blackwall Tunnel and entered thewere well over three hundred years old, andinstep and numerous cuts and bruises.Poor yet they looked asifthey had just comeBill lost the sight of his right eye and had maze of streets which make up London'soff the press.At a later date I was able tomore thanhisshare of bruises and road East End. My last call was in a street whichsend him a few very old papers, and we burns. at one time had been of some importance,corresponded on our respective hobbies. Weeks later, when we had recovered and and the cycle shop was old, the proprietor were examining the tandem, we discovered seemed,ifanything, even older ;he kept the door on a chain, and on answering myA Trip on a Tandem that the steering column was 20 gauge plain knock he inquired my business.Inviting Just after the 1914-x8 war, when cycles steel ;how it had stood up atall was a me in, he apologised for the light --a candleand accessories were even scarcer than they mystery to me.I took the forks to my local in a bottle-and explained that he had hadare to -day, a friend and I decided to buy amaker andhe brazedabutted tandem a disagreement with the gas company andsecond-hand tandem.A new one was outcolumn into the crown. We reassembled the they had cut off the gas." Of course," heof the question ;they just weren't beingtandem and sold it cheaply. said," a young fellow like you wouldn't made. Shortlyafter,Billblossomed out on a know any of the old timers like I do." I We scanned the columns of the cyclingbrand new A to Z French welded cycle, and mentioned Sparrow and Timberlake and apapers week by week, and eventually whatwent into serious training for the first " 50 " few others, and he brightened up consider-appeared to be a suitable machine turnedof the season. He wore glasses, and his right ably. He explained that he had at one up.I took a day off from work and cycledeye was replaced with a glass one. We rode time back in the 'eighties been one of theover to Walthamstow to inspect the tandem.to the eventatasedatepace, andBill largest cycle manufacturers in London. HeIt was a path racer and very light,it hadchanged by the roadside.I proceeded to my asked me to follow him into the basement ;26in. wood rims for wired -ontyres,and appointed place to hand up drinks. Bill this extended right underthe road, andonly one brake, a short pull-up to the frontdid quite a respectable time for those days, there were very large racks full of castingswheel.The machine had Ain transmissionand wis very pleased with himself, as he covered with dust.There must have beenand was unique inseveral respects.Thewas placed second in the handicap. several tons of these parts, all of them wereseat pins were held in place by expander bolts, the left-hand cranks and axles wereContinued Bad Luck for solid-tyred safeties and tricycles.There I turned his wheel round for the low gear were also one or two complete solid-tyredin one piece and the chain wheels and right- hand crankssplined on totheaxles.Itand we started for home. When we reached tricycles, a couple of ordinaries and a few Chiswickitwas afternoon, and there was safeties, and one of these latterI boughtweighed only 421b., which was certainly very light ;there were three spare chain wheelsplenty of traffic.The buses then had open from him. and a number of accessories.The pricetops and solid tyres, and someone on one of r A Racing Veteran was £15, alotof money in those days.the bus tops threw a large apple core over- In another part of London I was wheel-However, I took a chance and bought it.board.It struck Bill's glasses ; he lost the, ing along a main road when I noticed aI rode the tandem with one hand and trailedsight of his other eye-a cruel bit of bad' name over a garage. The name was familiarmy single home with the other.I lived in luck. to me as that of a famous racing man ofBayswater then, and it seemed quite a long But Bill wasn't done with cycling yet.I, way.I found out later that the gear ofborrowed a tandem and we took many a a few decades ago ;I found him under a week -end trip -on Lagonda andintroduced myself. Hethe tandem was 108. it. He had an uncanny climbed out and we startedto yarn ;he In the evening I rode over on itto myway of telling me where we were ; he always had certainly aged since I last saw him, butfriend's house ; he seemed very pleased, andknew when we had passed Barnet Church his memory was still good.We appearedcomplimentedpieon my capture. Weand were approaching the Old Man's," a to be talking a language quite foreign toadjustedtherearseat and tried outthe popular cyclists' resort. the several mechanics in the shop.Presentlymachine round the outer circle of Hyde Park.Recompense he led me outside and across the road,Returning home, we made some more adjust- ments and put the machine in thorough order. Some few years later I went abroad for through an alley, where we entered an old nine years ;whenIreturnedInaturally stable, and there on the wall was the frameWe then decided to go to Dover and backlooked up Bill, and found him a successful of the cycle he rode years ago with suchon the following Sunday for a real test. French polisher, employing twenty men.It success abroad.It was his firm belief that would seem that when we are deprived of that machine had travelledfaster unpacedA Good Start one of cur faculties, Nature intensifies ,those , than any other machine had ever done. On Bill was waiting for me when I turned upremaining. the floor of the barn was a watering can,at8 a.m.that Sunday morning ;we got Just before this last war a friend of ming,- and he told me quite simply thatit wasgoing, and soon left the suburbs behind. Theknowing I had a " nose " for finding difficult' his custom to water the frame from timeDover Road was not as smooth asitis to-things, asked me ifIwouldget him to time.In this way, he argued, it wouldday, and some of the surface was roughbottombracketaxleforhis" Centaur eventually disintegrate,and he would bemacadam. As we approached the top ofFeatherweight." This machine had not beeti sure that no other person would ever ride it.Wrotham Hill I warned Bill of the gradientmade for over twenty years then. and the surface. I went tf$ The "Euclidia " The road then used toa dealer I knew in S.W. London and aske0- go right through Wrotham village, and therehim for theaxle. Opening a drawer, In one of the Medway towns of Kent Iwas a dead left angle turn inthe villageproduced one straight away, and added that)' called one afternoon on a very old -established which had to be negotiated at walking pace.he could supply axles and parts for Rovers, dealer.A traveller was engaged with theI told Bill about this, but he didn't takeSparkbrooks, Raglans, etc.,all,ofcourse, proprietor, so I waited.Strolling throughmuch notice ; he looked over my shoulder andlong obsolete, yet he had very little up-tO:- the yard at the back, I saw, hanging up, a saw the village over a mile away." Let herdate stcck.It seems he managed to make verywell preserved" boneshaker " ; Irip, we can easily pull up before we get alivingsupplyingpartsandrepairing noticed it was a " Beck," of Lister Works,there,"he said.Like a fool,Itook hisobsolete cycles. Holloway,oneoftheoldestmakersinadvice and soon we were flying down the Itis people like the above and hosts of England. There were alsoseveral ordin-hill. Presently we reached our pedallingothers I have met that add so much to the aries, and a solid-tyred safety, which latterlimit on the 108 fixed gear, and goodnessinterest and enjoyment of the pastime, and was the unique " Euclidia," the frame ofknows what speed we were doing.It mustthey help in their; way .to make cycling the which defies description. have been well over 4o m.p.h. grandest of all games. March, 1947 THE CYCLIST 45

Repair /Cs WITH THE Tubes "No other tyre VULCANIZER.. Repair Synthetic Tubes by vulcanizationsay the authori- will really satisfy ties. The AUTOTHERM Vulcanizing Outfit is complete, repair and heat unitsin one, everything provided but match for lighting.Punctured motor cycle tubes,footballbladders, hotwaterbottles,etc.,also me now repaired. By the AUTOTHERM method the damage is sealed, reinforced and vulcanized in a few minutes at the roadside or elsewhere. It's simple, scientific and inter- esting. Young cyclists are fas- cinated; their elders delighted. Notethelow price. Sold by any good dealeror write tous for name ofstockist Enquiries invited from the Trade. ifyou havedifficulty. WILLIAM FROST PRODUCTS Sole Distributors: U NI -GU N LUBRICATING EQUIPMENT LTD., 2, South Audley St., London, England. Telephone : GROsvenor 4551.

APEX The World Famous 'SUPERLITE'BAILEY'S CELLULOID PUMP `SUPER' 15 : BLACK PUMP IS ; ' BLACK Thick Celluloid Steel Lined Beautifully Polished Celluloid Covered

Light of Weight Lining is Solid drawn but of cartridge fashion, the ends being solid with the barrel. robust construction Cannot warp nor leak. ' SUPERLITE '15in, CELLULOID (with A 19 BAILEY'S'SUPER' (Steel solid drawn brass -ri lined and Celluloid 5/6 plunger tube) each covered) 15in. each 'LAST WEL' CELLULOID BRASS PUMP,Nickel (with steel split Plated or Black enamelled plunger tube) 15in. q (withsteelsplit each plunger tube) each-r APEX PRODUCTS Are in use in every Country in the world. Theyareknown and appreciated for theirreliability,long service and efficiency in their job of inflating tyres. Labour and materials are still very much restricted ; consequently supplies of pumps are scarce !If you are lucky n BESTTODAYrest° * STILL BETTER TOMORROW in owning an Apex Pump, treasure it. MADE BY APEX INFLATOR Co. Ltd. ALDRIDGE ROAD, PERRY BARR, BIRMINGHAM 22B 46 THE CYCLIST March, 1947

Herculesnu[nMODELS INTEREST COLOUR STYLE,k, Jo.a&fddy?,cia You remember the famous Hercules Road -Record -Breaking models of pre-war days.Since then,war -timeandpost-war lessons of high precision manufacturehavebeen added to record -breaking experience in producing the finest bicycle built to -day.

Hercules ,mA THE HERCULES CYCLE& MOTOR CO.LTD., ASTON, BIRMINGHAM . March 1947 THE CYCLIST 47 Ihavebeenaskedthat question in many quarters, Headlights and itisa difficult one to T DO not like the dazzling headlights, and far too answerbecausethein- A many motorists who dip as an act of courtesy would Wayside dustry itselfis not atall greatly improve the value of that gesture if they would see that their headlights were correctly adjusted, not certainofthefuture ofmerely for their own convenience but for that of the supplies or the stability of I say these things as the result of 141 wages. The labour force isoncoming traveller. It,tilli recent experience, yd. I do not want to put the blame , also afactor,the present Thoughtsshortage militating against too heavily on the car oirner because I think he is very highestoutput,and much the victim of the lighting equipment manu- plo the facturer.That is where the criticism should arrive, By that condition has a veryfor we are too apt to blame the driver who after all III big bearing on the costs.(and provided his lights are properly adjusted) is only ) 111.11,,finiiip My own impression is thatusing the equipment of the car.The serious effects of F. J.URRvI , the price of the basic bicycle dazzle have not been eliminated to the extent we had .,,- (£3 tgs. gd. pre-war) willhoped ; indeed, the more powerful beam of modern lamps, remain between km andeven when dipped, are an annoyance if not a danger to ,-e- £ s,includingpurchase oncoming travellers.Motorists themselves say little tax, and that a good classabout it in public places, but if you listen to their private machine, accordingto complaints you will find they are at a greater disadvantage specificationand equip-than we cyclists, due of course to higher speed and ment,will varybetween windscreen reflection. In the aggregate they want an £16 and £25. improvement in head lighting for the purpose of over- coming dazzle as much as we do --or so they say-and I think it is up to them to air their grievances in such a We Are Fortunate way that the lighting equipment manufacturers must take IT seems a big price to notice ;for I will not believe the present disabilities J.pay for a bicycle;yet, cannot be reduced, if not completely eliminated.I ..- andmarkthis,weare have found, when meeting a particularly bad specimen merelyrevertingtotheof dazzle,that by shutting an eyefortheshort pricesrulingduring the - period of discomfort, and opening it when the glare has mid -nineties,when thegone, relieves that black -out patch of nothingness into cheapest machine costr4 which you wobble on such occasions.Dazzle won't CC guineas, and in s896 I paidstop me night -riding, but it does add to the journeys i!!!' kz6 for an Osmond, and that unnecessary sense of irritation. that justaframeand wheels, no hub gear, brakes or mudguards.And thereMy Daily Journey was no purchase tax then, THE daily journeys come and go and have their little which to -day accounts for adventures, for 15 miles of town and suburbia are approximately 24 per cent. bound to bring one in contact with the varying manners on what would otherwise of, many people.I get along quite well, and not being be the retail figure.How- in any haste never seem to be in any danger.It is, I ever, it is useless comparingam certain, the fast folk who cause trouble, fast that is present-day costs with thosein their degree, for not only motorists but cyclists and of so years -ago, for at bestpedestrians become affected with the desire to hurry they are only a matter ofand thereby break the rules and are often a danger to Falkland Palace , interest. What we shouldthemselves and other people.Only a few hours before be doing is to realise thatwriting this paragraph, a youngster on a bicycle crept Neshire. the bicycle is one of the feWbetween my rear wheel and the verge without my know- lie home al dames1, articles in wide use that hasledge, and when the green light came up tried to jump only doubled its cost.Intne for the corner.I could not move outwards because a sad uitited many Mmes the better type of machine car was alongside, and as there was no room for two of us gani ,queert of Searc thecomparisonsbetween abreast I gently elbowed (an old riding trick) the young pre-war and to -day's figures man on to the pavement and then stopped in an endeavour are certainlyin favour ofto correct his conduct for future use.But he was not the buyer, for one could not " wearing me " as a monitor on manners, and told me expect very much for £8 in 1939, and Liz LOS. waswith adjectival emphasis that I was the type of old idiot It is Badly Needed not an outside figure for the best type of machine.So who ought never to be allowed out, etc.Such speci- T WAS glad to read a leader ina technical journal taking it all round I think we cyclists are fairly fortunate mens of riders are almost bound to come to grief .1. criticising the present type of battery lamp, front and have little enough to criticise on the cost question._sooner or later, and itis a pity some kind of gentle and rear.The plaint was timely, for the rubbish offered It is the good goods we want, for it is demonstrated thatcorrective cannot be applied to them while they are at a big figure of cost seems to me an imposition in so tarthe real value to any and every type of rider is in thestill whole and hearty.That is the only case of really that you cannot buy anything better.Cycle lighting betterbicycle. -Ihave known thisforyears,and bad cycling .1 have witnessed up to this winter day, so I has gone backward as far as the battery lamps are remember I am a utility cyclist riding over 3,000 miles ado not think the general conduct of the wheeling folk concerned, and personally I get a bigger load of trouble year to and from work. This year of 1947 we shall see ais nearly so bad as some motorists declare.On the in illumination than any other component concerning change I hope, and some of the promises made by theother hand, the car drivers too are mainly decent ; the equipment of the bicycle.Apd there is no needindustry during the war will be implemented, for theit is the young man at the wheel whose impatience is for this worry if we were offered the right type of casinggrade must get going if a successful show is to be held inapt to twist his manners ;he cuts in, pulls up sharply for our batteries instead of the cheapest and flimsiestthe fall of the year. Personally, I hope that will occur- immediately after passing (a bus drivers' trick, too) form of thing possible to make.A stout brass case with both the supply of high-class goods and the show-forand frequently gives you less elbow room than he could. proper contacts to lamp and battery will overcome allthe former will prove my contention that cycling is I am used to Mich occurrences and prepared for them ; the many defects we are now made to suffer.Of course, very much alive in the minds of men, and the latter butI can quite understand that the nervous cyclist designers (who do not ride bicycles) tell me I've a bee will spur forward the production of those many im-abjures town riding whenever possible.But, generally in my bonnet on the question ;but then they haveprovements in machines and their equipment, which speaking, I think road conduct is slowly improving, had no experience of the first battery lamps of aboutI know are awaiting the opportunity of coming on the fortheprocess seems discernibleinthe accident 30 years ago, made from sheet brass with sturdy contacts returns.Yet we have a long way to go before the and retailed at 8s. 6d. each.They lasted many wintersmarket. manners- maketh the man " is firmly in the mind of and were most reliable.Now most of us who ride daily every individual who takes to the road. use new lamps every season, and even then, if they are subjected to stormy trips and caked with mud, they often The Urgency of Roads refuse to function and require a lot of persuasion toT THINK every regular road user agrees that the This is the Truth make them carry out their duties.At the moment,A major transport problem now is the lack of road OFTEN enough people who have not seen me for a battery lamps are the worst equipment on a bicycle, and space in certain areas, and this trouble will increase few weeks ask how it is I look so well. I suppose it is not possible to buy anything better. Go over toconsiderably in the very near future.Authority will the tan of the weather sticks and the outdoor hours leave the dynamo,"Ican hear someone say.WhileI their mark, for I'm not conscious of feeling well because can buy my light I do not intend to work for it ;andbe obliged to meet it soon, and the longer the work is that surely should be the common lot of all decent people. besides, even dynamos are difficult to obtain, for thedelayed the less likely itis that proper planning willWhen I say that my travel method is the main reason for supply is strictly rationed to the dealers.Give us agive us the necessary road room, and also preserve themy fitness I suppose most of these friends, even if they really good battery lamp and many of our lighting amenities.Personally I should hate to see some of ourbelieve it in part, feel it to be an exaggeration in total.Well, 'roubles will disappear. main roads rendered to motorwayi . pure and simple, I don't.I am of the opinion that the health and to think that the curly lanes of Devon or Warwick-value of cycling is not merely underrated, it is almost shire would be redesigned for the use of fast traffic isunknown.Medical men do not ride in these days, and The Price Oueshon unbelievable. Surely we do not need tosacrifice therefore have no first-hand knowledge of the exercise, WE are now becoming used to the reign of neweverything to speed and impose a drear prospect on allwith the result that their opinions are given-if at all- prices and do not exclaim quite so . violentlytravellers because a comparatively small proportion ofin a vague and uncertain manner.I am not blaming as was the case a year ago. Then many of us expectedthem are in a hurry ?We -have proved we can makethem, being busy men with little leisure to burn ;but the cost of things we desired would dropthe war.big arterial roads tidy, often at the expense of theirit does seem to me a pity that a simple thing like cycling was over and it merely needed the swing of our factories one-time loveliness, butIthink . no countryman or should not be quoted as a means of acquiring and retain- to peacetime production for the shortages to be madetownsman with a sense of country love and lore willing health, and that condition of bodily and mental good, at a lower retail figure and of a better qualityagree that such routes preserve the dignified beauty offitness which preserves a youthful outlook.The fact than the products we had to use during hostilities andthese lovely islands.They are a means to an end, is,I suppose, that cycling is not fashionable and the actually were then thankful to get.But it didn't work necessary perhaps in these days of urgency, but certainlypriggishness in our make-up suggests a preference for the out like that. Excessive overtime had appeared, and the an invasion of the old time amenities of our islandmedicine bottle rather than the exercise.But what standard rate of wages had only been maintainedhome. So we come back to the old question of motor-delight people miss.To feel fit and well is a magni- during the war because of overtime and the paymentways, not the translation of our present roads to speed ficent thing ;to acquire and retain that condition as the of generous peacetime rates. So wages went up and, tracks, but the actual building of motor highways for result of a pleasant pursuit is idealistic, and here in cycling as wages are the main charge in bicycle building, the service of fast traffic.It will be the system sooner is the offer and the certain result.I have no doubt bicycles, replacements and equipment went up.And or later, and would be better tackled now before theabout it, for the pastime is not merely the background the shortages were not replaced; indeed, the situation destruction of beauty of our roads and lanes is sacrified of my enjoyment of life, it is the healthiness of life itself. in that respect has been worse, due in a large measureto pressure of speed. We hear little about the matterMy own theories on this question of cycling and health to the export drive --that urgent call for bicycles fromin these days, for the simple reason, I suppose, thatare based on constant experience, and if I made them countries far worse off than we were and are, in thelabour and material are in such short supply that the public property I have no doubt medical friends would matter of supplies, to say nothing of the national needprojects in the minds of the M.O.T. are of the longlaugh and write me down as a crank and fanatic.Nor for obtaining credits abroad.In that respect the cycleterm variety ;but I do think that important Ministrywould my ignorance allow me to debate the matter with trade has done, and is doing, a fine job of work, evenshould give to road users an outline of the schemesthe professionals, for I presume they would quickly though it may be a little difficult for some of us tothey favour for the purposes of debate and criticism,count me out in the detailsI have no intention of reconcile ourselves to the conditions imposing on usfor I believe the huge majority of people want beautydisclosing.I only know for certain that I'm fit and such limited purchasing facilities. The point at issue infirst, even though they recognise the need for roadhealthy, and a jolly happy human, and that the combina- this paragraph is :what will be the price of bicycles ? room. tion is mainly the direct result of regular cycling. 48 I HE CYCLIST 'March, 1947, CYCLORAMA H:Ey Ethelred the Unready, dated 1oo4, the will of Wulfric Spot, Earl of Mercia, various documents relating to the old rights of the borough, some papal bulls, and Henry the Eighth's grant to Sir William Paget of the abbey possessions. My old native town will be proud of these historic possessions. Along- side the modern breweries there are still the crumbling ruins of the abbey walls. Cycling Club Secretaries are Busy SPRING and summer runs ahead-func- tions to organise-dilatory members to be rallied to the club standard-and all kinds of arrangements to be made for the happi- ness and welfare of the club members during the coming sessions.I have been talking to some of the hard -worked secretaries lately; and, as ever, I greatly admire their continuing enthusiasm, their desire that the members should be catered for properly, and have good times.Members do not always appre- ciate the work of a secretary.He is often a " back -room " boy ;but he does yeoman Hitckarn, work in keeping the club flags flying. kainglems\ iwe Old Idords lke A Joy to Come I,,uclu.r.dkodosady gormd.d THIS summer I plan to have a cycling trip in those delightful counties of Radnor a'AR.4b444," and Montgomery ...those unspoiled, fas- cinating counties where, before the war,I The " Half -century Club is living in retirement at Eastbourne, and ishad such enjoyable tours and made such good fit and well.The son is no stranger to thefriends.I remember that Itook train to isan organisation connected with West Country, and in Bristol will be on veryLlanidloes, in Montgomery. . and from THISthe Raleigh Company, and five newfamiliar sales ground. theredidsomedelightfulridesthrough members havejustbeen presented with magical country.Little Welsh farms, where silver tankards by Sir Harold Bowden, Bart., Springis On the Way folk spoke the Welsh language ; the hillsides, the company's chairman, in recognition of THERE is always a first moment when wecovered in September with rowan -trees gor- 5o years service.I understand that there suddenly realise that the long winter isgeous with blood -redberries ;mushroom - are now 18 members of the club, all of thempassing, and that spring is round the corner.gathering in the misty early mornings ; and withatleast5o yearsservicewith theIt came for me this year as I travelled uplittle inns where, at night, the riding over, company.This isa great and remarkable bytrainfromSouthampton. The sunone could sip ale and talk of the ancient record, and it is good to see such length ofstreamed through the carriage windows ;inglory of Wales, and the deeds of her ancient serviceso suitably recognised.In makingthe fields some lambs skipped joyously bychieftains in the days of grim and sanguinary the presentations, Sir Harold mentioned that their dams ; and there was that indefinable border raids. . he himself was within two years of qualifying" something " in the air . . . that " some- as a member of the club. thing " which makes the errand boy whistleThere's Always the Bike even more vigorously than usual, and which DURING those worrying days when it, The Cycle Show Comes Back ! causes even the tired business man to admit seemed possible that we might hdv'e T EXPECT that, like myself, quite a numberthat life is worth while.The blackbirds areto endure another " General Strike," as in -L of people connected with the cycle tradevocal each morning, the daffodils are piled 5926, I heard many conversations about ways experienced a thrill when they read that weon the barrows of thestreet traders, andand means of transport to work should the were havea cycle show again ;whataltogether we may know, and rejoice, that the'buses, trams and trains fail.And, of course,. memories that announcement conjured up!queen of spring is about to ascend her greenthe great solution was the bike!" Oh!I Veterans recalled the old Stanley Show ... throng, and depose the grim king of winter,shall just ride the old cycle down, starting and I myself had thoughts of many shows, of who has reigned too long. early, and I guess it will be quite good fun." the hectic and exciting work of getting every- That was typical of the comments I heard thing ready for the official opening . . . andRoad Safety Teaching in offices and warehouses and shops.And nobody who hasnot had charge of an ANY of the councils, and many of thehow good to know, that, in the event of the exhibition can realise the snags,thelast- educational authorities, are doing excel-old 8.15 not running, there is the bike wait- minutedifficulties, with which the jobis lent work in connection with road safety... ing to convey us to our desk, or bench! surrounded.But, in my experience at least,in making known the Highway Code, and inAnd asto" good fun "-well, those who everything is always O.K. " on the night,"- inculcating the right ideas into the minds ofhave been lucky enough to be able to ride and when October rolls round and we havethe young.But there isstill much to beto work over the years know how good and to tackle the old familiar job again, I expect done.I am still rather appalled at the care- exhilarating the exercise can be.Yes, there's that all will again turn out well.... And Ilessness of children with cycles ;needlessalways the bike! trust that we shall stage a show worthy ofaccidents happen every day, and I feel that our great industry, and show the world justmore intensive propaganda is wanted amongA Day in Coventry how virile, and ingenious, the British cycletheschools.From talks with teachers,I IT is difficult not to think of bicycles when industry is.The venue will again be Earlshave formed the conclusion that not all of in Coventry, and recently I spent a day Court and the actual date of opening will bethem are aware of the urgency or the vitalin that brave and blitzed city.It was a cold announced late,.. character of the problem. and chilly day, and the keen wind hleVi across those tragic bombed areas . . . but I " Tiny " Holmes Returnsto Dunlop " Beeropolis "-and Ancient Days sensed a great and brave spirit in Coventry: long and very strenuous work with BURTON -ON -TRENT is an ancient and itisacitywhich, overtheyears,has AFTERTyre Control, H. J. Holmes has rejoined famous town.Is it not the home ofweathered many storms, and seen many his old company, Dunlop, and takes up theour national beverage ?Do not its casks gochanges.Its cathedral, when rebuilt, will postofregionalmanagerforthewestforth to the far ends of the earth ?But itbe a focal point for all kinds of activities region,succeeding" Archie "Cochrane, is a town steeped in English history, and Iand endeavour, and when Coventry's scars retired after over forty years good servicewas intrigued to read the other day of aare healed I predict that she will add new with the company." Tiny " isthe son ofsplendid gift to the town by the Marquis ofglory to her rich past . . . and one may be H. E. Holmes, who spent long years withAnglesey. He has given a collection of mostsure that the cycle will continue to figure as Dunlop, and who is well remembered (andvaluable documents relating to the ancientone of the products which send the name with affection) by a host of friends." H. E."abbey, which include the Charter of Kingof Coventry around the world. FOR THE MUSIC LOVER AND SPARKS' DATA SHEETS HOME CONSTRUCTOR MAKE MONEY IN Providefullconstructionaldetails, Shorthand SUPERBLY REALISTIC REPRODUC- and full-size black and white prints TION of RADIO and RECORDS, enable of Tested and Guaranteed Designs. YOUR WORKSHOP the THRILLING REALISM of the CON- SETS of CLEAR (70NSTR UCTION AL CERT HALL to be obtained in your own ANOTHER NEW CIRCUIT DIAGRAMS and instructions for home. Amplifiers, incorporating technical THE UNIVERSAL.FOUR. A 3 -valve in 24 hours? BUILDING YOUR OWN advances not hitherto made available for Plus Rect. T.R.F. A.C./D.C. Set.Ma, home construction, 3 or 7 watt models, and waves. fine volume and quality. Com- (1) TOY, MODEL or WOOD- a Supertiet-T.R.F. Unit designed for high pact and very efficient, 'Impossible!' thought Mr. J.A. E. WORKER'S LATHE, 3'6. quality reproduction. Blueprints for these Goss, .5 l High St., Brecon, South Wales. (2) Power or foot treadle drive FRET units,givingfullcircuitdetailsand THE. TINY TWO PORTABLE. Med. JIG SAW MACHINE, 3/6. waves.51 x 51 x 51in.Self-contained (3) Ball bearing Table Model CIRCU- constructional data, 2,6 each.S.A.E. for Aerial. Speaker and All -dry Batts.: Then he learned the complete theory 01 LAR SAW, 2,'6. catalogue, including details of high quality local stations on speaker for " Indi- Dutton Shorthand by po t,in lust under (or 81- for the three.) Pick-ups, speakers and baffles available. vidual Listening," 22 tours study ! ALL these well tested, simple machines All equipment demonstrated ALL -DRY 3 -VALVE PORTABLE. can be built EASILY from READILY at our showrooms. M,Lwaves,Self-cmitainedAerial. BeforeIattempted Dutton's ',writes OBTAINABLE PARTS AND Speaker and Batts.Size 9 x 6 x 4in.; Mr. Goss,. ' I had unsuccessfully tried to MATERIALS ONLY and will turn out CHARLES AMPLIFIERS, LTD. powerful signals. learn shorthand and am amazed at the 101 Saleable articles for the shops and MIDGET1 -VALVE - PORTABLE. market. Prompt posting. Parts stocked, All -dry Batts., ML waves, 9 volts H.T. time in which I have picked up the 1E, PALACE GATE, Good 'phone signals. principles of the Dutton system, since I P. M. BARIIAM, Les Buttes, MIDGET 2-VALVER. All -dry Batts., had really given up all hope of learning Torteval, Guernsey, C.I. KENSINGTON, W.8. Med. waves, 9 volts H,T., good range. shorthand.At first the timing on each (Publishing shortly-Sig profitable side- 'Phone: Western 2350. A.C. D.C. MIDGET PORTABLE, lesson looked impossible to me, but I lines to make in thd workshop.) (One minute from the Albert Hall.) M L waves. 3 -valves, -plus Rect. have seen that shorthand really can be COMPACT TWO. " S.TM L waves.RAIGHT" (Batt.) learned in 24 hours or less.' 3 -SALVER. (Batt,) Med.-waves. ELECTRIC ENGRAVERS.-Powerful THREE -VALVE T.ILF. SET. (Batt.) *Original letter, Student Record Card and instruments incylindricalcase, on M L waves. Good range and strength, many similar letters available for inspection. standwithspring attachment and FOUR -VALVE T.R.F. SET.(Batt.) switch.Suitable for dog collars, tool PERSPEX As above but with. Push-pull Output. All the rules of Dutton Shorthand, the marking, etc., 4-6 volt model.price andclear, A.C. QUALITY .2-VALVER. ML 55/-A,C. Mains model, 200-240 volts, Perspexcoloured waves. 31 watt output. A popular set. system designedforease of learning, 75/-, postage 1,'-. PerspexCementand Polish. A.C.-TILBEE-VALVER. (Plus Rect.) are mastered by aperson of average T.R.P. Circuit. Range and Quality. TELEPHONE SETS,comprising 2 Took, Plans.Instruction books, AA% St'PERHET. 3 Valves,plus intelligenceintwelve2 -hourpostal G.P.O. hand phones, 2 bells. 2 pushes etc. Rect., S., M,. and Long waves. lessons. Thereisthen nothing new and 80ft. twin wire.Price 65/, post A.C'. 31 WATT AMPLIFIER. free.Single instrument, 25,6. Ideal for P.U. 2 Valves, plus Rect. to -learn, butpracticeisnecessary to Send3d.andlongS.A.E. AA'. "8 -WATT AMPLIFIER. Neg. reach dictation speeds. WIRELESS HEADPHONES, 12/6 pr. forbooklet" PlasticHandi- Feed -hack. P.P. Output, 5 Valves. BATTERY CHARGERS FOR A.C. TWO -VALVE, AMPLIFIER. Batt. Many people, doubtful of their ability MAINS. FOR CHARGING 2 -volt crafts " and fullprice lists to : THREE -VALVE Ditto (P.P. Output.) accumulators at amp. Parts with All Abe above 2/13 easda, plus stamp. tolearnshorthand,havesucceeded diagram, 12/6. Complete. 21/6. Postage with theDutton system and become 10d. PLASTICS -HOBBIES AA'. QUALITY RADIOGRAM. De- fast and accurate writers. FOR TRICKLE CHARGING CAR signed for Quality rather than range. CELLS, parts with diagram. Output & MODELCRAFT 8 Watts. P.P. Output. Neg. F. B.. 3'6. For fuller details and a free trial lesson set,For (Dept. 2) A.C. D.C. PORTABLE AMPLIFIER. Ira cells, fg/ivet711,,r. 360-8amp, 6-8 Watts. P.P. Output. Neg. F.'B. 3 8. without obligation,tear out and send 55/i.O. West Laith Gate thisadvertisement,withyourname IMPORTANT SWITCHBOARD METERS,A.C.- In - additiontoofferingthe Finest and address, to :- D.C. N.P. cases, 1r dial.Any read- DONCASTER Constructors'Data Sheet Service in the ings up to 0-25 volts, 0-25 amps.Price British Isles, I can now offer an Addi- 15/6 each. tional Service in the form of Speedy Supply of all Parts, Valves. Coils and Dutton One -Week BOAT MOTORS, low centre, wound PURCHASE OF SUPPLY CO.'S WATT- Speakers for all my Data Sheet Designs. field,high-speed, weight18oz.Size HOUR METERS. Comprise 230 volt disc Service 1007;, Plus. 5in.xllin.xgin.Well made-No motor on frictionless self centring bearings. Shorthand Rubbish.Price 26/-. post paid. 6 dial precision gear trains giving ratios Many other Data Sheets mailable. up to 100,000 to1. Electro-magnets on Stamp with order or fog -list. laminatedcores wound 1,200 yards L. ORMOND SPARKS (MP, Dept. PM3, 92-3 Great Russell ECONOMIC ELECTRIC CO., enamelled copper. Powerful permanent 9, Phoebelh Road, Broekle3, S.E.4. 64,London Road,Twickenham, magnets,vernier adjustments,etc. A Street, London, W.C.I beautifully made instrument readyfor 'Lee Green 0220. / Middlesex. Tel.:POPesgrove1318. use to check power consumption or for its invaluable components. 10/-,plus 9(1. postageunder money back guarantee. W. & S., 11, Hawley Creseent, London. No Callers. MATRICULATION N. W.1. HIGHSTONE UTILITIES chf.itioakMaster the Piano Introducing Ourselves -- CRYSTAL SETS O. latest Model is Easily, Quickly, Enjoyably a REAL RADIO Unless you have matriculated, you RECEIVER, which To learn to play heautiMily is and our First Product isfittedwitha cannot even be considered for many of easy- with proper hashing PERMANENT the really interesting and profitable Even if you start at middle CRYSTAL appointments. Why needlessly handi- age not 'mowing a note.I DETECTOR. capyourself and go throughlife CAN TEACH YOU to play WHY NOT HAVE By POST.Sun - A SET IN YOUR watching other people winning success really well. clear, Fascinating Lessons, . using OWN ROOM OR and security ?Whatever your age, ordinary musical notations, no freakish SAILOR SAM'S AS A STAND-BY ? you can uow prepare for the all- methods, enabling you to read and play -9;8, post 88. important Matriculation Examination at sight any standard ousted com- PERMANENT at home, on "NO PASS-NO FEE " position.My class is seldom less than DETECTORS,2/6, terms.Write now for our valuable 2,000pupil/. Ihavetaughtover postad, 72,000 daring 42years andI CAN .0003 Pre-set Condensers, 2/-, post3d " GUIDETO MATRICULATION," TEACH YOU. Send for FEEL BOOK SECRET Headphones, brand new, leading makes15/-, 23/. which explains the easiest and quickest and form for mild,. and super -sensitive30/-a pate,postageN. Single waytoMatriculate-FREEand Say Moderate, Elementary, or Beginner. Earpiece (new) 4,6 each, postage 64. withoutobligation. B.T.I.(Dept. SHIPS IN BOTTLES 160), 356, Oxford Street, London, W.1. MICROPHONES Mr. H. BECKER Just the thing for impromptu concerts, t0002 to mom communication. etc.Bakelite table model, " SCALEMOBILE " 619; Suspension type, 8/6.Post8d. Super Model Blue Prints for On. Scale Authentic ou' stand, 12/6. Fittinginstructionsincluded. Model Racing Cars.Engineers Job, Dept.9 5 8 ),69, Fleet Street, E.C.4, Mike buttons,2/6. Transformers, 6.6. Public Address Transverse current Mike,37/6,post 1/-. Not a Toy. 2 sheets, 22in. x 14in. Fully detailed and dimensioned. Chassis, ROOKS Al microphones have transformerincorporated. Axles. Body, etc. 16 E.R.A. British Sprint Champion. G.W.R. " Titans " or L.N.E.R., &R.... 1 6 MORSE KEYS AND BUZZERS AUSTIN o.h.v. Racing Seven. L.M.S. " Titans " ... 2 - Standard size keys wired to work Buzzer or Lamm GARDNER-MG 1946 Record Breaker L.N.E.R. " Renumbering " ... 2 6 Chromium plated,7/8, W.O.Key, heavy brass DELAGE and MERCEDES Grand Postage 2id.extra. bar, with en additional front bracket,9/6.Chromium Prix.5/- each, Packing ltd. Working Model Railways ... 2 6 plated, 1019, Post 04. No. 2 SingleCoilBurger,2/6. H. PRATLEY, 72, Waipolc Road, L.T. & S.R. Locomotives 4 6 No. Heavy Duty DoubleCoil,4/9, post3d. London, E.18. Loco Valves and Valve Gears ... 5 - The latest Constructional Ship Modern Loco Classes ... 8, - BELL TRANSFORMERS Postage 3d.extra. Kits British Loco Types (drawings).8.-. a 6 These guaranteed trans- ARMATURE RE -WINDING per post. formers work from any 00 0 A.C. Mains, giving 3,5 We re -wind all types of armatures and PARTS THE CUTTY SARK 5/6 or 8 volts output at 1 field coils, or if you wish to do your own Wagon Wheels (on one axle) ...9d.10d. amp., operate bulb, re -winding we supply a complete set of Coach Bogies, per pat8 318 6 Others available shortly hpaserorbell. Will materials for any specified job. New ballraces and commutators TYLDESLEY & HOLBROOK supply light in bedroom included if required. Ask your Dealer for these Kits or Larder, etc.PRICE Send particulars of your requirements 109, DEANSGATE, 7/-,Post 62. at once to JOHN F. KNELL, MANCHESTER,3. SOLDERING IRONS " Sherwood," Merry -End, Obtainablefromhigh-class AdjustableBit,allpartsreplaceable andfully Middleton -on -Sea. Sussex. reversible, A.C./ guaranteed.200,250 v., 60 watts,9!8: Diawatts, ELECTRIC motors, Model, Sports and Toy Stores 12/6,poet 6d. Small SolderingIrons,foruse D.C.,4/24v.(statecurrentsupply). on gas, 11.Post 4d. The last Word in Radio Kits." 10 ozs. 21in. x grin. x Olin.Designed for Twin tier, for lighting,64. ya;d.Power, 94. yard models. 25/S.-Emco, 118, Foleshill and postage. Toggle Switet is,son be used fel Really detailed Instructional Manu- Road, Coventry. Vacnutu Cleaners, radio sets, table standards, etc. script how to build best type of 4 valve 2/3.post ad. A.C..D.C. wireless,2:6(1. Absolutely NEW Machinery.-Electric Motors, COOPER -CRAFT LTD. SEND'Id. S.A.E. FOR ILLMERATED LIST B.F. complete Kit of Parts, including all Band Saws,DrillingMachine. Pumps, OF USEFUL ELECTRICAL ACCESSORIES. Mousy valves,speakerandsupercabinet, Grinders, Welders, em.-John P.Steel, WHOLESALE ONLY refunded if not completely satiellid .Letters only. £8 care. pd. Send postage (Dept. P.M.) Please include postage any excess will be refunded. for current Bargain List. Wholesale and Export Departments, Northern Radio Sem ices. 68. Park- NORWICH . ENGLAND hillRoad, London.N.W.3. Tel. ELECTRICMetalEngravingPens, HIGHSTONE UTILITIES, Gulliver 1453. runoil battery,10/6 post free.-Bulk, 58, New Wanstead,London,E.I I (P/M), 246, High Si.,Harlesdzn, N.W.I0. One of the following Courses taken at home in your "PRACTICAL ENGINEERING" said- spare time can definitely be the means ofsecuring We recommend all readers interested in improving their position substantial promotion in your present calling, or entry to apply for a copy of this valuable Book." Success in into a more congenial career with better prospects. Engineering " isnot a pamphlet. Itis a 132 -page book, ENGINEERING, AERO, ETC. containing valuable and vital information on all branches of engineering . .. There are many engaged in engineering who Plastics-Radio-AeroEngines-AircraftDesign- owe their success to The National Institute of Engineering. Welding-Aerodynamics-Electrical Engineering- The FREE GUIDE explains : Television-Electric Wiring-Talking Picture Work Openings, prospects, salaries, etc.,in Draughts- -Generation and Supply-Works Management- manship, Inspection, and opportunities in all other Metallurgy-Refrigeration-Planning, Estimating, Rate-fixing-Time and Motion Study-Aero Inspec- branches of Engineering and Building. tion-Automobile Engineering-Sheet-metal Work- How to obtain money -making technical qualifications Engineering Draughtsmanship-Aero Draughtsman- through special RAPID FULLY -GUARANTEED ship-Jig and Tool Draughtsmanship-Press Tool and COURSES. Die Draughtsmanship-Structural or RIF Concrete Write now for your 111/ Draughtsmanship-SanitaryEngineering. copy of thisremarkable GENERAL publication. Matriculation-CollegeofPreceptors-Chartered A.M.I.E.E., A.M.I.Mech.E., Institute of Secretaries-Aircraft Apprentice. A.M.Brit.I.R.E.,A.M.I.P.E., A.M.I.C.E., A.M.I.Struct.E., MUNICIPAL SERVICE A.M.I.A.E., A.F.R.Ae.S., A.M.I.S.E., M.R.San.l., School Attendance Officer-Handicraft Teacher- London B.Sc., Degrees. Registrar-Housing Manager-Sanitary Inspector- Fully guaranteed postal courses for Weights andMeasuresInspector-Inst.of Mun. alltheaboveandmanyother and Cy. Engineers-P.A.S.I. examinations. Fullydescribedin the Free Guide. THE BUILDING BOOM- SECURE YOUR SHARE! THE ACID TEST OF TUTORIAL EFFICIENCY The Free Guide also gives particulars of our SUCCESS -OR NO FEE extensive range of modern Building and Structural Courses, Building Draughtsmanship, etc.The great post-war Building programme offers un- We definitely guarantee that if you fail to pass the examination for limited prospects to technically trained men. which you are preparing under our guidance, or if you are not satisfied in every way with our tutorial service-then your. Tuition BECOME A DRAUGHTSMAN Fee will be returned in full and without question. This is surely QUALIFY AT HOME the acid test of tutorial efficiency. AND EARN BIG MONEY If you have ambition you must investigate the Tutorial Men and Youths urgently wanted for well paid and Employment services we are able to offer. Founded positions asDraughtsmen,Inspectors,etc., in 1885, our success record is unapproachable. in Aero, Jig and Tool, Press Tool, Electrical, Mechanical and other Branches of Engineering. Why not fill in and post the attached coupon NOW for further Practicalexperienceisunnecessary for those details and Free Authoritative Guide to openings in Engineering who arewillingto learn-our Guaranteed and Building ?This book contains a mine of valuable and exclusive " Home Study" courses will get you in.Those information and may well provetobetheturning point in alreadyengagedinthe your career. General Drawing Office should study some PROMPT TUTORIAL SERVICE GUARANTEED. specialisedBranchsuch as Jig and Tool or Press Tool Work and so con- ...... FREE COUPON siderablyincreasetheir scope and earning capacity. to NATIONAL INSTITUTE OF ENGINEERING (Dept. 29), 148, Holborn, London, E.C.1. Please forward your FREE Guide to NATIONAL INSTITUTE OF ENGINEERING NAME (Dept. 29) ADDRESS 148, HOLBORN, LONDON, E.C.I My general interest is in : (t) ENGINEERING (Placea cross against (2) AERO(3) RADIO(4) BUILDING the branches in which OVER SIXTY YEARS OF (5) MUNICIPAL WORK you areinterested.) CONTINUOUS SUCCESS The subject or examination in which I am especially interested is SOUTH AFRICAN BRANCH: P.O. E.C.S.A., BOX 8417JOHANNESBURG. To be filled in where you already have a special preference. FOUNDED I - FOREMOST TODAY -OVER I 0 0 , 0 0 0 SUCCESSES (rd. stamp only required if unsealed envelope used.)

Published about the 30th of each month by GEORGE NEWNES. LIMITED, Tower House. Southampton Street, Strand. London, W.C.2, "Practical Mechanics" Advice Bureau. COUPON and Printed In England by W. Speaight & Sons, Ltd.. Exmoor Street, London. W.10.Sole Agents for Australia and New Zealand -Gordon & Gotch (A ski), Ltd. Sole Agents for South Africa-Central News Agency, Ltd. Subscription Races (including postage): This coupon is available until March 31st, 1947, Inland, 10s. 6d. per annum.Abroad, 10s. per annum. Canada, 10s. per annum. Registered at the G.P.O. for transmission by and must be attached to all letters containing Canadian Magazine Post. queries,together with3 penny stamps. .1 CONDITIONS OF SALE AND SUPPLY :This periodical is sold subject to the following conditions. namely, that it shall not. stamped, addressed enrelope must also be enclosed. without the written consent of the publishers first given, be lent, re -sold, hired out or otherwise disposed of by way of Trade except at the full retail price of 9d.: and that it shall not be lent, re -sold, hired out or otherwise disposed of in amutilated con- Practical Mechanics. March, 1947 dition or in any unauthorised cover by way of Trade ; or affixed to or as part of any publication or advertising, literary or pictorial matter whatsoever.