JET OR REACTION PROPULSION Have YOU Joined the Well -paid Ranks of the TRAINED MEN?

MANY THOUSANDS MORE ARE URGENTLY NEEDED. PREPARE YOURSELF FOR A MASTERPIECES 10- BETTER POSITION AND BETTER PAY IN MINIATURE! Ambitious men everywhere have succeeded through Long experience and consummate skillin the art of model making has made the name I.C.S. Home Study Courses. So also can you. We Bassett-Lowke famousfordetailperfect offer you the benefit of our 53 years' matchless ex- scale models ofallkinds.To -day we are fully engaged on work for H.M. Government, perience asthe creative pioneers of but as soon as victory is won we shall be " Building a air,. postal instruction.Since our establish- gaugeFlyingScots- ready to resume production of Model Rail- man," fully illustrated ways, Ships and Engines for all our customers. ment in1891, more than1,000,000 with drawings and photographs, priceII - Our London and Manchester branches are British men and women have enrolled post free. still open and our wartime staff will be pleased Wartime stock list to give assistance on any model matters. for I.C.S. Courses. (L/12) price 4d. post free. The man with an I.C.S. Training in any one of the subjects listedbelow knowsitthoroughly,completely,practically. BASSETT-LOW K E9 Ltd. And heknows how to applyitinhis everydaywork. NORTHAMPTON Accountancy Draughtsmanship Motor Engineering LONDON :112, HighHolborn, W.C.I. Advertising Drawing Office Practice Motor Mechanic MANCHESTER :28, Corporation Street. Aeronautical Engineering Electrical Engineering Moulding Aaro Engine Fitting Engineer in Charge Pattern making Aero Fitting and Rigging Eng. Shop Practice Quantity Surveying Aeroplane Designing Fire Engineering Radio Engineering Air -Conditioning Fitting and Turning Radio Servicing S. TYZACK & SON LTD. Architecture Forgeman Refrigeration Architectural Drawing Foundry Work Salesmanship INCORPORATING GEO. ADAMS Boilermaking Garage Management Sanitary Engineering LONDON'S FINEST TOOL SHOPS" Book-keeping Gas -Power Engineering Secretarial Work Building Construction Ground Engineer Sheet -Metal Work ZITO" Building Contracting Heating and Ventilation Steam Engineering Business Training Hydraulic Engineering Structural Steelwork Super Quality Sliding Business Management Insurance Surveying Tallstoek Dieholder Cabinet Making Joinery Telegraph Engineering No. I M.T. shank, bongbarrel. Carpentry Journalism Telephone Engineering Precisionfinish. For13/161n. Chemical Engineering Machine Designing Tem plating O.D. dies.Price 9,6.For lin. Civil Engineering Machine -Tool Work Textile Designing O.D.dies.1211. With No.2 Clerk of Works Marine Engineering Textile Manufacturing M.T. shank,14,9. Colliery Overman Mechanical Drawing Toolmaking DELIVERY FROM STOCK Colliery Management Mechanical Engineering Turner Commercial Art Mine Electrician Welding We also stock Sell Releasing Concrete Engineering Mine Fireman Woodworking Die Holders. Willproduce Cost Accountancy Mine Surveying Works Engineering threads to correct length without Diesel Engineering Mining Engineering Works Management variation. Full details on request rid most ofthe Technical, Professional, andMatric Exams. Spec terms for members of H.M.Forces. 0 our advice on any matter concerning If you need technicaltraining, TILE "ZYTO" POUR WAY your work and yourcareer isyoursforthe asking-free and 'without Turret. Tooipost obligation.Let us send you full information regarding the subject in which you Spring locking action, hardened are specially interested.DON'T DELAY. Make "ACTION " your watchword. screws. malleable body. Base 41n.din.,height from base to The successful man DOES to -day what the failure toolrest 2ln., slze of turret 3in square.Price complete541/... INTENDS doing to -morrow.Write to us TO -DAY. DELIVERY EX STOCK

...-.Use this Coupon ... fie IN WO INTERNATIONAL CORRESPONDENCE SCHOOLS LTD. Dept. 95, International Buildings, Kingsway, London, W.C.2. ELECTRICGRINDERSAND (Use penny stamp on unsealed envelops) POLISHERS (Double -ended) Motors Please send me particulars of your coursesIn Complete with Wheels and Polishing Spindle. Full details on request DELIVERY FROM STOCK Name Age S. TYZACK & SON LTD., OK OM...... Iindress I CS 341-345, OLD STREET, LONDON, E.C.1 L ores Telephone: CLE -1004-5-6 April, 1944 NEWNES PRACTICAL MECHANICS 217

WARIIISERVICEfor owners of PHILIDME CYCLE DYNAMO LIGHTING SETS The great reliability, under all conditions, of Philidyne lighting sets has been proved by thousands of cyclists during the war.. On those rare occasions, however when a Philidyne set fails to function perfectly, our Service Departmentat WADDON FACTORYESTATE, WADDON, CROYDON, SURREY, is there to put it right. for light at walking speed

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24 218' NIWNES PRACTICALMECHANICS April, 1944 BOLT DOWN THAT MACHINE IN HALF. THE TIME with CINCH Bolt Anchors WO -R -S -E Suitable for all fixings to walls, ceilings and Boors of cement, brick, stone, etc. COMPLETE No delay :full load can be applied immediately. Depth of hole PRACTICE UNIT 40% to 60% less than ordin- as supplied to M.M. Services ary fixing methods. Cinch No. 1261. Complete MorsePracticeUnit. anchors give a quick and Heavy commercial Key with nickel silver con- tacts and sensitive triple adjustment.High -tone positive bite that holds per- Buzzer with silver contacts mounted on bakelfte base manently. Will not slacken or with cover.Battery Holder, complete with .'4.11- Ever Ready battery.All Metalpartsheavily nickelplated. work loose. Sizes to suit all and the whole mtd. on polished Mahogany Base, Olin. a 8? in. needs.IMMEDIATE DELIVERY. SendId. stamp for IllustratedList FAMPLEAND DETAILS ON RECEIPT 0; TRADE CARD. SIGNALLING EQUIPMENT LTD. (Dept. 19) HOYT METAL CO. OF GT. BRITAIN, Dept. P.M., Cedar Rd., Putney, London, S.W.15 Merit House, Southgate Road, Potters Bar. Phone : Potters Bar3133 POLARISEDDOUBLE-ACTING RELAYS ROTARY These are telephone -type Relays with polarised differential move- ment. Two 500 -ohm windings. QUICK MAKE & BREAK Large diametercontacts. k typicalexample offirst-.1,- BRITISH MADE THROUGHOUT workmanship. Asillost rat ,d. 17 6 Forallpurposes - fullytestedSwitches to ELECTRIC customers' requirements. MAGNETIC COUNTERS Let us use our long experience to solve your Switchini; problems. TOK SWITCHES LTD., CAMBRIDGE ROW, BURR AGE ROAD, WOOLWICH, S.E.18 550 ohms coil. Counting up to 9,999 Operating front 25 v. to 50 v. D.C. Many Sal and don e=rrapplications.(BIC, ell-O.P O., all pet fort.)8- I'. at LONDON CENTRAL RADIO Co., 23, Lisle St., London, W.C.1 SWITCHES

NORTHERN MODEL YOU CAN TIN ANYMETAL QUICKLY AND EASILY 35. Al RCRAFT COMPANY with FIRST PLACES 25,LOWER MOSLEY ST., AND HUNDREDS OF PASSES MANCHESTER, 2. Tel.:CEN. 1804 in theA.M.I.C.E., A.M.I.M.E., HOYT'STINNING COMPOUND A.F.R.Ae.S., A.M.I.Chem.E., C. &'G., etc., Exams,have been gained by students consisting of powdered metal combined with an active flux studyingathome withtheT.I.(1.11. Engineering First Placesare yourbest BLUE PRINTS NO SEPARATE APPLICATION OF FLUX, SOLDER OR TIN REQUIRED guide to ihe most successful Engineering JUST CLEAN THE JOB AND FOLLOW DIRECTIONS Courses. Write to -day for" The Engineer's SHIPS Guide to Success " containing the world's Heat the work and justsprinkle the powder evenly Engineeringwidest choice of King George V Class, upon surface to be tinned. The flux should " boil " Courses - over Nelson, 2181;., postfree. 200 - covering and its cleansing action will be assisted if the surface allbranches - M.T.B., 116. Ark Royal, 216. is scrubbed with a wire brush at this stage.Wheil Electrical,Mechanical, flux has all melted and the surface is tinned evenly Aeronaut Ical, Wireless.Civil all over, remove from heat and wipe with a clean rag. Chemical.etc. and which alone 00 GAUGE RAILWAY gives the Regu- Price per lb. nett carr. paid. lationsgovern- L.M.S. Standard 5 Plank Open Waggon. 6/3 ing admission to L.N.E.R. Standard I2 -ton Open Waggon. Dept. PM, DEODAR RD., PUTNEY, theRecognised L.M.S. Refrigerator Van. HOYT METAL CO. of GT. BRITAIN, Institutions.The L.M.S. Large Cattle Van. LONDON. S.W.15 World's best choice ofT.I.G.B. guaran- Wooden Contractors'HutorCoal Courses in Engineeringtees training Order Office. until successful Wooden Platelayers' Hut. The TECHNOLOGICAL INSTITUTE OF Coal Order Office in Modern Style. GREAT BRITAIN, L.M.S. 20 -ton Double Bolster Waggon. / /40 YEARS'reliable service to the industry 218, TempleBar House, E.C.4. All 9d. each Plus Postage. I WILL MAKE YOU A JUBILEE :01s1")1.1111 BRILLIANT PIANIST I do not say I may, but T say positively that I WILL if The long -life OLIVER PER CONTROL LTD. acceptyou an mypupil. I clip with the haveenrolled morethan CAMBRIDGE ROW, BURRAGE ROAD, 14.100adult pupils daring the ever -tight war, Miring 39 yearsI have WOOLWICH, LONDON, S.E.I8. taught over 83,000of all a;,00, grip occupations and degrees of TheBee: Known proticiency to play the piano brilliantly. I CAN TEACH YON. For evenIfto -day you do not know a Radiator Joints, note, to read and play at sight any standardIIIIISICalcomposition. I Air, Oil and Electrical and Mechanical grade Lessons personally to suit your ,Water Hose individual needs, using ordinary Joints Engineers musical notation, no freakish methods. MENU P.C. for free book and advice. we guarentte Bay Moderate,Elementary orBeginner Tight Joint MakersofVARLEYProducts Mr. H. BECKER L.ROBINSON & Co. Dept. 759). 25, Landes 69,Fleet Street, 11111111111111CAtiiGILLI ENT 41London. April, 1944 NEWNES PRACTICAL MECHANICS 219 War has beenplanned andrecorded in PYRUMA

The Myford Bench Motor Unit is suitableforuse with Myford 34" and 3A" bench Lathes, and is available in two types - MA.97 for flatbelt and MA.97A for vee-rope drive. Alevergivesquick adjustment of belt Tactics have been planned for the armed forces andcivil tension or immediate re- defence, from models made in Pyruma Putty Cement. History lease for changing speeds. of our armies in action has been recorded in national news- This machine is only one of papers by relief maps made in. Pyruma. Pyruma is the plastic theverycomprehensive cement that sets stone hard when baked or air dried,and rangeofaccessoriesand extra equipment available canbesizedand" coloured. IllustratedInstructi on sheet shows how to build models in Pyruma Putty Cement, obtain- to users of Myford able from local Ironmongers, Hardwaremen, Hobbies Shops products. and Bassett-Lowke Depots. Obtainable through your 2 lb. Tin 1/3 ;4 lb, Tin 2/3 ;7 lb. Tin 3(6. Tool Merchant. TILUMA in half -pound tin 1/9. Send for INSTRUCTION SHEET on modelling for Services, Educational and Utility Purposes. Est.1857. J.I.H. SANK.EY & SON,LI'? Ilford Essex MYFORD ENGINEERING CO., LTD., BEESTON, NOTTS. Head Office, Aidwych House, London, W.C.2 Telephone : BEESTON 54222 (3 lines)

CS" 78-37 Have you a Camera ? INSTRUCTION IN If so, read this. PLASTICS TECHNOLOGY Your photography will become much more interesting if you do it all yourself.To help you4,t we will send, for 3d. in stamps. these ANEW organisation has been formed tosupply ambitious people interestedinthePlastics three publications. A 32 -page booklet called Industrywithmoderninstruction in Plastics Home Photography, which tells you how, to Theory and Practice. develop your own negatives, how to make Gaslight and Bromideprints,how todo The new organisation, known as TheBritish Flashlight Photography and how to make Institute of Plastics Technology,is the specialist PlasticsDivisionofThe BritishInstituteof Azol,the Enlargements. A folder about Engineering Technology, Ltd., one of the largest concentratedone -solutiondeveloper,with home -study technical training organisations in the full Time and Temperature tables for tank world. There is also a fully or dish development. Specialist of Plastics Courses are being prepared illustratedlist and will be available within a reasonable period. useful Chemicals, Special Trial Offer: Thoseinterestedareadvised sundries and accessories to submit their For 2/3 P.O. Johnsons will names and addresses, when a copy of our Prospectus to help you in the work. send you post free(G.B. " OPPORTUNITIES only) a trial set of Chemicals, IN PLASTICS " will be includingx,oz.bottleof forwarded as our tutorial plans mature. Enrolment AZOL,todevelopeight for the special courses will first be offered to those spools zlin. by 3,tin., 4 -oz. tin ACID -FIXING, making whose names have been thus recorded, but no THESE THREE USEFUL 30-6oozs. solution,one obligation whatsoever will be incurred in lodging packet AMIDOL DEVEL- an application. PUBLICATIONS WILL BE OPER, enough for2to 3 doz.bromideorcontact SENT 'TO YOU FOR 3d. IN gaslight prints. BILITISII INSTITUTE OF STAMPS. PLASTICS TECHNOLOGY Be sure and mark your letter: Dept.41. 4, Shakespeare House, JOHNSON & SONS, Manufacturing Chemists Ltd., HENDON, N.W.4 17-18-19, Stratford Place, London, W.1 220 NEWNES PRACTICAL MECHANICS April, 1944

PREPARE FOR PEACE -TIME COMPETITION In the more competitive days of peace, technical training will be a vital necessity to the Engineer who wishes to safeguard his position and make advancement." ENGINEERING OPPORTUNITIES " will show you how to secure 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.I.Mech.E. Estimating A.M.I.E.E. Electricity Supply City & Guilds Electrical Meters City & Guilds . Foremanship General. Mechanical Eng. Jig & Tool Design General Electrical Eng, Electrical Design Diesel Engines Viewing & Inspection Alternating Currents Illumination Draughtsmanship & Tracing Welding Power House Design Installations Traction Telegraphy Works Management Metal Work --y, Press Tool Work Maintenance Eng. Mains Eng. Telephony Pattern Making Metallurgy Foundry Practice Refrigeration WIRELESS GROUP A.M.Brit.I.R.E. Advanced Wireless City & Guilds Radio Servicing COMMERCIAL ENGINEERING GROUP General Wireless Television A.M.I.P.E. Cost Accounts Short -Wave 'Wireless Talking -Picture Eng. Commercial Eng. Languages CIVIL ENGINEERING GROUP AUTOMOBILE ENGINEERING GROUP A.M.I.A.E. General Automobile Eng. A.M.I.C.E. Road Eng. M.I.M.T. Garage Management Inst. Mun. & Cy. Engineers Hydraulics City & Guilds Electrical Equipment A.M.I.Struct.E. Municipal Eng. I.A.E. Repair Certificates High Snead Diesels M.R.San.l. General Civil Eng. Sanitary Inspectors Structural Eng. Specifications Reinforced Concrete AERONAUTICAL ENGINEERING GROUP Structural Design Railway Eng. A.F.R.Ae.S. Aero Engines R.A.F. (Maths.) Navigators' Licences Pilots' Licences Aeroplane Design SURVEYING AND BUILDING GROUP Ground Licences Meteorology A.R.I.B.A. Costing & Valuations F.S.I. Heating & Ventilating UNIVERSITY DEGREES A.M.I.H. & V.E. Clerk of Works Surveying & Levelling London Matriculation University Entrance L.I.O.B. Intermediate B.Sc. F.A.I. Building (all branches) School Certificate WE DEFINITELY GUARANTEE " NO PASS -NO FEE" If you are earninglessthan £10a week you cannot afford to missreading" ENGINEERING OPPORTUNITIES " ;it tells you everything you want to know to make your peace -time 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-FREEand without obligation.

BRITISH INSTITUTE OF ENGINEERING TECHNOLOGY 410A, SHAKESPEARE HOUSE,17, STRATFORD PLACE, LONDON, W.1 THE B.I.E.T.IS THE. LEADINGINSTITUTE OFITS KIND IN THE WORLD April, 1944 NEWNES PRACTICAL MECHANICS 221

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Canada - - 10s. per annum. Editorial and Advertisement Office :" Practical Mechanics," George NeWnei, Ltd. Tower House, Southampton Street, Strand, W.C.2 'Phone : Temple Bar 4363 Telegrams :Newnes, Rand, London. at MECHANICS Registered the G.P.O. for transmission by Canadian Magazine Post. Owing to the paper shortage",TheCyclist," "Practical Motorist," and"Home Movies"are Copyrightin all drawings, photographs and articles temporarilyincorporated. 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 orimitations of any of these aretherefore expressly forbidden. VOL. XI. APRIL, 1944 No. 127

FAIR COMMENT BY THE EDITOR Electricity Supply and Distribution

FLECTRICITY supplyisaquestion to incur expenditure which does not promiseauthorities has increased and had reached interwoven with all post-war plans, immediate reward. 668 in 1930.The number is now approxi- and naturally there have been many During the war, network extensions and mately59o,the- reductionbeing due to schemesforitsreorganisation,andits the growth of domestic supplies have been amalgamation.The area covered by supply development.Most of these are concerneddrastically curtailed, but the vast- buildingpowers in 1921 was- just under I t per cent. with questions of ownership and control, but programme in prospect arising from wartimeof the total area of Great Britain, represent- there are many questions of a more technical arrears,the reconstruction and replanninging 73.6 percent.of the population.In and less controversial kind which will arriveof urban areas, and the urge towardsa 1935, 86 percent.of theareaof Great after the war. higher standard of living will result in rapidBritain was covered, and this area contained expansion of electricity supply and of the99 per cent. of the population.Obviously Standardisationis one of the most im- the areas with the highest population density itisimpossible to manufacture of appliances. portant, for without it The decisiontostandardise forfuturewere developed first.Of the 621 Supply simplify and standardiseelectricalequip- systems, voltages of 23o forlighting, andAuthoritiesinexistencein1936,53per ment. Many of the older electricity supply cent. together sold less than 3 per cent. of systems have not yet been standardised. 400 volts for 3 -phase power, was taken by The British Standards Institutionin1925, the total units, whilst 13 per cent. supplied Some operate on A.G., and some on D.C., and was generally accepted by the industry.approximately 72 percent.ofthetotal and thiscomplicatesthe manufacture ofShortly after this, in 1927, the Council ofunits.Undertakings vary considerably, not consuming devices, and considerably addstheInstitutiondecidedtoinvestigatetheonly in their outputs, but -also in size, some to the cost. As electricity supply is anproblem of securing the general adoption ofoperating anarea of afew square miles, essential public service it directly affects thethese voltages.They found that the cost ofwhilst othershaveareasof 4,000 square convenienceof consumerswhoto -day standardising voltages below 230 might range miles.The population density also varies. represent practically the whole community.from £ro,000,000 to £16,000,000, and aboveSome operateanarea withapopulation Wireless has made the public electricity23o between £r,000,000 and £1,5oo,000. density of130personspersquare mile, conscious.Before standardisation is possible Manyundertakings give supplies atwhilst others have areas in which the popu- technical developments must have reacheddifferent voltages in different parts of theirlation density is over 13,000 per square mile. a sufficiently high standard to permit it.. Inareas, and the capital expenditure on distri- A difficultywhichtendstoretard the electricity this stage was reached many yearsbution has been continually rising.In 1926development ofelectricitysupplyin rural ago, and accepted standards of voltage andit, was £117,000,000, and in 1.937 areas isthe cost of making connections to system are already in existence.So far as £294,000v000. isolated premises remote from transmission high -voltagesystems are concerned, these Substantial progresshasbeen made inworks. Theseconnections ofteninvolve standards are being generally observed. The recent years in changing overD.C.constructinglongspurlines,sometimes adoption of 4 -wire 3 -phase 400/23o volts systems to A.C., but in 1938 there were stillincluding transformer stations, in addition to at 5o cycles per second frecniency as the1,117,000 D.C. consumers in this country, low -voltageserviceworks. DifficultyhaS standardforlow -voltagedistributioninrepresenting 12 per cent. of the total.D.C. alsobeenexperiencedin obtaining way Great Britain is now generally accepted, andsystems are not only uneconomic, but cannotleaves for overhead lines and underground it is in the interests of the industry and thebe developed effectively to meet load densi-cables, and this has tended to retard develop- consumersifitsusecouldbe extendedties such as are now experienced. ment in urban and rural areas.Amenity throughout the country. Apreliminary non-standard ofA.G.objectionsare oftentroublesome, and are systems has disclosed, according to a report ofsometimes unduly stressed: The ElectricityCommissioners have the Institution of Electrical Engineers, that A further difficulty is the objection which recognised this and hoe taken steps to seemost of these undertakings provide 3 -phasemany owners and occupiers have to under- that wherever practicableitis adopted insupply for their large power consumers.Ittakings to make use of under -cave construc- new areas. The owners of many non-therefore has been recommended that thetion, that is, the attachment of cables under standard undertakings have already adoptedstandard of voltage and system on all low -the eaves of houses from acentral distri- it for extensions of their systems, but manyvoltagesystemsthroughoutthecountrybution point. The owner or occupier of of the older undertakings are still expandingshould be treated asa nationalindustrialpremises may demand a supply of electricity under the non-standard systems, and this is plansoastoevoke theenthusiasm andifthe premises are within 5o yards of a one oftheurgent problems which facegoodwill of the consumer, the undertaker,distribUtion line, but if the length of service electricitysupply' undertakings,foruntilandthemanufacturingindustryinco-linenecessaryto connect the premises is itissolved many oftheadvantages ofoperating to complete the plan in the mini-greater than 6oft., then the consumer may standardisation cannot be brought to fruition.mum possibletime.There would be nobe- required to pay the cost ofthe excess The difficultyisthat many of the non-technical difficulty in carrying out the work,length, and he may also be called upon to standard undertakings would be involved inand itcould be completed inaperiod ofpay for so much of the service line asis substantial costs in effecting the change -over.about five years. situated on private property. The cost of standardisation can usually be The firstElectricLighting Order was The wide variation in the cost of electrieiti justified on areasonable estimate ofitsissued in August, 1883, and this gave powerthroughout the country still remains a major future benefits to the undertaking, but therefor the supply of electricityin12 towns.problem, and itwill have to be solved in isoften reluctance in private undertakingsFrom thisdatethe number of statutorythe immediate post-war period. 222 NEWNES PRACTICAL MECHANICS April, 1944 The Development of Jet Propulsion A Brief Account of the Early Experiment- With Rocket and Jet-propelled Aircraft

- BRITAIN'S sudden leap into the lime- ByB.D. RICHARDSON through vents, and so obtain some help in light with the announcement that she is the steering and propulsion by reason of the "compressionreaction,""bottlepower," . leading the fieldin a remarkable race reactive force obtained. to discover new, more efficient and speedierwhat fits one, sitsfair and square on the With the discovery and focusing of interest Ways to hurtle through space fills us withother! on aerial navigation, and the first hankering aglowofpleasure. Greatcredit is towards controlled and powered flight, it is undoubtedly due to Group Captain WhittleEarly Pioneers only natural that this method of impulsion (the designer of the engine) and his staunch Let us trace within the limits of this short.should once again be explored, and so, about friendsfortheirperseveranceandfaitharticle as many of the steps as space willthe mid -nineteenth century, a minor crop of thiOugh long and trying years ;praise, too,permit that interweave the destiny of thisplans enjoyed a brief, mushroomlike exist- to W. G. Carter, who designed the 'planenew motivation.An acknowledgment mustence, only to disappear overnight with the aroundit --andnolittlecondemnation,bemadetoAlexandrineHero, whois advent of the spirit- and oil -driven motor. They ranged from suggestions to use power jets of steam forced through propeller blades to lift helicopters, to the grandiose scheme of the American Betty in 1860 to propel a semi -rigid gasbag by rocket force.There is on record a project of a M. De Louvrier in 1863 for an " aeroscaphe," vaguely described as " a kitelike machine driven by an airscrew or directly by an engine whose detonations cause reactions in the air."Later, in 1871, a design was put forward fora powder rocket-engined heavier-than-aircraft by a de la Pauze. Littlecanbetracedofanypractical application of these neoteric ideas until we gain the present century, unless we digress in an acknowledgment of the far-reaching development of the life-saving rockets used in shipwrecks.Then, early in the 5900's we hear of Parkinson patenting a turbo -powered airship of one man -power, the engine pro: viding pressure in the gasbags, with outlets from the sides of the envelope to be used for steering or propulsion, and of a model rocket 'plane being shown by an F. W. Fig. 1. i.-A historical flying machine, constructed about 1911 or 1912 by a Frenchman, M. Jourdan . Thomas at the Alexandra Palace Exhibition credited with the invention in 150 B.C. oforganised by the Daily Mail in 1907.With perhaps, on the aviation industry as a whole the opening of the century we discover first - on their somewhat tardy recognition of the asteam -jetapparatus, whichutilisedthe consequent reaction of an escape valve to:class scientific brains directing their energies implications and significance of their struggle. towards harnessing reactive expulsive force. With newspaper and radio blaringrevolve a sphere ; though there is no evidence uumpetings, the public are at one and thethat this" " was ever constructed. The names of the Russian Ziolkowsky and same time getting both the truth in the formFor our purposes, the experiments directedthe Rumanian Oberth leap to the memory towards harnessing the reactionary force ofasassociatedwith the researchintothe of an actual fait accompli and an erroneous properties of liquid fuel as a propellent, and impression thatitisaprinciple we have therocket commenced withasuggestion discovered.It is the latter that this articleproposed by an Italian, Fontana, about 152o,the hunt was on.A bewildering galaxy of is designed to correct. The jet -driven enginethat it could be used to propel a vehicle, andnames representing a variety of countries can is only yet another application of the olda similar theory propounded some 200 yearsbe presented now as typifying the scientific principleknowntomanystudentoflater by the Dutchman Gravesande, to useinterest that has been brought to bear on the sciences,otherthanaerodynamics,thatpower jets of steam towards the same end.absorbing problem.Itis not the purpose forward progress can be obtained by kickingLater, in 1784, two Frenchmen, Janinet andof this article to give a categorical and full sufficiently hard against something in yourMiolan,are reputed to have projected a hot- listof these pioneers, but, having roused rear equally as well as by the more acceptedair balloon which was to directits excessinterest, a slight acknowledgment and tribute Method of chewing off large chunks of what- ever lies in front by the use of a propeller (whether tractor or pusher) and heaving the body forward by these teeth. Even the least scientifically minded of us must admit the wonder with which we regarded the little toy the Christmas hawkers at the kerbside familiarised us with for so many years ;I refer to the miniature shirt (or duck), consisting of a mere outline on a light fiat base, the rear of which supported asmallpieceofsodium(orsometimes " Meta " fuel) whose emanations in the water drove the little craft forward in a seemingly amazing manner. This new engine is indeed a marvellous invention, and its advent entirely eclipses for at leastadecade the approach made in the last eighty years to arrive at a similar satisfactorystagefromquiteadifferent angle ;Irefer to the attempts to achieve rocket flight.I think that we cannot fail to recognise thatflightattained by these means has as valid a -claim to the title of jet -propulsion as its more recent rival.In fact, we can call the principle what we will, Fig. 2.-A later version of M. jourdan's machine. April, 1944 NEWNES PRACTICAL MECHANICS 223 to the following men will prove useful tofrowned upon and rendered almost unattain-to hand as to whether they actually flew, and those who wishtopursuetheirstudiesable on the plea that we were such a smallwith whatresults. Theaircraftjournal further. GermanycontributedDrs. J. country it was unreasonable to find a placeFlight, as fat back as 1932, was quick to Winkler and V. Mandl, Willy Ley, F. Opelwhere theycouldbeconductedwithoutpoint outthekigical sequencethatcon- and Max Valier, R. Tiling and G. Zuckerdanger tolivesand property(except,ofnectedthisrevolutionaryideawiththe (thelattertwo mentionedbeing powdercourse, on Government firingranges,in appearance in that year of the Stipa-Caproni enthusiasts as opposed to the more acceptedwhich case there was little likelihood of a(Fig.3), 'the result of five yearS pursuit of liquid fuel).The United States of Americacivilian obtaining permission to make use oftheproblem. Thisall -wood,mid -wing produced Drs. Greely, Abbot, A. C. Ericksonthem forallthe long preliminary experi-monoplane embodied an identical principle, and D. Lyon, Prof.R. H. Goddard andmental work that would necessarily precedebut provision was made forthepilot to D. Lasser.France:Dr. Robert Esnault-an official test). straddlejockeywise the tube in an open, Pelterie, Andre Hirsch and M. Konstantinoff. Italy: L. Gussalli.Austria: Dr. E. Sanger and F. Schmiedly (another powder enthu- siast). Czechoslovakia :Ludvik Ocenasck. Holland : Roberti in association with Thollen ; and Russia has given us in addi- tion to K. E. Ziolkowsky (already mentioned) the name of Dr. Nikolai A. Rynim.In this country, too, we have had contributions from the well-known Prof. A. Low and P.E. Cleator.Necessarily a veil has been drawn across the progress of their work of recent years, but we can all remember their contri- butions prior to the war. Rocket Flight The first man -carrying rocketflightis credited to F. Stahmer in1928, and the second to F. von Opel in 1929 (Fig. 5), both taking place in Germany.Itcannot be claimed that they were successful expositions of. controlled powered flight-one is left with the impression that it was the rockets that took control and that these early pioneers were fortunate toescape with theirlives. Theseflightswerecloselyfollowedby Fig. 3.-The Stipa-Caproni monoplane. another essay, this time on the part of anotherHistoric Machines compactfuselagesection,andthetube Gernian, Espenlaub, in a rocket -firing 'plane Let us now leave the story of machines extended the complete length of thecraft designed by Max Valier ; but again there isfired by rockets at this inconclusive stage,to the rear, where it encased most of the nothing conclusive to record.In 1934 W. G.and exanline one more facet.I refer to the tailunit,obviously with the intention of Swan puformedsimilarservicein Newtype of machine which intrinsically in itselfgettingthe greatest benefit from the slip- York. constitutesonehugerocket(orpower stream.The 120 h.p. engine was mounted Most rocket experiments since then havecontainer).To do this we must cross overjust insidetheleading edge ofthe tube, been of a less practicableto the enemies' camp, asit were, and forwith the propeller tips barely clearing, and nature, and generally have taken the formthe sake of history show by what steps jet- when the machine was flown it was reported of sizable craft for mail -carrying purposes.propelled flight has been evolved from itsthat she pOssesSed exceptional stability, less Ifitwould appear that this country lagsmore conventional brother. Fig.Ishows head resistance, increased rudder and ele- behind, it is only fair to our potential inven- a historicalflyingmachineconstructed vator efficiency, plus better visibility for the torstopoint outthattheyareseverelyabout 1911 or 1912 by a Frenchman, M. pilot.The wings were wire braced, and it handicapped by the dictatorial attitude of theJourdan, who pursued a theory of obtain-would be interesting to get details as to their HomeOffice,which,even inpeacetime,ing additionallift by capturing the entire behaviour. actively discouragesprivateexperimenters.slipstream in a partly enclosed fuselage ; and The advent of this machine was closely Thispositionisindirectcontrastto Fig. 2, a later version of the same machinefollowed with a report from New York that Germany, who encouraged and fostered the withimprovements, consistingofa com- anInstituteinCalifornia was examining development of this form of research, andpletelyenclosedtubefuselage,withthe a design of a General Rocco, of the Italian as early as 1930 placed a specially establishedpropeller also encased.In both these mach-Air Ministry (though why he had to cross experimental flying field at their disposal on inesthe engine andpilotshared in the theAtlanticforthisconcessiondid not the outskirts of Berlin, complete with hangarsbenefits of the whirlwind thus raised, and it come to light).This was no less than :" a and workshops. Over here experiments wereis unfortunate that the author has no data superplane "tospeed through the strato-'

Air Compressors & Heaters

Air issuing Air enters here Exhaust Gases from Tai!et !'Motor- driven ejected through supplies Air Compressors Duct motive force

Fig. 4.-The Caproni-Campini C.C.2 let -propelled aeroplane (1941). 224 NEWNES PRACTICAL MECHANICS April, 1944 a hollowed air duct, whose function isto scoop, the air and force it through a battery ofcompressors,driven byanespecially designed engine, which also undertakes the taskof heatingit. The hotairis then forced into an ever -narrowing tube, emerging through asplayingnozzle which projects from beneath the tail unit. The scanty reports reaching this country were chisely shadowed by talkof similar experiments on the same lines by the Arado concern in Germany, and hints regarding thetrialsandsetbacks oftheinternal- combustion turbine sponsored by the Swiss Company of Brown Boveri ; and now comes theofficialcurtain -lifting thatBritain has entered the lists with a dark horse that has been long and careful in the fashioning. We learnthat Group Captain Frank Whittle's experiments started as far back as 1926, and that they entered the final phase in 1933. culminating in patents being taken out in 1936-withthe resultthatthe prototype first took the air in May, 1941. 5.-The Opel rocket -propelled aircraft (1929). Glider Bomb It may well be that the Arado concern sphereat more thanr,000 m.p.h.Thison December 1st,1941.As will be seenhave developed a rocket -'plane suchasis modest achievement was be accomplished by from Fig4,she was a low -wing mono -,'envisaged earlier in this article, and that it arocket-like 'plane,propelled by burningplane, with the appearance of a thin, stubby isastable companion to the rocket gun, petrolinlong,open-endedtubes,thecigar.The wings, of very small area, wereabout which we have heard so much recently. power forthis purpose to be supplied byfinely tapered, and the crew of two occupiedIndeed, some such developmentisfore- three Rocco -designed tube engines, whilsta well -designed cabin in the now accepted shadowedbythescantyPressaccounts anordinaryinternal - combustionengineposition astride the tube.The nose, per-recently released regarding the German use would be used for the initial take -off and haps, would be thefirst pointtoattractof a.- newjetorrocket -propelledhigh preliminary climb to some 15 to 25 miles.attention by reason of the absence of pro-explosive glider bomb sometimes quoted as However eulogistic the claims and expecta-peller, and its curiously flattened silhouette.Henschel Hs.293, controlled by radio from tions may now appear at this distance inAn unusual excrescence beneath the fuselage aparentaircraft(identifiedas -Dornier time, itis apparent that modesty was givenaft betrayed the presence of the unorthodox 217). The bomb isfitted with wings of her fair share in the bombast when it was characteristicof afairingconcealing thesmall span and atailunit.Itprobably suggested, in such amatterof fact way,`expansion chamber.The Press of that yearaverages about 26o m.p.h., and its weight that to attain the initial height quoted, beforereported herflight from Milanto Romewould be about r,000 to 2,5oolb., and it is the new Rocco tubes were brought into(including a stop at Pisa), a journey of somecarried slung beneath theaircraft, which, play, an " ordinary " engine would be used.170 miles, which was accomplished in aboutflying on a parallel course to its target, and This announcement was followed by a lopg21 hours, at an average speed of 13o m.p.h.out of reach of its A.A. guns, releases it, gasp, and an equally long gap ;althoughOther accountsstate that the13o m.p.h.and by remote radio control steers it to its there was also a turbine-engined aeroplanequoted was, however, not the average, butobjective. exhibited at the Paris Aero Salon of 1911,represented the maximum.Itis computed It isalways unwise to attempt to pro- designed by Henry Coanda. thather loaded weight would beof thephesy, but if one may hazard a guess as to order ofr,000lb.Her unconventional dis-the track of these parallel lines of develop- The Caproni-Campini ' When the war is over we may hear ofappearance of propeller and engine mountingment and essay to envisage the place where, intermediate machines, but at the time of isfurther enhanced by the absence of thein sucha future that Einstein postulates, going to press, the next step in our chainrhythmic beat and droneofthe normalthey converge, I would suggest that itis the engine,itsplace being taken bya loudfeasible that in both cases the tendency will appears to be from the same stable : humming.Itisclear that the hummingbe for the old established tail unit to disap- Caproni-Campini, the `C.C.'. of1939/40, pear (like that of the tadpole), its functions believed to betheresult ofthe patientpersisted long after the flight was completed research work of the same L: Stipa of the-it echoed through the corridors of everybeing taken over by a multiplicity of jets Italian Air Ministry, who was responsibleAir Ministry and 'plane factory in the wholespread over the entire span of the" 1932, alreadyworld.The industry seethed with excite-wing " (or finally wingless) craft.This stage forthe Caproni product of ment.Here was an entirely new type ofmay be reached by a natural evolution that referredto. One day we Jhall probablyengine constructed to harness the air andpermits of a retracting wing (Fig. 6) in the hear more of the story of this revolutionaryuse it far less wastefully than any other typeintermediate years, pendingthe fuller craft,butallthatcan be gleaned fromof power unit of a similar weight. There is nodevelopment of the rocket discharge type of contemporarysourcesisthatshe wasa single -seat monoplane, and rightlyfills theengine housed in the nose, instead there iscraft. transitional stage between the original Stipa- Caproni, which was purely atractorair - screwed machine, in a novel frame, and the complete breakaway of the Second experi- mental machine, the C.C.2, which dispensed entirelywiththehithertoaccepted -as - necessaryairpropeller. The C.C.Iwill stand forall time as theinitialstep, and should be enshrined in the annals of science alongwithStephenson's" Rocket "and Montgolfier's firstballoon. Her designers had not atthis early stage overcome the difficulties of the take -off, and so relied upon the normal tractorscrewtogive her an assisted passage in this respea, and once an adequateairflow was established,thejet - propulsive mechanism was brought into play andthepropellerdispensedwith. The first attestedflight was apparently under- taken in August, 1940, and it would seem that already by then the idea of suitable induction machinery had been satisfactorily worked out for her successor, the Caprom- Campini C.C.2. The C.C.2 must have been on the boards at this time, as she made her maidenflight Fig. 6.-An impression of a wingless jet-propelled aircraft of the future. April, 1944 NEWNES PRACTICAL MECHANICS 225 A Water -drivenCharging Plant Constructional Details of an inexpensive Unit Chain Drive to Countershoft ByF.G.and H.J.RAYER Piles driven Into Bed of Stream

IF asuitablelocation can be usedfor SupportingBrackets buildingacharging -plantdrivenby water power itwill be found thatit has many ad ,,antages over the more usual wind-drinn unit. A windmill runs at vary- Wooden ing speeds, depending upon the velocity of Platform thewind,andifanefficientvoltage - regulator is not used there is the danger of charging the batteriesata ratein excess of that which should be employed when Belt Drive the weather is gusty, while in calm weather the unit will not work at all.None of these disadvantages are present in a water -driven Dynomo plant, for the dynamo will run at constant speed, and itwill be possible totrickle- ,. charge a small cell at a constant .1 amp., or charge a large accumulator at 6 amps., as desired. The charging plant here described (Figs. s and 2) is not difficult to build and will provide sufficient current to charge 52 2 -volt accumulators of normal capacity simultane- ously. The dimensionsgivencouldbe varied and a smaller or larger unit built, if desired. Additional LayerofBricks Flow Sliding Board to control Cemented to Waterfall The Water -wheel Flowof wow This is not so complicated as might at Fig.r. Plan of the completewater -driven charging plant. first sight appear.Itis quite small, being only 2ft. in diameter by 2ft. wide. Dynamo and Gearing It is made entirely of wood, eight Cut-out .As the water -wheel is of small pieces of board 6in. by 2ft. being diameter it will turn rapidly, and used for the centre, and 16 pieces To Pnomeworm in the original model built it was 01 Cot -out 412in.by2ft.forthebuckets. Ammeter foundthatastep-upratioof Fig. 3 shows the shape and method : 20 was ample. The drive of construction. The wheelis fromthewater -wheelto the fittedwithanironaxlewhich countershaft is a bicycle chain, the passesthroughtwoironcross- " crank " gear being fitted to the pieces nailed to the wooden ends lower shaft, which is filed to the of the wheel.When the wheel is correct size to make a proper fit. completeditshould be given a A leatherbeltisused between thorough coating with some water - countershaft and dynamo, and the F roBotteries resistingpaint. The method of0 illustrations make clear the methcid arranging the bearings of the wheel of fittingthis. The dynamo is is shown in Figs. i and 2 ;all the clamped to a 2in. wide and tin. necessarymetal'partscanbe thick strip of iron which is screwed obtainedfrom ablacksmithor Fig.4. --Diagramofelectricalconnections. tothe one countershaftbearing ironmonger's for a few shillings. support and to the wooden plat- Ornama form ; by loosening the clamping screws the dynamo can be moved along the strip to adjust the belt to the correct tension.The whole assembly should run truly and easily, and the bearing should be kept well greased. Boardto guide flow Construction of Framework Timber 3in. by Sin.is used throughout, theseparate piecesbeing bolted together Water Level by lin. diameter bolts of appropriate length. All the woodwork should be painted or creosoted,especialcarebeingtakento thoroughly treat those parts which will be immersed in water.Although not shown in the illustrations for the sake of clarity, a - hut -shaped box should be built to fit over -7- - the platform to protect the dynamo, belt, Waterwheel " - =- - etc., from rain.The countershaft passes through a hole in one side, and the cover should be fitted with a hinged lid, so that access may be had to the charging -board I- p *:.

" andbatteries. Itcanbe coveredwith

. roofing -felt to make it watertight. Water Level

I Electrical Details The dynamo, cut-out and ammeter were obtained from a garage. The dynamo is of the Piles driven in o Bed of Strewn 52 -Volt 8 -amp. type, although a 6 -volt unit Fig. 2.-Side view of the plant, showing the construction of the framework. could be used if desired. If the dynamo used 226 NEWNES PRACTICAL MECHANICS April, 1944 cross -piece mode 0, ek,- rimbv is fitted with a separate field -connection this should be connected to the plus terminal of the 'dynamo, so that the maximum charging rate is obtained.Some dynamos are fitted with a movable brush to adjust the current output ;ifthisisso, the brush should be moved as far as possible in the direction of rotation ofthe dynamo. The cut-out guards against any possibility of the batteries run- ning down throughthedynamo. The ammeter obtained had a rnaximutn reading of 16 amps., which was too great for the purpose. Theinstrument,whichwas obtained from a garage; was opened, and the operatingcoil,which consisted of 21 turns of wire, was replaced by a coil having 5 turns, so that all the readings were halved. Itis not proposed to give details of the charging of batteries, as a series of articles have lately appeared in Practical Wireless dealing with this matter fully (P.W . Novem- ber and December,1943). The required charging-turrent for the batteriesin hand is obtained by adjusting the flow- of water on to the water -wheel, this being done by raising or lowering the sliding board in the chute which carries the water to the wheel. The board is fixed in the required position by means of a small peg.It was found of Wore'- buckets mode Boards nailedtocross-oioe advantage to fix a piece of small mesh wire ety:fsof Wotor7buckets netting in the stream immediately above the f.rom Boards on d water -wheel, so that drift* pieces of wood, and leaves,etc.,could not block up the water -chute, and partially stop the flow of Fig. 3. ---The water -wheel, withone side removed to showthe shape and construction of the water. water -buckets. "Tank Bustin Various Weapons forEffectivelyDealing With Enemy Tanks. By R.H. WARRING PARALLEL with the development of anytypes without exception,it. was impossiblefighters were being armed with cannon, and weapon of warfare is the- developmenttosee any object immediately above thefrom thence onwardsit was regarded as of methods to nullify or destroy thattank or on the ground within a radius ofstandard.The R.A.F. cannon is a British weapon. Inthemain" defence "lags about twenty feet of the tank itself.TheHispano, with zo mm. calibre, each shell behindoffence, anentirely new offensiveonly solution to this problem was to openweighs one quarter ofa pound.Aircraft instrument having in the initial stages thethe lid, when the observer is exposed to anysuch as the Beaufighter, Hurricane B, advantage of surprise.But tanks are notdefensive fire. Mosquito, etc., carry four cannon, with a new and neither are the methods devised In formation tanks are able to cover onetotal rateoffireof 2,400 projectiles per for their destruction.Both, however, haveanother's blind spots, and therefore are muchminute or a total weight of fire of 600lb. made extremely rapid progresssincethemore dangerous than when isolated.Again,per minute.These are now followed by the beginningofthiswar,andbothrankthe majority of tanks are unable to depressHurricane II D, with the 4o mm. cannon. amongst the major factors of any land battle.their guns to fire at anything at ground level The smaller cannon shells proved them- Tanks, well directed and supported by thewithin a radius of 20 feet or to fire upwardsselves capable of penetrating light armour, ancillary services, can establish a superiorityabove an elevation of 25-3o degrees.Turretand also did quite an appreciable amount on any battlefield out of all proportion- ofguns must be revolved, and this takes time,of damage if mixed up with the tracks of their true value unless met by well -plannedso that a rapid change of direction of heavyenemy tanks.But they were not always anddetermineddefences. Theirmostfireis not possible.Hence the advantage effective ;fired at an angle, they ricochetted spectacularresultshavebeenachievedof simultaneous attack from different off the tanks or failed to penetlate thicker against ill -formed, badly. equipped and half-directions upon an isolated tank. armour. hearted troops ; their most disastrous against some point at which adequate defences haveUse of Aircraft Dive -bombers been concentrated. Aircraft, in particular, are suited in this The Russians tried another scheme-using mannertotankbusting,beingquicklywhat was virtually a dive -bomber fitted with Immobility capable of changing direction or evading fire aparticularlyingenious bomb.To this In spite of their mobility, armour, oftenput up by the tanks themselves.Groundbomb were attached rocket jets, and, when heavy armament and terrifying effect, tanksforces or covering air forces are requiredreleased, it did not drop in the usual manner, possessmanyweaknesses. Possiblytheto protect the tanks from such an attack. but was hurled forwards by the rockets, greatestoftheseisimmobility, resulting However, a tank has comparatively fewskidding along the ground until reaching a from damaged or displaced tracks.A tankvulnerablepointsagainstordinarysmall - substantial object. The " substantial object " is only mobile as long as these tracks holdarms fire.The observation slits are oftenwas, of course, intended to be the tank, and out.Broken or removed by any means, itprotectedbybullet-proofglass, butthiswhen such a hit was registered the tank may become ametal stationary armoured" glass " stars, obscuring vision, and has tocould be considered as so much scrap metal. pill-box' but is subject to any concentrationbe replaced when hit.Such slits are given BeaufightersandHurricanes have had of the defensive fire.A disabled tank isoverhead protection by means of a smalltheir share of tank -busting in the Middle capable of being a great nuisance, but" it metalplate, and thusitisrarelylikelyEast, and itis interesting to speculate on must remain stationary until repaired, andthat machine-gun bullets from an attackingthe latest of the Hurricane family-colloqui- thus loses the majority of its usefulness. aeroplane can ever hope to penetrate.Forallynamedthe" Hurri-buster " - which A disabled tankisfurther handicappedthis reason tank -busting aircraftis drawnmounts two large calibre cannon, one under onaccount ofits relativeblindness.from those types fitted with cannon. each wing outside the air -screw disc, firing Obviously all openings must be reduced to Cannon projectiles of sufficient size to penetrate all a minimum if the armour is to be effective, but the toughest armament.It is interesting and so the only view availableis through Although we were somewhat backward into recall that so long ago as 1917 a F.E. theinspectionslitsused bythedriver,adopting cannon as armament for aircraft,2.B machine was in service with No. 213 commander, gunners and periscope, if fitted.theUnder -SecretaryofStateforAir SquadronfittedwithaI -poundergun, On many tanks, and almost all the earlyannouncedinMarch,1940,thatBritishwhilstin1933Blackburn" Perths "of April, 1944 NEWNES PRACTICAL MECHANICS 227

No.209FlyingBoatSquadronsportedpiercing projectile,iseffective against lightis more likely to be seen in local invasion 37 mm. Vickers cannon firing tA shells.atipte at relatively short range, and againstareas. Rate of fire was about too "brojectiles pertrckj of all types of tank.It suffers from The art of stopping tanks, although more minute. Even bigger amounts weretie same defect as all small weapons in thatinthe nature of " passive "defence,has experimentally mounted on isolatedprojectiles may " glance off " armour fromalso produced its surprises and developments. machines. any but a near perpendicular hit. In the first place a most formidable road One anti-tank measure, which has beenis useless if the tank may circumnavigate it, Recoil siptiLarlyemployedagainstalltypesofandlayingminesaroundthispossible The main problem connected' with such ground forces, is the land -mine.These areinvasion path is not always practicable. relatively large cannon fittedtoaircraftisgenerallyarrangedinspeciallyprepared recoil.Some oftheearliestexperimentspositions, having entrance to any specificTank Traps resulted in the machine in question stallingregion (synonymbus with sea -mines) or sown Defences may also have pits dug as tank - each time the gun was fired, so great ;Valindiscriminatelyasaretardingmeasuretraps, though these have often proved more the recoil.Then some ingenious engineerduring retreat, to hampe,r the enemy forces effectiveas" reservoirs " of muddy s water hit upon the bright idea of simultaneously following.Many specialised forms of anti-than their original object.Such a pit must firing a blankchargeintheoppositetankminesareemployed,capable ofbe at best one half the length of the largest direction to that of the shell.This was tried:immobilising the majority of tanks in use.tank itis intended to stop, and even then, out-but the resulting explosion nearly blewThey are also effective in blowing off theirif approached at speed, the tank may jump the fuselage in halves No doubt, however,tracks. such a distance.Raising the other bank so a satisfactory solution has been reached in that a jump is impossible may be all right- the case of the " Hurri-buster," or posSiblyMolotov Cocktails unless the tank approaches from the other the cannon are not as troublesome as first For individualisticeffortthe destructiondirection, when the bank will help it. suspected. oftanksatclosequarterspresentsa The most effective counter-measure is the hazardous and courageous 'job.The well-anti-tank mine, sown intelligently and well Weak Points known Molotov Cocktail of Home Guardconcealed, while decoys and booby traps may Further points of vulnerability of tanksfame consistsessentially of a glass bottlebe linked with their use.A harmless layer (the slits being most open to small -arms firecontaining a mixture of petrol and otherof straw or a sheet of canvas laid on a road close in) are the belly-generally the spotinflammable substances, such as tar, dieselmay, at least once, cause a tank commander wherethearmouristhinnest-thetop oil,etc., so that the solution sticks to theto suspectconcealedminesorother surfaces, again armour thinner than sides ;surface of the tank when. the bomb has beenobstructions and make a detour. the louvres and vents, and the turret. thrown against it and burst.Some simple A tank cannot climb a defile which results

A ground crew servicing a Hurricane " Tank Buster."The 40 mm. cannon can be seen housed under each wing.

To direct against these points the defend-form of ignition is fitted, so that when thein itsaxis jaeing tilted beyond 4o degrees ing forces may have a large assortment ofbottle breaks the mixture is fired. above the horizontal, neither can it climb weapons, from riflefire to liame-throwers. Fromthisrather" HeathRobinson " avertical face which ishigher than the Rifle fire, as explained above, is only effec-contraption the next step is the phosphorustop of its tracks.Thus many natural tank tive if directed against openings in the maingrenade, again a glass case with a mixtureobstacles may be found and, where not quite body of the armour or against an observerof phosphorus and benzine, which will ignitesufficient, may be supplemented by artificial stationed in the open lid of a tank.Thespontaneously when the bomb bursts (i.e.,means. latter generally adopts thisposition whenthe glassisbroken by impact). Besides Trees and tree stumps likewise often prove running over relatively " free 'ground, andproducing extremeheatinburning,thegood " traps,". but unlessthetrunksare so is thus susceptible to surprise attack, butphosphorus grenadealsogivesofflargegreater than t8in. diameter, single trees will in action the lid is closed. quantitiesofdensewhitesmoke, whichbe crushed and broken by a medium tank. makes the interior of the tank particularlySmall trees become more effective if possess- Anti-tank Guns unpleasant. ing depth, such asinacopse or wood, One of the main defensive weapons is the The next step was the" sticky -bomb,"Particularly if closely placed.Tree stumps' anti-tankgun. This has advanced fromso called becauseitsticksto the sideofof about 3ft. in height and 2 or more feet being an ordinary field -gun firing practicallythe tank when thrown against it and thenin diameter are often effective in lifting the horizontally into a specialised instrument. Abursts.The high explosive contents (nitro-belly of the tank and thus raising the tracks detailed description of such types, even ifglycerineorsimilar) was detonated by aoff the ground, but a single line of stumps this were permitted, would occupy a wholefive -second fuse similar to that of a Millsit ineffective, i.e., a " depth " of defences is volume. -By -themselvesand/orartillery,bomb. required. provided they are not " saturated " by the But the majority of tank battles at the Once immobilised, the tank may be dealt attack, they are the most effective means ofpresent time have generally ended in a duelwith inthe manner describedaboveor, defence. between tank and tank, or tank and anti-turned from its course, may be forced on The anti-tankrifle,firingan armour-.tank gun rather than individual effort, whichto ground more favourable for the defences. 228 NEWNES PRACTICAL MECHANICS April, 1944 Small Wincl-power Plants --4

Erecting the Pole : Instrument Pane! and Wiring By W. H. SUTHERLAND (Continued from page 187, March issue.) THE successofa home-made wind - climbing steps are made from lengths of solid r/roin. copper strip, which, along With that charger depends to a large extent on fin. iron bars, driven into Bin. holes in the already taken from the coils of the A 90o C, the erection, wiring, and associated new timber. Four inches will be found reached to the panel. To join the strips, clean equipment.Usually a wooden pole is the sufficient to leave projecting.Such(' a system If in. of each with emery paper, bind together only type available.One sees very manyof stepsis much easierto climb than a With bare 18 or 20 gauge Wire and melt solder small units perched on top of light poles well into the joint.Alternately drill small only 3m. or 4in. thick, but sooner or later 6 B.A. holes and rivet the strips together they disappear from view.It is very easy with brass boot nails before soldering.The to underestimate the power of a storm, bur conductors are held on the pole by wooden it is a mistake that is seldom made a second blocks every 36ft., some of which can be time. A small pole must be well tied with seen in the photograph. No attempt is made guy -wires, particularly in the direction of to cover the wire, either here or any other the prevailing wind.It is much less trouble point in the lighting circuit, since no leakage in the end to use a large pole containing occursat6 or12 volts across timber or the greater part of a good straight larch or plaster.The problem of raising the heavy fir tree, sunk about 4ft. in a hole filled with pole, with the weight of the windcharger loose stones and cement. Once erected, already assembled on top,isbestsolved such apole formsa permanent support individually.Ten men were needed to lift worthy of the best windcharger. into position the pole illustrated.A home- made windcharger should always be " run- in"forseveralweeks onasmall8ft. Erecting the Pole temporary pole, where weak points in the It is usually convenient to erect the pole construction can be detected and corrected. beside the wall of a house, to which itis secured by two iron bands, passing around InstrumentPanel the pole, anti through a hole in the wall. An ammeter andacut-out formthe The pole in the illustration is held in this essentialpartson the instrumentpanel. wayatapointabout13ft.fromthe However, we shall describe the construction ground, the total length above ground being of an elaborate panel, and each reader may 32ft. The bands used were two leaves include as many of the refinements as he from a motor -car spring, bent to "embrace " likes.The operation and wiring of a cut- the pole, where they are held in position by out often puzzle beginnerg':Two separate abolt, and boltedsimilarly overa long coils are wound on the electro-magnet,- a flatiron platebridging the hole on the coil of many turns on the inside, and a coil inside of the wall. of so or 20 turns of heavy wire on the out- No other supports side.The inside coilis connected across or tying wires were the dynamo circuit, while the small coil is found necessary. in series with the main charging current. Fig. t shows The inside coil alone would not be sufficient the best method of for correct working.If adjusted to close the attaching the contactsat6. volts,then, once closed,it windcharger to the would not open again until the 6 -volt battery pole. Thefour is exhausted. On the other hand, if adjusted longbolts were to close at 7 volts,it would behave as a originally used for vibrator,sincethedynamo voltagefalls adjusting the ten- back almost to 6 once the points close and sionof a,wire connect it through to the battery. The mattress. The top steps,where one 5' 6" may have to stand forlongperiods,A view of the complete plant.The small blocks are made from flatseen along the front of the pole carry the copper iron ',bars,2in. byconductors.One row of climbing steps can be n ., projecting - seen on the right of the pole. from the pole forladder of similar height, and even the most about 6in.Theynervous climber becomes accustomed toit are spaced, like allafter attempting easy stages. thesteps,atan angle of about 120Conducting Wires deg. and are tilted The wires from dynamo to instrument slightly upwards. panel must be as heivy as possible, to avoid Four 6in. nails, orexcessive losses at the low voltage.In the long screws, absenceofproperrubber -coveredcable, holdthemin bare 7/22 aerial wire is quite good, and is position. The the cheapest heavy wire available.Those livinginalocality where thereisascrap -yard,or large garage at hand, should try to get sufficient copper strip for the job from field - coils of old motor -car self-

starters.The small starters /2' only yield lengths about 6ft., putonemaybelucky enough to find an old model with large coils. The author Fig. 1.-Side view and section offound an old " Hupmobile " the pole, shoWing method of attach-dynamo which supplied two ing the wind -charger. 3oft. lengths of flat fin. by Instrument panel. April, 1944 NEWNES PRACTICAL MECHANICS 229

Generator Thisratewillnotbe cut-out will not reduce the current 'through Lights affected whentheits own coil and calk it to vibrate. + -0/ " + - dynamo begins to charge, CI but will remain reason,. C2 ably constant even whenHouse Wiring thechargerisesto15 For wiring the lights, 7/22 aerial wire is amps.Two 2 -volt cellsvery convenient.For small hying -rooms, in series can be chargedtwo 12 -Watt bulbs suspended over the two simultaneously. The endMain " chair-poSitions " at each side of the Contactonthe" off fire,isa good arrangement. When only side of the rheostat goesone perSon is in the room, the second light to a bulb -holder. Ifa can be left off.With a large conical shade bulb which consumes 5made fromacircularcake -tinlid,well or 6 amps, is plugged polished,good readinglightisobtained it acts as an artificial load beneath a 12 -watt bulb. Two 24 -watt bulbs for high winds, so thatmay be kept at hand to be plugged in for the current reaching thespecial occasions. For passage -ways and storagecellsdoesnot halls, 6 -watt bulbs are quite sufficient, and vary so much. Thecan be mounted artistically under thick glass -I+ second last rheostat con- ointment jars with their lids screwed to the -IVolt Sto rage tact is the " off " wall or ceiling.For very small lights on Cells Cells position. Normally,'a 6 -voltcircuits, screw -incyclebulbs, con- Fig.2.-Circuit diagramof instrument panel. 6 -watt bulb in the holder suming 1.5 watts, arevery suitable. (B.) acts as a panel light,Itisadvisabletoeconomiseon power second coilis necessary so that the pointscontrolled by the switch Generator Lights are held in the closed position in spite of (S.3). A fuseinthe Holder (6) thissmall drop in voltage by the added chargingcircuit is a attraction due to the charging current nowsource of trouble, since 'flowing through theoutsidecoil. Whenit may cause the dynamoAutomatic Panel the charging current again falls to zero, the to burn out if it blows at .2 Volt Bulb Switch pointsopen,sincetheinsidecoilisno the beginning of a windyCharge Relay (S.3) longer abl_ to keep them closed without help night.A to -amp. fuse (C.2) from the outside coil.The connections aremay be included in the Generator usually marked clearly by one of the methods MainCharge Control Switch lightingcircuit,to pro- indicator illustrated in Fig. 2, but can easily be traced tect the battery. A slight (Al) (S./) by examination once the above is understood. alterationisneededin A 12 -volt cut-out with a weakened spring the conections of the cut- 2 Volt Charge will work on a 6 -volt circuit, but a 6 -voltout (C.2), but the wiringGenerator Indicator cut-out would heat up badly on 12 volts.diagram makes itclear. Voltage (4.2) The voltmeter is connected directly across The main ammeter (A.t) the incoming wires, so that it registers theis connected directly toAlain Cut -Out 2 Volt Charge actual dynamo ooltage under all conditions. the battery,sothat noany Fuse Box Rheostat The dynamo control switch (Si). stops thecurrentmayenteror (Ci) (R) dynamo generating by short-circuiting the leavethelatter without fieldcoils when changed into the secondregistering on the meter. position.Under these conditions the pro-Remember that the 2 VoltCharge peller " races " when the loadis removed, Generator On/Off Switch negativewiremustbe (S.2) so that the switch should not be used as an well earthed,preferablyStarting, Switch alternative to the brake rope !It is useful, at the foot of the pole, as (S.5) however, when one is changing batteries, ora protection from light- working atthe instrument panel,orfor ning damage.A t-mfd.Car Battery Lighting Circuit 2 Volt Cells emergencies to Protect the dynamo windings. Condenser across the Main Switch The push-pull switch (S.5) shorts the mainbruShes on the dynamo (s.4) cut-out points, allowing the dynamo to run will stop any radio inter- Fig.3.-Layout instrument panel. as a motor from the battery.Its main use ference. Seethatthe isfor testing the condition of the battery, 2 -voltchargingcircuitdrawsitscurrent wherever possible by using efficient tin or indicated by the battery voltage registered onfrom the positive line after the heavy coil ofotherreflectors,evenattheexpense of the voltmeter while the battery is supplyingcut-out (C.2), so that the operation of the appearance. 4 or 5 amps. to the dynamo.It is useful also when oilingthe dynamo or cleaning the commutator. Cut-out The cut-out (C.2) automatically switches on the 2 -volt charging circuit whenever the main charge exceeds 6 amps., or any other value for which the spring in C.2 is adjusted: In this way, the 2-1701t batteries will receive their current at a time when it can best be spared from the main charging current, and can be left connected for a week or so until their indicatorS register a full charge.The current delivered to the 2 -volt Cells is set by means of the rheostat (R.).This was made from the wiper of an old volume control moving over flat contacts cut from the brasS vanes of an old variable condenser.Short lsngths of issistance wire are attached from Contact to contact, the lengtbs being found by trial.The last pieces should be doubled or trebled to carry up to 6 amps, if necessary. The amineter A.2 has a full scale deflection of about 6 amps., and can be made by in- creasing the number of turns in the deflect- ing coil of an ordinary car ammeter.The needle isalso bent to one *le to extend U.S. naval officers aboard the flying boat Mars sit at the imposing control board which gives them the range. The switch (S.2) short-cirenits the a visual check on all vital aspects of the massive plane's operations. Mars, which has a wing I.ocond cut-out, leavingthe 2 -volt cellsto Span of200feet, and is the world's largest flying boat, was placedinThePacific service by the U.S. charge at a steady rate from the car battery. Navy last January. 230 NEWNES PRACTICAL MECHANICS April, 1944 BuildinAaSynchronous Electric, Clock Further Details of Construction and Bobbin Winding (Concluded froin page 185, March issue.) exposed to ensure a sound solderedWinding Operations union withoutprojectionof the Itconsistsof8oz.of No. 36 S.W.G. spindle end beyond thefaceofdouble silk covered instrument wire wound the pinion. on a bobbin which is a neat fit on the stator yoke.The bobbin is built up by wrapping The Idler Pinion stiffpaper, or very thin card, around the The pin on which theidler yoke until it is three layers thick. The end pinion revolves consists of a shortcheeks of the bobbin are cut from 3/16in. lengthof axlerod on which athick ebonite.They are 2in. square. The head is formed with the aid of acentral rectangular openings are cut with the thin,tight -fitting washer solderedaid of a fretsaw, taking care to make them a on. The poSitionof thisshort neat fit over the paper wrapping on the yoke. spindle,which onlypene-Secure the end cheeks in position with a tratesthefrontplate,is little celluloid cement or shellac.When the found by trial, using crimpedbobbin is dry slide it off the yoke and fitit paper strips togiveclear-on to a piece of wood, previously cut to the ance,asexplainedearlier.same dimensions as the yoke.Commence, The spindle issecured byand finish off the winding by soldering the means of a collar sweated on36 gauge wireto a short length offlex to the back of the gear plate. pushed through a Nilein the end cheek, A rear view of the finished clock To allow for adjustmenttaking care to insulate the joint with waxed of the hands, to thepaper or radio sleeving. The Spindle for the Hands correct time,the50 -tooth wheel on the Wind on the entire 8oz. of wire as evenly THIS spindle, which is driven by a 50 -minute hand spindle is secured to the spindleas possible, inserting a layer of thin paper tooth wheel secured to it, in a mannerwith a friction device, consisting of a six -between every few layers of wire. The paper to be described later, is journalled inarm star piece.(See Fig. 5.)Itis sawnwill assist in keeping the layers even.The the centre hole of the front gear plate.Thisand filed out of a small piece of springyexact quantity of wireis zot critical and hole corresponds to the rotor bearing in the brass,solderedto a collar, and the armsthere is no need to count the turns.This rear plate.The rotor bearing is, of course,bent to bear on the face of the wheel.Thewinding enables the clock to run for approxi- occupied by the rotor spindle, so, to providewheel hasits grub screw removed. Themately nine days for a consumption of one a rear bearing for the hands spindle, a smallwheel is prevented from moving away fromunit of electricity.When the windingis bridge is constructed, as illustrated, from athe star piece by having its boss in contactcomplete it should be covered with a wrap- couple of small pieces of angle brass sur-withtheybossofthefin.pinion whichping of dark coloured paper and doped with mounted by a small strip soldered on. Twodrives the 12 to i reduction train. celluloid lacquer. 5/32in. holes are drilled in the bridge feet, At this stage, the polishing and, if desired, The winding is again fitted on to the yoke and corresponding tapped holes are made inlacquering, of the brass parts may be under-and placed in position between the stator the rear gear plate.By drilling large holestaken.Clean up all the brass work withpoles.See that the transformer iron strips and using washers under the screw heads,fine emery cloth.When the polishingis bedneatly up tothe endsof the pole aswas done withthehorizontalplates,satisfactory, apply a lacquer composed of apieces so that there are no small gaps in the lining up of the bearings is facilitated. Thissmallquantity ofscrap,colourless,cellu-magnetic circuit. completes the drilling for the 22,500 toI loid dissolved in amyl acetate. Sixpence - reduction between the rotor and the spindleworth of this solvent will be sufficient for the of the minute hand. job.The same lacquer is also suitable forTesting Out The hour hand, which is secured to theapplying tothe face of the clock afterit Now connect the winding to the mains, boss of a gear wheel mounted on, but freehas been marked out, to prevent it finger-with a temporary piece of flex, and the clock to rotate on, the minute hand spindle,is marking. is ready for testing.Spin the rotor, with - driven by a reduction gear consisting of a The various parts may now be assembled.the aid of the fin. sprocket wheel secured train of 2 to 2 tot, and 3 to 1, i.e., Screwedrodscutintolengthsof3fin.to its spindle as a finger grip, gently round. 12 to I in all.An idle pinion is introducedprovide the means of securing thestator If everything is in order and the right start- into this train of gears to provide a reversalpoles and gear plates in their correct posi-ing speed has been attained the rotor will of rotation.Without thisidler the hourtions.Nuts and washers are used in prefer-continue to revolve. A few trials may be hand would revolve anti -clockwise. ence to distance pieces to position the variousrequired to get the knack of spinning it at A fin. pinion is locked on the minute -handparts, as they provide means of adjustingjust the right speed for starting. spindle.Itdrives a 50 -tooth wheel on athe spacing. spindle in hole C.This spindle also carries The Hands and the Dial a fin.pinion which meshes with another At thisstage, the front supports, which 50 -tooth wheel on aspindleinhole D.are similar to the rear legs, except that they .The hands are sewn and filed from thin The perforated plateisagain employed toare as high as the dial, can be made. Tosheet brass, and when completed they are position holes C and D, which are in bothensure that all the holes are in line, a longgiven a coat of black lacquer.The minute gear plates.A 2 -in. pinion on the spindlepiece of axle rod should be inserted throughhand has a collar soldered to it to secure it in hole D drives an' idle fin. pinion, whichthe holes in the back bearing strip, frontto its spindle. The hour hand has a piece of meshes with a 'fin. gear wheel on which isand rear gear plates, during assembly. tube, whose bore is a push fit on the boss of secured the hour hand.These last men- When the clock is completed and runningthe front 57 -tooth wheel, soldered to it for tioned two pinions and gear wheel are accom-it is, or it should be; quite silent.To showmounting.This tube should be aboutin. modated on the front face of the gear platethatit is running and therefore indicatinglong and,if a piece of drawn tube is not and it is necessary to saw off the bosses onthe correct time, an indicatoris provided.available, ,it may be fashioned from a strip the pinions and file them smooth.This isItconsists of athin.sprocket wheeltoof brass bent round the wheel boss. done so that the dial of the clock may bewhich is attached a disc of white paper, or The case alsogives room for personal brought sufficiently close to the gear,plate tothincard,on whicharepaintedtwo expression. The one illustratedisbuilt allow the boss of the rfin. gear to projectblack segments. 'The wheel is attached tofrom ordinary window glass, bound at the slightly through the dial. the spindlein hole A, the spindle beingjoints with passe partout.The construc- Thefin.piniononthespindle Dmade long enough to takeit.The wheeltion ofit was aided, greatly, by making a issecured to the spindle of soldering.Ifrotates at approximately 40 revs. per minute,rough cardboard box, the size of the inside the hole in the pinion is countersunk fairlyandasemicircularwindowin"thedialof the glasscase, on which to secure' the deeply, sufficientofthespindlewillbeallows it to be seen. pieces of glass whilst the joints were drying. April, 1944 NEWNES PRACTICAL MECHANICS 231 A LatheTreadle -wheel How to Construct a Serviceable Lathe Treadle -wheel in Wood By A.J.BUDD was next bored squarely through the bench leg -to take the axle bolt, which must he a push fit.The bolt was' tapped in place with a light hammer, after which a large iron washer was slipped on the axle and then the wheel. A smaller washer was then pushed on, and the position of the hole to,. take the steel split -pin D (Fig. 4) carefully marked.The wheel was then removed and the hole for the split -pin drilled, after which the wheel was replaced and secured by tit: small washer and pin,so that the wheel runs freely, but withlittle end play. It will be noticed that a fairly long bearing is provided for the wheel hub:thisisto prevent any tendency of the wheel to wobble, /61"

" Figs, i at d 2.-Front and side views of the completed wheel and treadle fitted to the bench leg and ready for use. HAVING acquired a small bench lathe,a push fitfor the tube A. the latter was andasan irontreadle -wheel forpressed in place, and the square plate fixed driving it is practically unobtainabletothe wheel *withthe four countersunk at the present time, the writer decided toscrews, as indicated in Figs. 4 and 5.The make oneof wood. The accompanyingflanged collar, B, was then pushed on to illustrations, Figs. r and 2, show the result ;the tube and. screwed to the wheel with the finished wheel and treadle have beenfor countersunk screws. r. inuseseveralmonths, and havegiven The crank -pin consists of afin. coach J trouble -free service during that time. bolt34, in. long, and thisisdriven into a tight -fitting hole bored through the wheel Weighting the Wheel at a distance of 2 -kin. from the central hole. For the wheel, an old pastry board ift. 6in.This allows of a treadlestroke of 41in., Fig. 3.-Method of marking out the wheel, square was brought into use.This boardwhich will be found ample for the purpose. and the holes for the lead weights. had been stowed away in a dry place forThe bolt is driven in from the flanged -collar over ten years, and proved to be a cleanside of the wheel, as shown in Fig. 4, thewhen running, and also to prolong the life and well -seasoned piece of dealtin. thick.squared part under the bolt head holdingof the bearing surfaces. On one side of the board a circle P61in.the bolt securely and preventingit from diameter was marked, and within this circleturning. Treadle and Connecting Rod another oner31in. diameter was marked, For the wheel axle, another *in. coach bolt, The treadle consists of a planed deal board as indicated in Fig. 3.Radial lines drawn61in. long, was used, the threaded part at22in. long, 4' in. wide and fin. thick.The from the common centre divide the innerthe end being cut off with a hacksaw, leaV-rear end of the board isbevelled slightly circle into 24 equal parts, and at the pointsing the bolt 51in. long under the head.Atand is hinted to a block of wood 6in. long, of intersection recessesslin. diameter andthe required height from the floor a holeas shown in Figs. 5 and 6.This wood block :lin.deep were made withacarpenter's centre -bit.The recesses were thenfilled with molten lead, and for this purpose odd piecesof lead piping and sheeting were melted down in an old aluminium saucepan, which was also used for pouring the molten metal into the recesses. The next operation was the cutting out of the circular wheel from the square board, and this was done with a coping saw, keep- ing as near to the marked circular line as possible.The periphery of the wheel was smoothed with a rasp. Wheel Hub and Crank Pin The wheel hub consists of three parts ; a central brass tube, a flanged brass casting, and a square end -plate, shown respectively at A, B and C, Fig. 4.The piece of tube is zin. long,;in. bore, and yin. thick, and isa push fitin the central hole -inthe flanged part B, which was bored tosuit. Fig.' 4.-Enlarged This part was also turned square on both sectional view of the faces.The plate C is a piece of sheet brass wheel hub, axle and *in. thick and 21 -in. square, with a centralfir ------crank -pin. hole bored a push fitfor the brass tube, 10" >i< to which it is sweated with soft solder. Having bored the central hole, in the wheelFig. 5.-Side and front elevations of the completewheel and treadle. 232 NEWNES PRACTICAL MECHANICS April, 1944 is screwed to an 8in. by 4in. board, which Soldered up the periphery of the wheel, and cut the in turn is screwed to the floor of the work- 13' >14aciV -groove fof the driving belt. shop at the required distance from the bench First, a rasp was used, and afterwards a leg which supports the wheel.The two 4-r1 coarsesand -paper block,pressurebeing hinges are, stout iron ones, withrlin. by applied whilst treadling the wheel fairly fast. rin. leaves. r A good deal of patience was called for during (is t The connecting rod is a planed oak strip * e = -'* this part of the work, but the result proved finished to the dimensions given in Fig. 7 ' satisfactory, and although the wheel did not and afterwards slightly rounded at the ends. 15V run quite as true as a lathe -turned one, it was The holes at the top and bone:n ends, to Fig. 7.-Details of the connecting rod. sufficiently accurate for all practical purposes. take the crank -pin and treadle pin respec- The belt -groove was cut with the aid of tively, are brass bushed, as indicated in thediameter for the shank of a ,No. so irona V -pointed tool, filed to shape from a piece illustrations Figs. 5 and 7.The bush (E)wood screw.The hole in the connectingof caststeel, which originally formed the for the crank -pin consists of a t2in. lengthrod is a tight fitfor the bush, which was screwed in place till the flanged end is tighttang end of a garden trowel.The wooden of stout brass tube, the bore of which is a handle of the V -tool was held firmly against good fit to the crank -pin. A piece of 3/32in.against the side of the rod. No other fixing is necessary. the apron of the bench, as shown in Fig. 8, thick sheet brass,. long and tin. wide, and the wheel treadled backwards. has a hole. drilled through the centre, a tight The top end of the connecting rodis Before commencing the cut with this tool, tit to the piece of tubing, which was pushedheld in place on the crank -pin by meansa shalloW guiding groove was formed round through andsolderedtotheplate,- afterof an iron washer and nut, as shown in Fig.5. The iron screw for attaching thethe wheel by pressing against it the corner adjusting for squareness.The hole in the of a square -section rough -cut file, the wheel wooden connecting rod is a tight fit for thelower end of the connecting rod to the treadle was passed_through the brass bush,being treadled at a good speed at the same bush, which is pushed in place and fixed time. with four round -headed ironscrews,theafter slipping on an iron washer.Another holesforwhichhavingbeenpreviouslywasher was then slipped on before the screw was driven into the side of the treadle. Driving Belt - drilled near the four -corners of the brass For the driving belt; two lin. diameter plate.The ends of the bush are, of course,Cutting the Belt GrooVe leatherbelts,as used for domestic sewing filed sqtaare The next pan of- the work was to truemachines,wereused,joinedtogetherto The bush at the other end of the connect- obtain the necessary length.' After connect- ing rod consists of a screwed bearing taken ing one end of each belt together with one from an old wireless component, the hole Side Front Back of the steel links provided, the belt was then through thehushbeingjusttheright placed round the treadle wheel and the larger 34" pulley on the lathe mandrel, and pulled fairly taut. The belt was then cutso that the Ir ends butted, and aftera hole Was bored 4 8"\,1 through near the cut end the othersteel linkwasinsertedandhammered. downs t< 22" t". Slightly to pinch both ioined ends of the belt. It will be noticed, with reference to Fig. 2, 6 bo that a hole is bored. through the bench, at y. the back of the headstock, to allow the belt to pass thrOugh. When in use all the bearings of the wheel Fig. 8.-How the belt groove was and treadleare kept well lubricated with cut in the wheel, and details of the machine oil, including the hinges at the rear Fig. 6.-Side elevation and plan of treadle. cutting tool. end of the treadle. R.A.F.MakeaRunway WORKINGinleather--jacketsand woollen caps as protection against the stinging winds of north-east Yorkshire, men of an R.A.F. Works Squadron transformed muddy grassland into part of an airfield in a few weeks. They tackle any airfield construction job in the shortest time, working long hours to break records and increase the Alliedair striking power. Here they extended a runway by 300 yards so thatit could be used by four -engine as well as two -engine bombers, and to make a new perimeter track around it.The land was first levellcd acid drained.Then the huge concrete mixer got busy dealing with more than three thousand tons of material each day. In 52 hours 5o men hadlaid2,000square yards of concrete 6in. thick., The Works Flight withitsbulldozer, concrete mixer, tractors, and giant trenching machine is part of an Airfield Construction Wing. There are many such wings working all over Britain speeding up the bUilding and improvement of airfields.

FROM MONTREAL IN 11.1 HOURS TWO LancastersoperatedbyTrans- Canada Airlinesinthe Government transatlantic service, have set a new record for lie Montreal to Great Britainflight, arriving respectively in II hours 16 minutes andt rhours14minutesafterledving Montreal. ThePreviousrecordwas ishoursInto the mixer tire wit shovel sand, stone and cement, Which will transforms the mud into a flat 35 minutes by a Liberator. concrete stretch. April, 1944 NEWNES PRACTICAL MECHANICS 233 The Proctor IV Particulars of the New Wireless Trainer for the R.A.F.

The 716V) Proctor IV wireless trahter THE Proctct IV is a three -seater low - of the designThe need for an 'economical The outer wings and centre section have wing monoplane with a zioh.p. De four -stealer communications 'aeroplane wastwo box spars connected at intervals by bulk- HavillandGipsyQueen engine, foreseen and when, after the first Proctor IVheads and spruce diagonal bracing members. designed to an Air Ministry specification as had bee -1 delivered, the deOgners were asked The contour is formed by wooden ribs and a wirele§S trainer for the Royal Air Force,about a communications version, they werethe leading edge is reinforced by plywood and the Air Branch of the Royal Navy. The able to provideit. These removal of over extending back to just behind the front spar. Machine is a successor to the Percival Gull 2oolb. of wireless training equipment alloWs The centre section each side of the fuselage and Vega Gull. for the carrying of an extra passenger andis covered with plywood froth the front spar Whey tr.war came the Percival Vegasome luggage in addition.The unit con-to the trailing edge to provide a wide walk- Gull was chosen by the Air Ministry forstruction of the seat bearer and control -unitway' giving easy access to the cabin. A conversion to Service use.Known as theassembly allow for conversion to a side -by -non -slip tread covers the whole of the walk- Proctor I, II or III, according to its duties,side dual control trainer in a few hours, way.The remaining covering of the wing it has been used for training or communica-Without any structural alterations. is fabric. tionsbyallthreeServices,inclimates Wooden split trailing edge flaps are fitted varying from those of Scotland to the WestGeneral Construction from the aileron to the side of the fuselage, Indies. Wood is used for the main structure with and arc operated by a hand lever in the The newtraineralthoughsomewhat metalfittings joiningthevariouscom- cockpit. similar in appearance to the earlier Proctors,ponents together, and plastics are used for isactually a completely re -designed aero-a large number of non -stressed and lightlyFuselage plane,bothfromtheaerodynamicand stressed parts.Synthetic resin glue is used The fuselage is built up with four spruce structuralpointofview. Inorderto throughout for bonding the wooden partslongerons, plywood sides and a pre -formed emphasise the differenceitwas officially together, and the interior is coated with sea-ply bottom skin.The top decking is ply- known, for a time, as the Preceptor ;but plane varnish, making the whole structurewood over laminated spruce frames and the it was later decreed that it should be calledpractically water resisting.With the largecomplete structure is fabric covered. the Proctor IV. inspection panels fitted at different part's of Hinged doors arefittedto eachside, The most noticeablethingaboutthe the structure maintenance and repair is easyallowing easy access to the cabin from the ProctoeIV,comparedwiththeearlier to carry out. wing. These doors can be readily jettisoned, Proctors, is a longer and deeper fuselage with in cases of emergency, by pulling down the tail plane set higher in relation to theWings leverS mounted in the roof. wing. . The wing is in three sections.. The centre From the operational point of view this portionofparallelchord and thicknetTail Surfaces new Percival trainer is much improved bycarries the undercarriage units and is bolted The tail planeisa complete cantilever the wider and deeper cabin, and by theto the bottom of the fuselage by four bolti.comprising ttf0 wooden box spars, ribs and lower engine cowling line.The pilot beingThe fuselage is recessed so that its under -Plywood covering.The complete structure seated wed forward has a very good view surfaceandthatOfthecentresection isfabric covered. . Itissecured to the over the nose and leading edge of the wing ; coincide.The outer wings taper in chord fuselage by two boltsatthe front spar this is important for deck landing, and alsoand thickness and are attached to the centreand one bolat the .ear spar on the centre when taxying on a crowded aerodrome. From section by stainless steel fittings.The piece line. his seat on the port side he can comfortablyof the wing aft of the rear spar and inboard The elevator has a wooden box spar, keep in view an aeroplane slightly in frontof the aileron is arranged to hinge upwards tpruce and ply ribs, and is diagonally braced If and below him on the starboard side, asallowing the wing to fold back pivoted atensuring a very stiff control surface. A would be the case when flying in formation.the rear spar joint. When the wings aretrimming tab is fitted to each side, operated The Proctor IV has been designed tospread a positive and fool -proof device makes from an irreversible unit on the spar. carry the full equipment necessary for train-sure that the bottom front locking pins arc The fin is of similar construction to the ing the wireless operators of our big bombers. inpositionbeforethetoppinscan be/ail plane.The rudder, of similar construc- The possibility of other uses for the Proctorinserted, and the gap, fairings cannot betion to the elevator, has a horn balance at IV has been kept in mind from the outsetassembled until the top pins are in position.the top which houses the mass balanced 234 NEWNES PRACTICAL MECHANICS April, 1944 weight. A trimming tab is fitted at the trail-oil tank of 3.8 gallons capacity is mounted assisted lever at the pilot's left hand, giving ing edge, with a similar control to that ofin the leading edge of the centre section on three positions ;flapsup,flaps one-third the elevator tabs. the port side.An oil cooler is fitted at thedown (for take off),flaps down.Each of inboard end of the tank, and faired into the these positions can be clearlyfelt by the centre section, with an outlet flap adjustablepilot, through the action of the self-locking Undercarriage plunger, so that there is no need to look ispositionedon the ground. A robust long travel unit The engine . canbestartedfromthe at an indicator. under each end of the centre section giving cockpit. The wheel brakes are operated by a hand a wide track (9ft. 9in.).Each unit eOnsists lever on the right of the pilot, with differ- of is cantilever compression leg, ineOrpOrating ential control worked by the rudder pedals. steel springs and a hydraulic recoil damPer.Controls th. The leg is attached at the top to a simple A special feature is the control unit and A bracket mounted from the centre -of the seat bearer assembly which forms a readilydashboard carries the throttle and airscrew casting which is secured to the front spar anadditional by four bolts.A streamlined fairing fromdetachable unit bolted to the centre section. pitchcontrollevers,and the underside of the centre section mergesThis carries the rudder bar, control column,throttle lever is fitted on the port side. intothe wheel fairing.A mudguard isbrakelever,fuelcock,fireextinguisher, fitted in the rear of the wheel fairing to compais and pilot's seat. A similar unit, butEquipment preVent Lige quantities of mud collecting.without the fire extinguisher, etc., is installed The cabin carries the largest type of wire- MediumpressurewheelswithBendixwhen the aeroplane is used for dual controlless sets as installed in operational aircraft. mechanical brakes are used. instead of wireless training. The pilots' seatsIntercommunication telephone equipment for are adjustable for fore and aft position, aseach member of the crew allows a wireless rail Wheel also are the rudder pedals.All controls are instructor in the rear seat to talkto the asfrictionlessaspossible,and although pupil or the pilot. Apneumatic tail wheel is attached to a'totally enclosed they are readily accessible A fixed aerial and a trailing aerial cover cast aluminium rocker arm hinged from the through the inspection covers provided. the whole range of wavelengths needed for bottom of the sternpost.Itis completely The elevator trim tab control wheel, with wireless training. The direction -finding loop rotatable and self centralising.The shockits indicator, is mounted in the roof aboveaerial on top of the cabin can be used for absorbing is by means of a steel spring, the instruction in flying on a wireless beam or recoil being damped by the use of a Ferodethe pilot. The rudder trim tab control, with itsindicator,ison the portside by thechecking position by taking bearings on two band: instrument panel. or more wireless stations whose positions are The split flaps are controlled by a spring - known.For training in visual signalling to Power Plant ships or to troops on the ground, there is A De Havilland Gipsy Queen II engine of an Aldis lamp stowed beside the rear seat. 2roh.p.,drivinga De HavillandCsmstant 250 B.H.P. De Havilland Gipsy Queen II Engine. The Proctor IV is completely equipped for speed propeller, is mounted in the nose of Span, 39ft. 6in. Length, 28ft. ails. Aspect ratio .. 7.72 night flying with the standard R.A.F. blind the. fuselage in rubber anti -vibration blocks Wing area 202 sq. it. flyinginstrumentpanel,cockpitlighting, on tubular steel bearers. The_ignitiOn system Wing loading .. 17.31b. per sq. ft. landing lamps in each wing, navigation lights Power loading .* r6.tlb.per B.H.P. is fully screened. A vacuum pump is fitted Tare weight with full equipment ..2.37o1b. and downward identification lamps. There for the operation of the blind flying instru- Disposable load . 1,130lb. are two cockpit lightsin the roof of the ments.A large generator is driven by the Maximum permissible all up weight ..3,5oolb. Top speed (sea level) .. 16o m.p.h. cabin above the pilot, one over the compass engine through the medium ofaflexible Maximum permissible cruising speed and one in the wall beside the rear seat. Each drive.The cowling is of robust design and (sea level) of these four lamps has its own dimmer comprises four parts, the nose panel, under Economical cruising speed (sea level) .. r40 m.p.h. Landing speed (flaps down) .. 55 m.p.h. Switch, so that the operator can adjust the tray, and two side panels which are hinged Rate of climb at sea level' 7o01t. per min. intensity oflighttosuittheprevailing on the top, giving coMplete access to the Time to reach 5,000ft. min. conditions. Ceiling . - 14,0ooft.

engine and greatly facilitating r.rtaintenaltoF. Run to take off no wind) .. 32oyds. When used as a four -seater communica- -A 20 -gallon fuel tank is mounted in each Run to clear soft. screen (no wind) . 65oyds. tions aeroplane the single rear seat is replaced outer wing, at the root end between the All performance florets are based on official by two rear seats which are so placed as to trials at the maximum permissible all up weight of spars. The feed pipe from each tank is 3,5oolb. give ample leg room and still leave space taken to a three-way cock in the cabin. The for light luggage. Probes and Problems Here are Some-J\Aore Mental Nuts for You to Crack (Solutions are given on page 246) A Matrimonial Medley candidite received votes from three others.job was brought off. Bill Basher told me he'd \Vhat is my name ? had nothing to do with it.cs ,- Messrs. Smith, Brown, Jon4.and Lop -Ear : " I've got a perfectly clean Robinson each married the sister of one of record. As a matter of fact, Slogger Joe the other three men.The Christian name A Calendar Problem and I were together when the stones were of Mr. Smith's wife is Bessie. Katessin'aiden In each normal year January z comes onepinched." name was Jones. Hilda married Bessie'sday later in the week than in the preceding Tommy the Toff : " It was Bill Basher who brother.Mr. Brown's sister married Mr.year :for example, January r, 1943, fell on atold me about the robbery.Lop -Ear was Robinson. Friday, and New Year's Day, 1944, was ahanging around Lady Croesus's house all What was Jane's maiden name ? Saturday. But when there is a Leap Yearthat day." Electing a President the difference is two days-so that January r, Slogger Joe :" I've never been near the 1945, will be a Monday. place.It's queer that Grabstein seems to The five members of our fpotball. club Bearing in mind that century years arehave had plenty of dough lately." committee met last week to clloOse a Pre744nf;Leap Years only if the first two figures are Bill Basher :" The Slogger always rats 9n but the election proved a fiasco.4araldivisible by 4-that is to say, the- year 2000his pals.I suppose you know that Tommy rule is that each member of the ciatkItteewill be a Leap Year, but 2100 will not-howthe Toff has been down for a stretch ? " has five votes which he can distributas helong before the first day of a new century is likes, with the sole proviso that he must nota Sunday? Rather puzzled by these conflicting state- give any votes to himself.Well, we had to ments,the, inspectorconsultedwith an adjourn without a President, becaise We all Assistant Commissioner at the Yard. got the same amount of support. Who Stole the Sapphires ? " A man doesn't lie unless he has a guilty Bloggs received all my votes ;he ,was the Five suspects were interrogated about theconscience," said the Commissioner." You only candidate thus to receive a mixitinain.theft of Lady Croesus's sapphire necklace ;may rely or it, Inspector, that all these men Clark gave the same number of votes to eachfor the inspector in charge of the case knew for,,except the criminal have told the exact truth." of two candidates, and received equal votesa positive certainty that one, and only one, " Oh, all right, sir," replied the inspector. from each of two members as well.Everettof them was implicated in the affair. " If that's the case I can lay my hands on the favoured Clark most highly, and Bloggs giVe They made the following statements : guilty party right away." all his votes but one to Adams.Only one Grabstein :" I was at Brighton when the Can you ? April, 1944 NEWNES PRACTICAL MECHANICS 235 Engineer -built Houseso

(Continued from page Plfr *zit the Future -14 161, February issue.)i

Double and Composite Partitions : Flat Roofs Double and Composite Paftitions By R.V. BOUGHTON, A.I.Struct.E. This means that the 2in. dimension of the THESE are eminently suitable to allow posts must be laterally supported at vertical for good principles of pre -buildingof four 4ft. wide units with posts at aboutintervals of 3ft. 4in. and 5ft. for such ratios, and may be made capable of not only2ft. centres.Each post will have to carryand a study of the details will show that supporting considerable loads of floors anda floor area of 6ft. x 2ft., equals 12 F.S. at,this is quite practicable.Even allowing for roofswithaninconsiderableamount ofsay, z cwt. foot super to cover dead weightnon -axial loading on the posts due to the material, but, as well, give excellent oppor-of the floor, and a superimposed load offloor, it is obvious that quite small scantlings tunitiesforthe provisionof useful cup-4olb. F.S.This gives a load of 6 cwt. Themay be used for the posts, such as sizes boards,cabinets,wardrobes,sideboards,area of roof, which is supported by the uppervarying from 3M. x 2in. up to 4in. x 2in. bookcases and shelves.Fig. 86 depicts onepartition, which transmits the roof loads to The compositepartitions,despitetheir examplewheresuchpartitionsmaybethe lower partition, is also about 12 F.S.,overall thickness, which makes them very designed and constructed to ensure manyand, although the superload may be 301b.stable and resistant to buckling and overturn- structural and equipmental advantages.Inor 5o lb. (as described in the last article),ing, must be anchored securely at the bases the example it will be noted that the parti-depending on whether the houseisbuiltto the floors and fixed firmly at their tops. tion is situated between the main front andOutside or insidethe London area,itis Figs. 87 and 88 show typical plans of back rooms of an ordinary two -storey smallreasonable to again allow 6 cwt.This makesthe partitions.Instead of the doors to the house-its situationis where the ordinarya total of 12 cwt., and as the dead weightvarious fittings being hung on butt -hinges, traditional load -bearing partition is built ofof the partitions must be covered,letusthey may be horizontally sliding doors ; the brickworkbetweenthedining -roomandassume that 15 cwt. must be supported by whole of the fittings are capable of being lounge in the ground storey and the fronteach post.If the posts are 3M. x 2in. anddesigned and constructed in many ways to and back bedrooms in the first storey.Athe slenderness -ratioisbased on the2in.suitanyreasonableneedsandaesthetic subject for argument may be in connectiondimension,andthetimberisordinaryrequirements. with the difference in thickness between anungraded redwood, each of such posts will . ordinary or single partition and the compo-support safely about 36 and 19 cwt. withRoofs site type shown by Fig. 86.The argumentslenderness -ratios of 20 and 3o respectively., Roofs of engineer pre -built houses are of in favour of the latter is that, in addition Tyre, F-4-wrsaw 9310rz to doing heavy structural duty, it gives much useful equipment within its thickness, which , equipment, if of the ordinary kind of furni- ture, projects into and takes up a considerable amount of space in the room.Therefore, it is just to contend that some, if not all, of the space occupied by a double or composite partition may make it practicable to reduce the size of a room by the amount of space Sf..CTION used in the partition for cabinets, etc.As an example, the side of the partition which faces the dining -room may be equipped with the equivalent to the traditional sideboard- li it may have drawers initif desired-or there are cabinets and cupboards of a 'useful c. character,allof which would save much expenditure on furniture. The partitions may be factory produced in lengths of, say, up to 4ft. and of a height equaltothe height of eachstorey. If deemed expedient, eachsection could be made and delivered in a few units which could be quickly assembled at site ; in fact, there is a variety of ways in which design and construction can play good parts. The parts of the composite partition which are subject to structural loads need careful ...J. ..i, attention, those parts being chiefly the main Nv. posts which have to carry floor, roof and 41.4,31,1,14 other loads.The general design permits the T1 MOM posts being made capable of carrying quite heavyloadsbecauseofthe number of horizontal, longitudinal and transverse mem- bers which may be employed in the general structure. No postneedhaveahigh slenderness-rao, and consequently the per- missible stresswhich may be imposed on the posts can be reasonably high.Let us investigate this important structural matter in regard to the partitionin the ground It Aili41111 storey, which has to carry greater loads than FART ELEVATION Cr that in the first storey.Take one row of COMPOSITT-. PARTITION Aki4of --1 ii1 9111.}15}Miiiii posts only-those which have to carry part 2 9^ PAR.T V_CTION THROUGH HOUSE- a of the first floor, part of the roof and some FRcHe 1.17,3Z3N1T \v/A4J_ AN) LOAD of the superimposed partition, .asFig.86. HCAR.ING COHIP051TE_ PARTITION There isno need tobe' pedantic inthe 86.-COMPOSITE PARTITIONS AND FLAT ROOF. A-Structural posts. B-Rails. investigation, so letit be assumed that theC-Shelf. D-Bearer. E-Linings. F-Sill. G-Composite beam. H-Side of panelled unit. room is12ft. from wall to the partition andJ-Metal corbet extending through beam to form bearer for panelled units. K-Roofing material. 16ft.in the other direction, which meansL --Boarding. M-Joint cover. N-Packing laid to falls.0-Joists at junction between units. that the partitionist6ft.long, consisting P-Part section and elevation of composite beam. 236 NEWNES. PRACTICAL MECHANICS April, 1944 considerable importance and interest as theythere are so many window and door open-panels can be used,tci suit dimensional varia- gisrefullscope to the designer and con -ings, corners, projections, stairs, fittings andtions of several inches in the width of a s1 actor to provide a general design whichother items, that dimensional co-ordinationhouse.The main structural twin members Will appeal to varying xsthetic tastes andwill do one of those things which thosemay be- placed at from about 2in. to about allow for the use of many kinds of struc-antagonistictopre -buildingpredict,viz.,6in. apart, thereby giving up to ain. variation tural and roofing materials.. The traditionalcause too much monotony in planning andto every, say, .eft. centre of the beams, which types of pitched house roof consist of thein zesthetical design.I am equally convincedwill necessitate only varying the width of timber framework withitsrafters, purlins,that the vast post-war programme of housethe framed -in soffit member and the upper struts,ceilingjoists,ridges,hips,valleys,building -400,000 houses atleast yearly-packing member and cover strip. binders and hangers ;therafterssupportwill tempt those interested in pre -building Flat roofs must be formed so as to provide battens or boarding on which are laid thou-to provide a reasonably large range of unitsfalls to the upper surface to drain off rain- sands oflittletilesor slates ;the ceilingto suit most practical requirements of archi-water, most roofings requiring a fall of not joistssupport theceilingcovering, whichtects and builders.On this assumption, flatless than tin. in loft. or t in 6o, and this May consist of thousands of feet of lathsroofs can be designed as almost completelyis not too much if it is borne in mind that nailed with thousands of nails and the lotindependent of some of the dimensions ofsuch practical matters as alittle deflection covered with plaster, or the covering may,thewallandpartitionmemberswhichin the roof, seams over joints, can easily be of building boards. Gutters, flashings andsupport them. nullify such fall and cause pools of water otheritems,completetheroof. These As flatroofs have to span rather con-which all good designers endeavour to avoid. traditionalpitchedroofsareexceedinglysiderabledistances which depend on the Fig. 86 shows roofing panels of reasonable heavy, and they are costly, and if not con-sizes of rooms, some of which are of widthswidth and length, but of varying thickness structed properly they exert forces whichand lengths varying from, say, t2ft. to t6ft.,toprovidefalls. This system ofdesign tend to overturn walls.The traditional typeit is manifest that roof panels Of such lengthsensures a level ceiling.The general frame- of flatroof is structurally better than thewould be rather unwieldy, but that beamswork of the panels consists of narrow -width pitched roof described above. ofsuchlengthsare much moreeasilytimber members covered on the upper side Engineer -built roofs designed in accord-handled. Therefore,forflatroofsitis with boarding, and, ifdesired, sound and ance with the best codes of practice willconsideredthatpre -builtbeamsoflongthermal insulating material, and with any of ensure strong,light -weight, weather -resist-lengths and comnaratively small panel unitsthe many kinds of impervious roofings which ing, long -lifeand economical pitched and shouldbe employedtoachievethebestwill be described in the future article.The flattypesofroofs. Theroofsshouldresults. underside of the panels may he covered with conform with essentials in connection with the following:(t)stability,(2)durability, (3) transportability, (a) resistance to rain, etc., (5) thermal insulation, (6) sound insulation (rain beating on roof), (7) economic initial cost,(8)economic maintenance costs,(9) speed and ease of erection, (to) light weight, (ii)good appearance,(t2)fireresistant, (13)avoidanceof condensation, and (4) 1"42.1- VAT=.7 OF PART1'7: J space for, and protection of, water cisterns, V pipes, etc. Fig. 87 Fig. 88 Fig. 87.-A-Structural posts:B-Posts at vertical junction of partition units.C-Linings. Flat Roofs D-Doors. Fig. 88.-A-Structural posts.B-Posts at junction of units. C-Linings. D-Doors. This general type ofroof,used either entirely to groups of houses or alternated withpitchedroofsoracombinationof pitchedandflatroofs,isamatterof a. ststhetical design.Butitisconceded by many designers that the -flat roof with OW Cr' MANY A4.-TERNAtIVE. METHODS Cr FLAT overhanging eaves and with proper propor- QCLDF5..tl-A,1 AND PANLLS SLT TO etc.,can tioningofwallsand windows, Fig. 89.-FLAT ROOF WITH BEAMS AND PANELLED UNITS SET OUT OF LEVEL. provide housesofvery good appearance. Apart from this, all persons connected withTO PROVIDE FALLS TO ROOF. A-Beam. B-Roofing, etc, C-Small section roof joists. the- design of engineer -built houses should D-Ceiling lining. appreciate the fact that the public do like Fig. 86 shows one of the simple types ofany of the many -varieties of building boards. traditional buildings, and this liking shouldflat roofs.The loads of and on the roof Fig. 89 shows a principle of construction be met to a reasonable extent. The ordinaryarecarriedprimarily by built-up beamswhich is well worth attention.The wholp pre-war type of flat roof to houses consistedwhich support panelled units.The beamsof the robf structure is set out of level, which of timber flat roof joists laid level with taperare of particular importance not only as tois a principle that may shock those designer or other fairing pieces to form falls, and on theirduty of carrying the loads, but towho like level lines and do not realise that thisstructuralfoundationwaslaidroof the fact that their width can be varied bysuch lines are often undetectable and of little boarding and flat roofing of asphalt or built-a few inches to allow for the use of stan-interest to those who live in the rooms. Such up felt roofing a/1d the underside celled withdardised widths of the . panelled units ; theya method of construction allows for an equal lath and plastering or building boards.This arethe means by which standard widththickness of the roof units. construction provided an excellent roof, as did other types of flat -roof construction, such as of reinforced concrete, patent roofs, etc. Of course all these methods of construction Items of Interest caused much more site work than is neces-Bread Cutter Fighting 8 Miles Up sary for pre -built systems.There are many IT is reported from Washingtonthat a new good systems of flat -roof design and con-TN institutions and other places where larae -I- quantities of bread are consumed, for version of the P 38 Lightning, now being struction which will be explained inthismany years it has been the custom to sliceproduced, capable of fighting in thin Air series, and in this article itis advisable tothe staff of life by means of a machine. eight miles above the earth while rnanceuving discuss general principles based on two of athit/hispeedsinescortinglong-ranie the systems shown by Figs. 86 and 89. To perform this work without at the samebombers, as well as making its ,own bombing I am not yet convinced that dimensionaltime slicing the fingers of the operator is missions. co-ordination of the various units of floors,theprincipalobjectofabread -cutting It has a service ceiling " well in excess of walls, partitions and roofs will be satisfac-machine, for which a patent in this country40,000ft." and . the new Lightning is" a tory.I believe it will be found that variationhas recently been applied. dog-fig'iter which can out-mani:euvre many in dimensions of the units for the different single -engine planes." main structural parts, and no definite rela- This machine includes a conveyor tionship of the dimensions of such units,arranged to carry the bread or other articlesArtificial. Gems as in walls, with those of other units, suchin succession past a driven rotarysliciri ARTIFICIAL sapphires and rubiesare as in roofs and floors, will provide a muchcutter. And thereis means designed to beingmanufacturedintheUnited greater freedom in designing sizes of roomsimpale the articles in order to retain thepiStates for the war industries. and their disposition in the general planningin place upon the conveyor while they are 'with the cutting off of the natural gems system, than by trying to make the widthsbeing sliced. from Burma and Siam, it became necessary ofallunitsto certain defined standards. War -time bread, however, does not lend tomanufacturesyntheticgemsusedin This belief is intensified by the facts thatitself to slicing by machine. precision instruments. April, 1944 NEWNES PRACTICAL MECHANICS 237 A Watch De -magnetiser Its Construction and Operation By J.L.- WATTS THE steel partsof watches areliablebe diverted towards and through any pathThe Coil to become magnetised if the watchof high permeability such as the main spring The coil should be wound with 6116. of isbrought within a magnetic fieldofthewatch when brought withinthe3o s.w.g. enamelled copper wire.A single such as exists between and around the polesvicinity.Such a weak field, of course, wouldinsulated wire from a twin lighting flexible of a permanent magnet as used on a magnetohave no permanent effect on the watch, butleadabout2ft.longshouldbepassed and certain types of dynamos ; and in thethe diversion of the field would cause thethrough one lead in hole of the bobbin and vicinity of an electromagnet such as theneedle to be deflected by the watch, as wouldwrapped round the bobbin, leaving about field magnets of a dynamo, electric brake,any other unmagnetised piece of soft iron. gin. of lead outside.The coil end of the or other electro-magnetic apparatus which It should not, therefore, be assumed thatlead should be firmly secured with tape and is fed with direct current. A magnetic fielda watchismagnetised merely becauseitsoldered to one end of the 3o s.w.g. wire. surroundsany conductorcarryingdirectdeflects the compass needle.Should suchIf a latheisavailable, the bobbin can be current, the strength of field being propor- mounted onamandrelforwinding, or tionaltothe currentflowing, when the possibly a wheel brace secured in a vice magnetic field does not pass through an iron could be used.The coil should be wound or steel path, so thata watch may even as evenly as possible, the finishing end being become magnetised by coming too near to ...... Solderedto anotherflexiblelead brought a cablecarryinga heavy directcurrent, 5p Die through the coil cheek ; the coil then being although the strongest magnetic fieldsare 21'64 finished by taping and, if desired, a cord usually found near coils having an iron core. binder. It is wise to keep all watches away from Itisuseful, but not essential,tofit a such magnetic fields,as a watch may fail small neon bulb and small bayonet type of to go at all if the steel parts become strongly insulated batten lamp -holder on the base- magnetised so that the balance is attracted -. -3 k boardtoindicate by nearby screws, etc., or the hair spring whenthesupplyis 4. switched on.The two coil leads can then is attracted to the balance.A weaker state be connectedacrossthe lamp -holder,to of magnetism in a watch may lead to erratic Details of the hardwood bobbin. which can also be connected a twin flexible running, and bad time -keeping.Watches a deflection occur, move the watch into suchlead of the required length for connecting having cases of iron or steel tend to deflect to a lamp -holder any extraneous magnetic field through thea position that a maximum deflection occurs, through whichthe then move the watch straight away from theapparatusissupplied. Alternatively,the caseitself, and thus screen theinternal flexible lead could be connected to a two- pais to a large extent. needle.Keeping the watch well away frompin plug if the suitable plug socket is wired Once a watch has become magnetised itthe needle, move it round and approach theup. A switch is not fitted on this apparatus, is practically impossible to remove all tracesopposite end of the needle with the samewhich must therefore bg isolated from the of the magnetism, as this would necessitatepoint of the watch.If the opposite end ofsupply by removing the plug or lamp -holder heating the steel parts to redness, re -harden-the needle is equally attracted,it may be assumed that the attraction is due to neutraladaptor, or by" switchingoffat the fixed ing and polishing them, and renewing small switches, when not required for use.The parts such as the balance and hair spring.steel parts of the watch. On the other hand,reason a- switch is omitted is that a lamp - -r if the second end of the needle is repelledholder adaptor and two -pin plug are not 'CompassNeedle away from the watch and the needle tendspolarised, that is, they can be fitted in two Brass Clip Coil/ to turn through 18o degrees, so that the first Soldered to Neon Lamp ways. There is,therefore,ariskthat a Nut ehd of the needle is again attracted to the Watch,itisevidentthat some steelpartsingle -pole switch on the apparatus might of the watch has a definite magnetic polarity,be connected in the neutral pole instead of and the watch should be treated to remove the magnetism.If the compass needle is placed with itscentre over the centre of To Lamp Holder the balance shaft of a magnetised watch, the Adaptor or needle may vibrate through an arc as does -Pin Plug the balance, or may swing round and round.

Constructional Details Diagram of connections. The followingnotesdescribethe con- struction of a watch de -magnetiser suitablethe live pole, in which case the coil might for operation from a zoo to 250 -volt 5o cyclebe at 23o volts above earth when the switch 04 Hole 2-4- 04Hole 2 A.C. supply.The baseisfirstbuilt up,was off. .2.0ia Hole in Base using a piece of hardwood about gin. by A brass rod ;lin. diameter and 3in. long General arrangement of the de -magnetiser. 611 -in. by =in. thick, this being walled round formsarigidsupportforthecompass underneath with wood stripsin. thick byneedle when testing the watcheS.The rod Fortunately, however, a watch can usuallytin. deep, to provide a recess for the con-isscrewedfortin.from one end and be made to work quitesatisfactorily bynections.The next step is to construct theclamped to the baseboard with a brass nut removing nearly all the magnetism. bobbin, which can best be turned up fromand washer on either side ;the top of the hardwood to the dimensions given.Ifitrod is screwed tin. for a brass nut, to which Testing for Magnetism isnot possible togetthis turned up,itissolderedabrassclipfor the compass A small compass needle can be used tocould be made in parts which were after-needle.This arrangement allows the maxi- testthe watch for magnetism.For thiswards well glued together.The obviousmum freedom of movement to manipulate purpose itis best to use as small a needlemethod is to use plywood or other thin woodthe watch round the needle.After testing as possible, as such a needle will have afor the coil cheeks ;whilst the tube couldthe watch the compass needle should be low moment of inertia and be more likelybe of wood or cardboard, or might be builttaken out of its clip and removed to a safe to respond to a moving magnetic field.Theup with several thicknesses of good qualitydistance before switching on, otherwiseit type of compass needle which used to bepaper impregnated with shellac varnish.Itmay become de -magnetised as well as the fittedto such noveltiesassmall mirrors,is not advisable to attempt to make a metalwatch.The currentisthen switched on pencils, and pencil sharpeners, obtainablebobbin, as the varying magnetic fluxsetand the watch held in or near thecoil, for a few coppers before the war, will doup in the coil would then induce a voltagebeing turned round and over fora few very well.Various points on the watchintheconducting bobbin sothateddytimes.After a few seconds the current is should be brought to one end of the compasscurrents would flow and heat up the bobbin.switchedoff, by which time any serious needle in turn and any movement of theTwo 3/i6in. diameter holes are drilled indegreeofmagnetismshouldhavebeen needlecarefullynoted. Itshouldbeone of the coil cheeks for the wood screwsremoved, and the compass needle can then remembered that the magnetic needle itselfwhich secure the coil to the base, togetherbe replaced on its stand for any further tests has a weak magnetic field, and this field willwith two smaller holes for the coil leads. required. 238 NEWNES PRACTICAL MECHANICS April, 1944 A Miniature Hand Loom An Easily -made Machine for Weaving Cloth inside t h e central central frame over, so it will suffice just to frame. Screwtheinscrew this up astightly as possible.The in just far enough_to four vertical rods inside the central frame are bring them the rightmade of straight lengths of round brass or distancea par tto steel i,in. diameter ; they are not -fixed other- allow them to fit wise than by being a tight fitin the holes nicely ontheguide drilled for them at top and bottom. Each rod rods. should be -4n. from its immediate neighbour The wires to carry and sin. from the wooden frame when fitted the warp threads so that they may be withdrawn by means a should now be made ;a pair of pincers when necessary.These only one of theseis rods form guides for the "healds " or frames shown in Fig.4 towhich lift or depress the warp threads._ avoid confuSion, but This will give us 20 warp threads per 6o are required,30 inch on a- piece of cloth 3in. wide, like that for each heald. seeninFigs.tand 2.The method of The weft is pressedmaking the wires is shown in Figs. 5 and 6. tightly into place byDrive two nails about 3/32in. diameter into means of a comb -like a piece of wood, so that they are 3 13/16in. affair termed a apart, centre to centre, and cut off the heads ; " reed,"afterwhich then take, a piece of wire about yin. long, the warps change lay it round the two nails and twist up the over, the lower onesend for several turns to form a long loop, as shown in Fig.4. Now make another coming to the top andjig with two nails and a piece of wood exactly as before, except that the nails should be only 3".in. apart this time. Adjusting the Wires Fig. 1.-The Lay the loop on the new jig and put a finished model hand loom. short piece of r/ 16in. wire through the loop LOOM is oftenregarded as a complicated piece of machinery, but A the model described below is really quite simpleto makefromeveryday materials, and req*es the use of only a modest set of tools.A certain amount of patience is needed in making a few parts, but one is rewarded by the fascination of working the model and seeingthecloth grow as the weaving progresses. The illustration, Fig. r, ,gives a good idea of the complete model ;the finished cloth A specimen of cloth -woven on the hand loom. with a check pattern can be seen on the rolleratthefront.The longitudinal or and twist the loop up by means of the " warp " threads are wound on to the roller 1/r6in: wire tillall the slack is taken up, at the back and pass through thehealds F/is. 3 and 4.-The construction of the healds,as shown in Fig. 5.Give one or two extra to the front roller.These rollers are called and (below) the method of making the wires. turns to make the wire taut, but not enough beams," that at the back being the " warpvice versa, ready for the shuttle tolaythe to break it.It is better, perhaps, to twist beam " because it holds the warp threadS, nextthreadofweft, thus while the front roller is the " cloth beam."building up the cloth thread As the weaving progresses the finished cloth by thread'as the operation is is rolled on to the cloth beam and the warp repeated. It is advisable to is unrolled from the other. readthisshortdescription carefully in con- Forming the Cloth junction with the To for.n the cloth alternate threads of the illustrations t o StOrs -f-CeeP warp areliftedor depressedto forma get an idea of the " shed " or wedge-shaped opening through working before which the shuttle is passed, leaving behind beginning c o n it the transverse thread or " weft." struction. Start by The Wooden Frame making the main Fig. 3showstheconstructionofthe frame, as shown healds, two of which are required.The in Fig. 2. This wooden frameisof the simplestpossible_isjustasimple description, all the four pieces of wood are pieceofwood- alikeandarejustscrewedtogether,- as work all screwed shown,withtinyscrews. A touchof together ;skilful Seccotine on thecorners before screwing joineryis not togetherisan advantage.The horizontalrequired for this wires are/16in. diameter and a tightfit so long as all the in their respective holes. A knitting needleparts are planed does very well for these wires.They should exactly .square. be exactly 31in.apart and 'quiteparallel. The brass Care should he taken when making the frame diagonal struts that the screws are not put in a positionare necessary on where they are likely to get in the way ofthe four corner posts to prevent theI /r6in. wire. The screw eyes in thethem from being pulled over 2.")( Bas Si X side members should be small ones they by the tension on the warp, but ''T" 8 have to slide up and down the vertical rodsthere is no tendency to pull the Fig. 2. -The main frame... April, 1944 NEWNES PRACTICAL MECHANICS 239 one or two up until they break so as to getThe Reed and Prattle agoodideaof how muchtwistingis Next make the reed anditsframe,as required, then you can stop just short ofshowninFig.g. The wooden partis breaking point afterwards.When finished,simplicity itself, the bottom is cut off on a the central eyelet should be in a plane atslant at each side to allow it to rock freely right angles to the eyelets at each end (seeon itshinges.The metal frame is made Fig. 6).Twist the wire in the same direc-from 4in. by t/r6in, strip brass, the hori- tion on both jigs, otherwise you may findzontal members being6in.long and the yourself in difficulties. vertical ones 3in. long. The wire should be 28 gauge soft brass Take the two horizontal members and or copper, or 28 gauge enamelled copperclamp them together in a vice, then make .a" electrical wire will do very well ; leave abouta cut about 1/32in. deep in the centre of ,,'in.of the twisted end on, as shown inthe length with a fretsaw (don't use a hack- Fig. 6, the rest may be snipped off. saw, it will be too wide).On each side of Draw back the t/ 16in. wires on the healdsthe first cut, r ',in. away, make another ; this and thread on 3o of the twisted wires, thenmakes three.Halfway between each -make If push thet /i6in. wires back intoplace ;another. cut (giving five nicks in all), then Fig. 7.-The operating fevers for lire kcalds. they should fittightly in the wood.Thego on halving the distance between each twisted wires should be able to move aboutuntil you have 65 nicks altogether in a spacethrough the tape on the cloth beam ; thread freely when fitted, so as to be able to takeof 3M.Separate the two pieces, solder up single strand of the wool through the reed, up their own position when the threads arethe frame at the corners and drill a bolethen through the first eye of the front heald, in place.The healds may now be fittedat each corner for the fixing screws.Nowafter which pass the needle through the tape to their guides in the main frame with theget some 28 gauge hard brass wire (don'tof the warp beam.This makes thefirst horizontalwoodenmembersoutside as use soft copper or enamelled wire for this),warp thread.With the woolstillin the shown in the photos. needle leadit, back through thefirst eye Next make the operating levers for the of the back heald, then through the reed, healds, as shown in Fig. 7.Two of these in the opening next to the first thread are required ;they. are just strips of r/ r6in. leave one wire between the threads) and brass soldered together, the end being twisted se -cure the end to the tape of the cloth beam, to make a convenient handle. taking care that the tension is as near as practicable equal in both threads. The Pivots Thismakesthesecondwarpthread. These areordinarybrass wood screws Thread theneedleagain and repeatthe soldered on and the threaded part cut off, above sequence of operation, of course using after which a t/r6in. hole is drilled for a the next eye in each heald, and the proper split pin.Screw the levers on to the top openings in the reed, thus completing four horizontal member of the main frame by warps.Fix two more wh4te warps, making means of a single screw which forms a pivot. six altogether, then change the white wool One lever should be on the front at the left for the black and set up six black threads. and the other on the back at the right, the -,1e" Brass.\., Continue setting six white and sixblack, inner end of each lever --reaching to the centre alternately, until the width Of the loom is line of the machine.Connect each inner Fig. 8.-De, filled.Take care to keep the tension as even tailsofthe as possible, otherwise the wara may break tnd to its respective heald by means of a later on ;also keep the threads as nearly simple link like Fig.8. The top end of this link goes on to the pivot soldered on parallel as you can. to the lever and the bottom end is screwed - 11 Now take up the warp beam and, by to the top of the heald by means of a single turning it in the hand, wind all the warps screw, which must not be screwed right on to it in such direction that they run off home. tilt top side of the beam towards the loom, and fix the beam into .itshearing.Do not Now make another link like Fig. 8, but let the side threads spread outwards on the long enough to connect the vertical members beam while winding them up, or they will of the levers- together ;this link will have be too slack when wound ; guide them in to be about 5M. long, but it will be better towards the middle slightly as you turn the to measure off the exact distance on the job beam.Fit one or more rubber bands round and make the link to suit.When this link the beam and catch the other end of the isfitted and held inplace by split pins,Fig 6.-The central eyelet should be in a plane at right angles to the eyelet at each end. bands on the hook provided on the base, to either lever will move both healds, so that give the required tension.This should be when one heald goes up the other goes down.: carefullyadjustedbychoosingsuitable Fix a screw into the side members of theif the wire is not hard when bought you can harden it by stretching it ;fix one endrubber bands, for if the tension is not suffi- main frame to limit the movement of theof the wire by twisting it to the frame, thencient the warps are likely to cling together, so levers, allowing the healds to move ;in. above wind it over and over the frame, one wirePreventing the formation of a clear " shed " and below the centre line,i.e., each healdin each nick u all the nicks have a wiretopass theshuttle through ;but, on the haS a total movement of r tin. in them andsurethe end of the wireother hand, if the tension is too great, some fx temporarily.Wind the wire with moderateof the warps may break, causing considerable tension only ;if wound too tightly the frametrouble to the amateur weaver. will bend inwards and the wires first put -it 11 II II ISH on will -be found very slack.Now solderThe Transverse Threads Gofr all the wires firmly to the frame. Turning our attention now to the " weft " Brief instructions for weaving plain clothortransversethreads,twoshuttlesare were giveninthearticledescribingtherequired, one wound with black wool and construction of the Hobbies loom, but cloththe other with white.Take up a position having check and stripe patterns can alsoat- the front end of the loom so that the he woven on this loom. shuttle can be entered into the shed with 11111 one hand and withdrawn conveniently with MIHM 1110111 To produce this kind of cloth, first obtainthe other.Move the healds (one up and four twopenny cards of darning wool, twoone down) by means of the operating lever, black and two white.Of course, you canand see if a good, clear shed is formed by choose other colours if you prefer, say, brownthe warp threads ;ifthe warps show a and white, or light and dark brown. tendency to cling to one another owing to projecting fibres of wool catching the neigh- Setting the Warp Threads bouring warp, move the reedtoand fro Set the first six warp threads as describedonce or twice.This will probably effect an in the previous article by temporarily fixingimprovement, butif the shedisstillnot the warp beam about a yard from the loomwell defined, add more tension by altering (or fartherifa longer length of clothis the rubber bands. required).Them thread a length of about Hinges 2 yds. of white wool into a darning needle,Moving the Shuttles Fig.. 9.-The reed and its frame. knot one end of the wool andstitchit Now, with the reed pushed hack toits 240 NEWNES PRACTICAL. MECHANICS April, 1944 for the exercise of his ingenuity in produc- 51" ing other patterns.For instance, with the warp set as above, and one shuttle only in use, a cloth with longitudinal stripes would result.Transverse stripes can be obtained ° Tape 4"Long - 0 flttic. o 0 by using two shuttles, with warps all of one - _ colour.Smaller or larger checks and stripes are, of course, made by changing the colour Fig. io.-Details of the "beams." of the threads (either warp or weft, as the case may be) more or less often than every limit, take one of the shuttles, say the white After weaving six white threads, leave the six. one, and after unwinding a few turns ofshuttle laying on the base and weave six It is not possible to obtain herringbone er wool, pass the shuttle through the shed sothreadsofblack,andcontinue changingtwillpatterns on a loom with two heald as to push the weft right up into the angleshuttles after every six threads.There is noframes, and the provision of three or more of the shed.Next, return. the reed toits need to cut off the threads when changingwould complicate the model considerably. backward position and change the positionshuttles. of the health.If necessary, move the reed After you have woven an inch or two of If desired, other material than wool may to and fro to clear the shed, then pass theclothyou will findthe shed gettingtoobe woven into cloth, say silk or cotton. shuttle back again from left to right, but dosmall to allow the shuttletopass freely. notpull the wefttightly.Pull the reedWhen thisoccurs, wind the newly -made forward to drive the weft home, and whilecloth on toits beam by turning the beam Slots tr Wide X / Deep the reed is still in its forward position, drawtowards you, of course lifting the flat spring the weft through untilit folds neatly overon theleft while you doso,afterwards the extreme warp thread.If you do not domaking sure that the spring catches one of this, the selvedge (i.e., the edge of the cloth)the pins again before you let go of the cloth will probably be uneven and untidy.Afterbeam. a little practice you will find that you canProducing New Designs 4" carry out the whole procedure quite quickly. The amateur weaver has plenty of scope Fig. i L-The shuttle. MakinaParzta raph A Useful Instrument for Copying Drawings APANTAGRAPH is a simple tail by its size, insert the screw -eyes into the holessquare.Then place the point 8 on arm meansofwhichyou maycopy, marked 3, and upon tracing over the draw-X level with the point 8 on arm W, and by enlargeorreducedrawingsanding with the tracing point, the pencil willmeans of . the square scribe off the position illnstrations.The device shown in Fig. traceoutthedrawingthreetimestheon arm W on to arm X. You will then be consists of the various parts shown in Figs. 2original size. Aite certain that the positions are correct. When itisrequiredOperation Screw into small to reduce the size of a Wood Block under drawing,thepositions In using the instrument let the left hand of the pencil andpress on the tracing point and the right Ann 2 Arm X tracingpoint must behand graspthepencil. Now guide the reversed, and forthistracing point over the drawing to be copied, purpose a short,and at the same time exert a slight pressure stumpy piece of pencilon the pencil. As the tracing pointis should be pushed overmoved over the drawing the Pencil will thetracingpoint,draw ow an enlarged copy Of the original. and a piece of round Ann 2 ironpointedatone Wood Block end, and of the same I" x 4fr" x size as the pencil, shouldbepushedin the pencil hole.The various letters in Fig. i Tracing correspond to those zrx 4"x 1*" Screw Eye ' Point ThisBlock fixed shown in Fig. 2. Fig.3. -The Fig. 5. - An Fig.4. -How to Drawing Board Tracing Point Itisabsolutely im-block for clamp- or di nary the tracing Fig. i.-The pantagraph completed. The assemblingof the parts portant, if accurate scaleingthe panto- screw - eyeispoint is made. is clearly shown in this illustration. copying is to be done,graph tothe used w h e r e that the distances of thedrawing board. show in Fig. 1. to 5.Use strips of oak ?fin. wide and 1,in.holes from the points A, C and B (Fig. 2) thick for the four arms, and carefully markshould be carefully marked out. To ensureYou will probably find at first that the pencil offthe distances shown in Fig. 2.Drill this, place the arms W, Y and Z togetherlines are wavy, met this is because the pencil the holes shown to accommodate the screw -andscribethethreeoffat once with magnifies any false movement of the tracer. eye illustrated in Fig. 5.

At the point A a little bar of wood is I attached, as shown in Fig. 3, so that the Arm W effr endofthepantagraph canbe screwed 6° down to the drawing -board.The tracing %"'1-4[6-1- t; 1 point C consists of a nail with a washer 192" soldered beneath the arm X to keep it in 2 6 -8 place ;the nail should be filed up to a Arm X ---oC sharp point and serves as the tracing point. ifr6%1 '4; I VI To accommodate the pencil a piece of -1 4' wood is glued over the end of the arm Y, 164" as indicated in Fig. 2, and a hole is drilled Ann Y -e8 in it of a size to suit the diameter of thc Positionsof Holes in Arms Y 8 Z are same as in Ann W We to pencil. The other joints are made cleat take pencil from the drawings. Wood Block 11;x Vx ei" Am? .o .=. Enlarging and Reducing Glued to Ann To enlarge a drawing to, say, three times Fig. 2.-How to mark out the four arms of the pantagraph. April, 1944 NEWNES PRACTICAL MECHANICS 241 Inventions of Interest By Dynamo" Safety :Pocket connecting link at these points between theforn/ed by a bandsaw or any other suitable sides and bottom and lid and ends of a tool, TO guard against lossisthe aim of apacking case or crate. self -closing safety pocket for which A further object of the invention istoPneumatic Gun Firer an application for a patent in this countryrendertheplywood impermeabletothe has bee -I made. penetration of moisture, insects, etc. THERE has been accepted by the British Itis affirmed that even when this im- Patent Office an amended specification peccable :eceptacle isinverted its contents relatingtoimprovementsinpneumatic are perfectly secure.A U-shaped spring The information on this page isspecially means for controlling thefiring,reloading suppliedto" PracticalMechanics "by engages the pocket at the edge and resiliently Messrs. Hughes & Young, Patent Agents, of and safety blocking' of automatic guns. holds closure members in taut condition. 7, Stone Buildings, Lincoln's Inn, London, Previously it has been proposed to effect This safety pocket can easily be incor- W.C.2, who will be pleased to send free to these three functions by pneumatic cylinders readers mentioning this paper a copy of their porated in or as part of a garment.For handbook, " How to Patent an Invention." on a gun.In that case the circuits were exampleit may be used as a breast pocket controlled from a distance or from a signal in a sports shirt or as a trousers pocket. central station for a whole series, of guns. As a separate articleof manufactureit Cheap Chessmen The aim of the improved deviceisto can answer the purpose of a purse. place at the disposal of the occupants of an SINCE mediaeval days the pieces occupy-aeroplane simple means for reliably ensur- Dish Washer ing the chequered board have beening thefiring,reloading,or simultaneous madeofavarietyofmaterials. Thesafety blocking of the various firearms on THE washing of dishes is a necessary but aristocratic sets have been formed of ivory. board. not always a welcome practice.An But the pieces have often consisted of wood Aceording to the invention, a pneumatic inventor has been devoting his attention toand sometimes even of paper. And fullcontrol of aeroplane armament consisting of this subject and has devised an improvedsized human beings have been known to actseveral arms, such as machine guns, has; method of cleansing quickly and effectivelythe part of chessmen on a Brobdingnagian interposed between the source of compressed a large quantity of crockery and domestic board. air and the cylinders, allotted tothe gun utensils. An inventor has recently conceived thetriggers, and preferablylocatednearthe His plan concerns the kind in which aidea of chessmen which can be furnishedlatter,a gun -selectordevice. This device casingLasinitslowerpartseparate cheaply in large quantities from inexpensiveconnects up inthe pneumatic circuit the reservoirs for cleansing and rinsing, while and readily available materials. selected gun or guns to the exclusion of the in the upper part there is a receptacle for thearticlestobe washed firstwith the cleansing and, then with the rinsing liquid. The deviceis characterised by the fact that a casing containing inits lower part two reservoirs, a motor, a pump and time - control means, has its upper portion divided into aseries of superposed compartments, each with its own door. A common delivery pipeleads from the pump toallcom- partments.There is a valve in the pipe for each compartment and the arrangement is suchthszonstarting up ofthemotor, cleansing liquidisfirst pumped from and returned to ene reservoir.Then an auto- matic change -oversuppliesrinsing water from and returns it to the other reservoir. Easy Unloading TO facilitatethe discharge of loads by gravitation-in plain English to provide an improved tip cart, waggon or lorry-is the object of a new device which has been submitted to the British Patent Office. This invention relatesto vehicle bodies of the type which tip automatically when they have been moved backwards to a point at which the load overbalances. Included in the design, pivotally segued to the chassis of the vehicle towards its tear, is a short underframe upon which a bodyThe first mobile camera, " The Dinosaur's Eye," for taking mass X-ray pictures of lungs, in the can: slide.Normally this body is carriedMinistry of Health's drive against T.B., is now in use touring factories in Britain. It is an outsize only partly by the underframe. The remain- camera, and consists of a network of flexible metal tubing, a high tension transformer, and adjustable ing or forward portion is on fixed supportsstand for persons being photographed.The illustration shows the film being !Arced in the special on the chassi, on which itslides to and camera which takes the pictures of the lungs. from the position of overbalance. "The method of manufacture comprisesothersin such a way that one operator, cutting a strip of wood, or other appropriatewithoutalteringhisposition,canbring To Strengthen Plywood substance, by a milling operation to conformabout numerous varied firing combinations. THE reinforcementof plywoodisthe to the contour of the respective pieces andAnd this he does by acting on one-and chiefobjectofarecentinvention. slicing the profiled strip transversely.Thealways the same-control number.Thereby The plywood is formed of two or moreindividual slices are then mounted on stouteffective communication isestablished be- layers of thin, narrow strips of wood of low discsofwood,to which they may between the source of compressed air and the value placed with the grain at a right anglepermanently secured by glue. selector. in the' separate layers.Between two of the An interesting alternative is to shape each A CORRECTION layers thereisatleast one sheet of thinslice in such a manner that it will dovetail metalorwaterproofedfibrousorotherwith the disc and be detachable.The discs IN the article on "A Printer Enlarger" waterproof material.The layers and thecan then be available for playing draughts. which ispublished in the February sheetarefastenedtogether bystapling, In the making of these chessmen, notches, issue, page 148, the formula for the distance nailing or similar means. such asfor example, the gap between the " lens to negative " was given as x = f. This The sheet extends beyond the sides andears of the horse's head of a knight andshould read x = f + m f. ends of the layers, in order to form a flexible the division in the mitre, of a bishop, can be 242 NEWNES PRACTICAL MECHANICS April, 1944 The Story of Chemical Discovery Tracin the MissinElements Sidelights on an Intriguing Field of Chemical Research THE Periodic Table constitutes one ofinvestigated and were found to approximatecover/ at the present juncture, but one of the fundamentals of chemical science.with extreme closeness to those ofthe important consequences ofit was that It was originated some seventy years Mendeleeff'spredictedeka-boron. Againit became possible to give to every element ago (in1869, to be exact) by the famousthe famous Russian chemist had triumphed. a number beginning with No. 1 for hydrogen Russian chemist of the former city of St. At the end of the year 1885, another ofup to No. 92 for uranium.This number Petersburg,Dmitrii Ivanovitch MendeleeffMendeleeff's predicted elements was broughtwas termed the " atomic number."It was by name. to light.Dr. Welsbach, of Berlin, investigat-found to be an even more fundamental factor Readers who have followed this presentingasulphideorefromaminenearthan the atomic weight of an element, for series of articles on chemical discovery willFreiberg, Saxony, discovered thatitcon-this number was shown to represent the have gained an insight into the nature oftained anunknownconstituent,whichnumber of revolving electrons possessed by this remarkable " natural "classification ofconstituent ultimately turned out to be athe atom. Thus Element No. 6 (carbon) has the chemical elements, whereby every known six" planetary "electrons surroundingits element is accurately codified, ticketed and centralnucleus, ElementNo.47(silver) pigeon -holed in a comprehensive " table " or possesses 47 planetary electrons, whilst, say, scheme according to its individual properties Element No. 26 (iron) is equipped with 26 and those of its compounds. of these " outside -the -nucleus " electrons. When Mendeleeff' firstpropoundedhis The most interesting thing about great Classification Scheme of the elements Moseley's discovery of atomic numbers was there were only 63 known elements.For that this system of numbering the elements this reason he was obliged to leave many served to confirm the amazing accuracy of blank spaces in his table, which spaces, all Mendeleeff's " PeriodicTable." More- of which represented then unknown over, it showed at a glance the number of elements, would, he hoped, be filled up as " possible "elementsbetween hydrogen timewent on andasfurtherchefnical (Element No.t) anduranium (Element discoveries were made. No. 92),the lightest and the heaviest of Amongthe heaviere 1 e nt ent s in the elements respectively.By comparing Mendeleeff's originaltable of1869 there the number of" possible " elements with werenumerousunoccupiedspaces,- but that of " actual " elements, the number of among the lighter elements, such as boron, " missing "elements becamecleartoall aluminium, silicon and others of relatively concerned. low atomic weight the number of vacant Since the days of Moseley (he was killed spaces representing " missing elements " was during the Gallipoli campaign of the last much fever. To three of these hypothetical war) the number of " missing " elements or missing elements, Mendeleeff gave the has set up a sort of -provocative challenge namesofeka-boron, eka-aluminium and to many a chemical investigator, with the eka-siliconrespectively, the prefix " eka " resultthata very considerable amount of being the Sariscrit numeral " one." work has been carried out with a view to Fromacarefulstudyofthe known discoveringallthe missing elements and elements whose names were adjacent to the thusto" complete "thenowclassical spaces representingthe threemissingAn experiment on the vaporisation of iodine,Periodic Table of Elempnts. elements, Mendeleeff proceeded to predictthe fourth of the known " Halogen" elements. Thetrailingofthemodernmissing the characteristics and properties not onlyElement No. 85 should turn out to be the " fifthelements forms one of the most interesting of the unknown elements themselves, buthalogen" when it is discovered, but it has notchapters of present-day chemical discovery. also of some of ,their compounds.This was yet been conclusively found. It is a chapter, too, which is not yet com- aboldstepfor any man totake,andnew element, to which, in honour of his plete,for,although,atthe present date, Mendeleeff was, in some scientific quarters,fatherland, the worthy Welsbach applied thetraces ofallthe unknown elements have derided for his chemical prophecies. name of Germanium. Itwas notlong been reported by different academic investi- before germanium was found to coincide ingators, satisfactory confirmatory evidence in Gallium and Scandium properties with Mendeleeff's " eka-silicon,"a few instances has not been forthcoming. Mendeleeff'striplepredictionwasan-for it is very much like silicon in character- One ofthe' first modern discoveries of nounced by him in 1871.Three years lateristics, and is, indeed, only half a metal. missingelements was made about5925, (in 1874), Lecoq de Boisbaudran, "a French For a long time germanium was one ofwhen indications of the material existence chemist, happened to examine a specimenthe rarest of metals, of natural zinc blende (zinc sulphide) in thebut, about the middle spectroscope.He found in the spectrum ofof the last Great War, the mineral a then totally unknown brillianta new mineral, named blue line.Suspecting at once the presencegermanite, w a sdis- of a new element, he forthwith proceededcovered. This con- on an analytical trail, the eventual result oftains amongother his investigations being the discovery of a things, about 8per new element --a metal-to which, in honour cent.ofgermanium of his country, he gave the name of gallium.togetherwithabout Gallium'spropertieswereascertained.r per cent. of gallium, They were found to coincide with Men-a fact which resulted deleeff's eka-aluminium. Galliuin was ingermanium be- actually,in fact,theprophesiedcha- aluminium. coming a commerci- In1879; a Swedish investigator namedally obtainable Nilson was engaged in chemically extracting product. the constituents ofarare mineral calledAtomic Numbers euxenite. He foundinitan unknown Just previous to the ingredient which gave risetoahithertolastwartheyoung unknown spectrum.Further investigationsphysicist Moseley, of were carried out and another new elementManchester, made a was given to the world.Again this wasdiscovery of prdfound a metal, to which Nilson gave the nameimportance. It is ofscandium,inallusiontohisnative impossible to go into country.The properties of scandium werethe details of this dis- A glimpseof amodernchemicalresearch laboratory. April, 1944 NEWNES PRACTICAL MECHANICS 243 oftwo manganese -likemetalswerefirstto it a happier name than the one whichhad made, seen or handled a lump or even clearly shown.Mendeleeff, before his deathit bears at the present time. a mere grain of metallic virginium.And, in 1907,hadpredicted,amongother to make thingsmoreconfused,another elements, the existence of two metals whichAn American Discovery investigator, H. Hulubei, came along some he named eka-manganese and dvi- In 1926 Professor Smith Hopkins, of theseven years later (in 1937) with an entirely manganese.The later introduction of theUniversityofIllinois,togetherwithhisfresh claim to the discovery of the missing atomic numbering of the elements showed co-workers, Drs. Harrisand Yntema,alkalimetal(ElementNo. 87),which thateka-manganesecoincidedwiththeannounced to the world the discovery of aelement he proposed to name Moldavium. unknownElementNo.43,whilstdvi-new element which they claimed to have Hence, virginium and moldavium are still manganesewasapparentlythesameas detected in monazite sand.Hopkins nameddisputedentities,althoughvirginiumhas unknown Element No. 75. theelement Minium,inhonourofthecertainly found its way into the American American State of Illinois.According tochemicaldictionaries and other works of Rhenium results obtained from X-ray spectrum work-reference. Whether, however,itwillbe Two Germans, Noddack and Tacke, ining, the new element, illinium,correspondsreplaedatafuturedatebyanother 1925, announced that they had discoveredwith the missing Element No. 61. " Element No. 87 " is, at the present stage, At approximately the same time,Professorquite impossible to say. traces of the hitherto unknown elementsRolla, of the Royal University of Florence, Nos. 43 and 75 in certain platinum ores.Italy, published astatement tothe effectThe " Fifth Halogen " To Element No. 75 they gave the name of " Rhenium," ih allusion to the western dis-that he had, two years previously, obtained A perhapsstill more interesting " miss- trict of Germany (the Rhineland), and toindications of the existence of the missinging "element is thefamous" missing Element43theyinparted the name ofElement No. 61, to which element he pro-halogen." The " halogens " (Greek :hals; "Masurium," a name which was intendedposed to apply the name Florentium, after salt "; genes," producing ")comprisea (with characteristic German stupidness and hisnativecity. The recordofRolla'sgroup of four well-known, closelyrelated -inanity)tocommemoratetheGermanSupposed discovery was deposited in a sealedand highly reactive chemical elements, to defeatoftheRussiansintheM'asurianpackage,whichwas receivedintothewit, the elements fluorine, chlorine, bromine district of East Germany during the periodcustody of an Italianscientificsocietyinand iodine: of the last Great War. No discoverer otherJune, 1924, and the seal of the package was Now, in the table of " possible " elements than a German would have endeavoured tobroken in Novem- fasten on to an element a title so reminis-ber, 1926, after the cent of bitter memdries.Nevertheless, theAmerican an- name "Masurium " still stands. discoverynouncement of ofthe Rhenium, during the last decade or so,illinium. has become an almost common element. Rolla's claims Sortie of its compounds are even listed inWere apparently chemical catalogues. This is becausediscredited..A n d rheniumisassociatedinNaturewitheven Professor molybdenum compounds. Hopkins's illinium Metallic masurium has never been isolated. is, as yet, no clear- Nor have any clear-cut compounds of thiscut element.For element ever been prepared.Noddack andone thing, neither Tacke, the co -discoverers of masurium, statemetallic illinium that one part of this element is containeelnor any of its com- inio,000 partsof native platinum, but,pounds have ever according to a number of Russian chemical beenobtainedin investigators, neither masurium nor rheniumweighable are to be found in native platinum oresamounts.All that orinthe chemical concentrates of thesewe know about the Sodium, the commonest alkali metal, is so soft that it can be cut with materials. existenceof a blunt knife.Whether clement No. 87, the missing alkali metal, will illinium is through be found to posiess such a characteristic remains to be seen. Element No 43 the evidence (and rather uncertain evidencethere is a place for a fifth halogen, to which In view of the facts that between the yearsat that) of X-ray spectra. It is quite possiblethe name eka-iodine has been applied. Eke - 1877and192oatleastfoursupposedthat illinium is a fantasy, and that Elementiodine, the missing halogen, corresponds with "elements " were successively put forward 6i is still at the present daya missingthe unknown Element No. 85. as correspondingtothemissingekai all events, if illinium does happen About 1932 a group of American scientists, manganese (Element No. 43), and thatall to exist,it must be one of the scarcest ofheaded by Dr. Allison, claimed to have dis- these claims were proved to be unfonnded,folepient, far exceeding the rarity of radium.covered the missing halogen element. one is still justified in coming to the conclul They The Miksing Alkali Metal christened it Alabamine, from the State of sionthat Element No. 43,the supposed Alabama.It was extracted from monazite " Masurium," is still, in strict reality, a very lg-pd the present-daymissing elementssand residues, and it was examined by spec- much missing element.Letis hope, there- isAt unknown alkali metal.It comprises troscopicand magneto - opticalapparatus. fore,thatifsuchisthecase,thefinalElesnent No. 87.The tern eka-caesium wasBut, once again, alabamine in the mass, that discoverer of this elusive element will impartformerly given to it,since, in Mendeleeff'sis to say, material which could be weighed, ' Table of Elements, it was woefully lacking. wasgivenaplace The chemical world is apparently near the metaldivided ini3 two camps over the question caesium in the alkalipf alabamine, Element No. 85. One section group 9f metals. of opinion assertsthat the original claims In I90 a couple offor the existence of this have been American investigt;made good.The other section holds that tors,Messrs. Allisonwhen you peer into a spectroscope or into and Murphy,stated a Magneto -optical apparatus, and are not that they had foundquite sure that the lines which you see are clear evidences of th real or imaginary (owing to their faintness) existence of eft then, under these circumstances (which seem caesium (Elenientto have prevailed at the supposed discovery No. 87) by spectro- of alabamine),pyou are not justified in stating scopic methods. Theythat you have found something new. called the new Thus, to all practical intents and purposes, element Virginium,the verdict in the else of alabamine, Element aftertheAmericanNo. 85-thefifth halogen "-isthe good State of Virginia.old Scottish one of " not proven." But, somehow or other, more satis-Anglo-Helvetium factoryproof of It was only last year that Element No. 85 virginium's truewas again in the news.This time, it was existence was notpresented under the absurdly cumbersome An analyst's work bench in an up-to-date 1 at, oratory. forthcoming. No one (Continued on page 246) 244 NEWNES PRACTICAL MECHANICS April, 1944 MakingaSuccess of Your Photography More Uses for Your Camera. By JOHN J.CURTIS, A.R.P.S. THE above title will appear to be ratherthe subject is ? " he inquired.I replied:modern, includingthosewith marble or facetious to many of my readers in" I was not good at guessing," and he then.wood surrounds, plain and carved, small arid these days when itis so difficult toinformed me that it was the works of a watchlarge.For some years there has been a obtain supplies of films and papers for usingtaken with the back open.Apparently hecraze for something Original or out of the in the ordinary ways of amateur photography,was very interested in watches and clocks,ordinary, and builders of houses welcome but, fortunately, these restrictionsare not.and in order to make himself familiar withany designs with a touch of originality and permanent fixtures, and we hope that theythe works, and so to be able to do repairartistry. Forsmallhouses,thebuilt-up will become much more elastic in the latterwork, he would photograph each layer ofbrick type isstill very popular, and itis part ofthisyeal. Further, thesearticleswheels and other parts during thepossible for anyone with aflareforthiS on photography are not intended for thedismantling. 'work to Make" a fair income.One method present day only ;they are written in the To me this application was quite a newisto procure several photographs and to belief that those who read them will acquiredeparture, but I can readily understand how,colour the bromide prints with Johnson's infotmation,1hintsandadvicethatwillby means of a series of prints made fromphoto tints to suit your own ideas, then to enable them to become more progressive andone's own negatives of a clock's works ormake composite drawings, using parts of the familiarwiththevariousprocessesandthe wheels and gadgets of any intricate piecedesigns of three or perkaps only two of the applications of the art of photography. of machinery, it would be possible to gainoriginal photographs ;in this way it is pos- With these thoughts in mind let us forsufficient knowledge to be able to successfullysible to design a brick or tile fireplace with a few moments consider the many uses to a wood or store surround.The finished which photographyisbeing put inthese design should then be photographed and times we all know something of what the coloured and submitted to the builder, who Air Force, Army and Navy are doing with would pay a fee if he made use ofit,or the camera.Thousands of films are being a series of such might be accepted by the exposed daily for use in the training and actual makers of fireplaces. instruction of men and units, in reconnais- sance work over territory occupied by the Aids to Decorating enemy,inresearch work inthe medical When the Far isover there are - many sections,andstatisticalrecordsarebeing who will want to try their hands and skill made and checked in large quantities by the atredeccrating their homes, and amongst clerical departments, -but probably only a otheritemsthequestionofgrainingof very few of us know or realise how very Panels and &Ors may claim attention ;an importantithas become in most of our expert graifftr is not eaiy to find, but itis leading industries. possible to make a collection of photograph's of the various types of grainings, such as Photography in Industry walnut -- burr ;and straight - oak,rnap1R, Itis now recognised as a leading- factor Mahogany,etc.,andittheseprintsare in the daily routine of most of our large coloured to give the right effect they would engineering works, and thousands of pounds give the amateur the right baSis op which and hours of labour are being saved by the towork,andthepaintsupPlierwoylll use of still .photography and cinematography,' advise what paints are necessary to use for anditcan be honestly be assumed that the door, panel or cupboard to obtain the hundreds of lives are -saved by the use of best rendering. radiography-a very close relative to photo- When plain papers for wall coverings took graphy-for examining raw metalsbeforeA good photograph of the works of an alarmtheplaceofthehorribleuniformfloral being fabricated ; also for parts, sections and clock. decorated papers, the makers of papers had joints before assembling an' aeroplane engine, theideaofsupplyingcut-outslikebik machine or other valuable plant. repair the same when anything went wrong." scraps " of birds, trees and other devices Shipbuilding, locomotive construction,For purposes of identificationthe printsfor pa jing on the wall to relieve the Plairt- architecture, farming and agriculture, can-might be marked with figuresorlettersness or barenisi, but the scheme didnot. ning of foodstuffs, banking and insurance,indicating each unit so as to ensure it beingcatch on for a long time, and so supplies and many other departmeng concerned withreplacedcorrectly,especiallyuseful wherewere stopped.isloW, however, thereis our existence and daily life, are now findingtwo or more items were similar.This is ademand, and itis practically impossible to photography is almost a necessity, becausemethod thatisquite commonly usedinobtain any of the designs, but the amateur it helps so much in speeding up production,actual practice in many engineering shops,photographer can make, his own.I have in the elimination of mistakes, in the makingand at two recent exhibitions in London,seen a nuisery made beautiful by photh- of true records for future planning and esti-one of a well-known make of motor and aero-graphicenlargements,tintedwithphoto mating, and in many other ways facilitatesplane engines, the other of a' complicatedtints, of teddy bears, golliwogs, penguins, the work and solvesthe problems whichpiece of machinery forcutting screws ofpigeonS and other items which always appeal inevitably occur in large organisations. varyingdegreesoflength,thickness andto young children.The bathroom walls of But how doesthisinterestoraffectthread, photographicenlargementswereanother hov.s.e were distempered a pale blue, ordinary individuals who are using photo-displayed for the benefit of the public inand the owner, being a keen amateur, made graphy merely as a hobby or asa spare -order that visitors could get a better under-two or three enlargements of some clobd time occupation ? standing of the workings. negatives, the prints were suitably cut and Some may know and have had experiencetrimmed, then pasted on the walls near the Lantern Lectures of the difficulty of getting a typewriter satis-ceiling, then be made other enlarged prints Well, the best answer that can be givenfactorily repaired ;it takes several years toor' seagulls on the wing, and these Were to such a question isto relate a personalmake a reliable and skilled repairer, becausearrangedinsuitablepositionsbelowthe experience which occurred only a few daysthere are in the average machine about 3,040clouds. Itiscurioustonotethatthis ago.It happened whilst with a party ofparts,together with38oscrews. Beforedecoration had tie effect of making that bath- friends on a short ramble ;seeing a cameraattempting to dismantle your typewriter, Iroom appear much larger than it actually is. slung on my shoulder, a stranger approachedsuggeSt therefore you take a series of photo- me who also had a camera,' nd soon wegraphs and continue to do So during eachRadiography were relating our experiences.He provedperiod of the dismantling.It may be the One short note for those who have photo- to be very keen on giving lantern lecturesmeans of making you a skilled operator, andgraphic knowledge, yet through circumstances with his own slides, whenever time anditshouldhelptoovercome thetroubleare not able to pursue their hobby. A friend, opportunityserved,atthelocalliterary,which crowns the efforts of so many of uswell on in years, offered his services to his debatingandothermeetings,hischiefWould-be amateur mechanics of finding atlocal hospital, he had very little knowledge of subiects being English landscapes. On occa-the end of the job that we have more partsradiography, but was prepared to learnif sionshe showed oneslideofatotallythan when we started the work. he could be of service.To -day, after about different subject, one of which he was very Another veryinteresting work forthetwo tothree years'casual work, he has proud because of its high technical quality,camera which to my knowledge has provedbecome almost an expert, andisgiying and which alwayscreatedgreatinterestits value already in many directions is thevaluable aid to those who are very much among his audiences." What do you thinkphotographing of fireplaces, both ancient andoverworked. April, 1944 NEWNES PRACTICAL MECHANICS 245 THE WORLD OF MODELS By "MOTILUS" TheLizard Lifeboatand Its

Model . . . A Large -gauge Model RailwayEnthusiast,and the Work His Models are Doing for War Charities recently on business, I had the opportunity ofvisitingthe exhibitioninaid of the Merchant Navy Comforts Service, held at the Ritz Cinema there during Merchant Navy Week. I found there not only some quite good specimens of model ships of every type and description, but also an excellent display of larger gauge model locomotives, the work of Mr. Ernest Dove, of Sherwood, Nottingham.

A Cornish Seaman and Model -maker

somethingthSinTgEPpfaNchSa'raoctferCiand Coirtnh Fig. 1.-The lifeboat of 1V1.R.wall.He is one of eight brothersthe Lizard outside who, in peacetime, were all connected withher station. As will be the littlevillage of Cadgwith and ' the life-seen, sheislaunched boats of the Lizard. down a slipway. His first service in a lifeboat was in 191t, when these gallant little vessels were of the pulling and sailing type.In 1913 he joined 2.-The lin. to the foot model of the " Duke of York" lifeboat, the Navy, and was there until 5920, and, made by Mr. W. J. Stephens, motor mechanic of the vessel. whendischarged,was appointedmotor mechanic of the first motor lifeboat of thenoteworthy as the first model he has made. Not only does this gentleman build the Lizard, the Frederick7.Pilley, in which heJudging from the photograph(Fig.2)itmodels, but also operates them as a feature served for fourteen years. appears areally expertattempt, and we ofexhibitions,givingridestoalland The latest boat, the Duke of York, hastrustitwill not be hislasteffort! Mr.sundry for the cause of the deserving charity. been at the station ten years in February,Stephens tells me it took him three months The model 74 -in. gauge tlin. scale 4-6-2 andMr.Stephens hasthereforespentto build, and he didit completely with aL.N.E.R. Pacific,tobe seenin the two twenty-four years as motor mechanic of thepocket penknife. accompanying illustrations (Figs. 3 and 4), Lizard lifeboats. In these days of war, when most of ourhas been on exhibition in various parts of the The Duke of York, whose picture you seethoughtsarewiththeForcesandthecountry, and Mr. Dove calls it his exhibition on this page (Fig.t), was built out of aMerchant Navy, don't let us forget that all" ace," for intwo yearsithas collected gift of £5,000 from King George's Fund foralong the coast of the British Isles there are -j:,8,000 for various war charities. Sailors, received between 1929 and1933.hundredsoflifeboatsandthousandsof He commenced tobuild this model in She is a motor lifeboat 'of the Watson type,men of the Royal National Lifeboat Insti-1931, and completed it in 1940.The frame 41ft. by sift. 8in.On service, with crewtutiOn quietly carrying on their gallant workis made from 3/16in. Bessemer steel, and it Of rescuing lives from the sea,Long mayis fitted with Wallschaerts valve gear.It is andgearaboard,sheweighsjustoverthey continue to do so. coal fired, with a working pressure of 901b. 15 tons. The seamless drawn -tube boiler is tested to She is divided into eight watertight corn-Powerful Model Locomotive 25o1b. to the square inch.The cylinders partments and fitted with 145 air cases, and her engine room isa watertight compart- Havingto make acallat Nottinghamare 21in. bore, akin. stroke, and thetotal ment.Her two 35 h.p.engines alsoare watertight,andwouldcontinuerunning even should the engine room be flooded. Her speed is just over eight knots, and she carries enough petrol to be able totravel 120 miles atfull speed without refuelling. Also she hasa line -throwing gun and an electric searchlight, and is lighted by elec- tricity. Since her arrival at the Lizard in 1934 she has been launched on service 19 times, and hasrescued70lives. Elevenofthose launches have been in service since the out- break of war, and they have resulted in the rescue of nine lives.She carries a crew of eight, and in rough weather can take up 'to fifty people aboard. Her motor mechanic, Mr. Stephens, whose personal hobbies are knittingjerseys, and the famous sport of bass -fishing with the rod, has made an excellent model of the Duke of York.

The Model Fig. 3.-The 71in. gauge Flying Scotsman locomotive built by Mr. Ernest Doveextreme left).. The model is tothe foot, and is . His son is in the driver's scat. 7

246 NEWNESPRACTICAL MECHANICS April, 1944 weight of the model in working order is I 'cwt. 8olb.Itisf tted wqh mechanical lubrication, and has gun-metal axle boxes 4 and Ross popsafetyvalves. Tho total number of bolts mid 'fly= used in con-

struction amount to 1,85o. Mr. Dove tells me that on a severe test last summer this locomotive was in steam for zo hours, carried 4,600 passengers, travelled a distance of 85 miles,and consumed' 285 gallons of water to a fuel consumption of 24 -Cwt. ofanthracitecoal-safetyvalves blowing off practically all the time.As soon asthe regulatorisopen the enginewill start away under the heaviest load without a sign of slip. Mr. Dove is in be seen on the extreme left of illustration (Fig. 3), and the young engine driver is his son. The illustration Fig. 4 was taken at the NottinghamMerchantNavyExhibition, where the proceeds totalled £450 forso weeks, and among thoseto be seen arc Nottingham's Lord Mayor - Alderman Braddock-and the Lady Mayoress, Sheriff Mitchell and his wife, the Merchant NavyFig. 4.-At Nottingham's Merchant Navy Week exhibition.Mr. Dove's models raised £250 Queen, and Commander Macness, chairmanduring the first six days.The Merchant Navy Queen and her attendants are present, also the of the Nottingham Branch of the MerchantLord Mayor of Nottingham (Alderman Braddock) and the"Mayoress, and Sheriff Mitchell and Navy Comforts Service. his wife.Mr. Dove and his son demonstrated the models. by injectors working at the rate of two pintshe has had no engineering . experience, he Other Locomotive Models a minute.) says he has been plodding along patiently Another of Mr. Dove's models isto be Mr. Dove has not yet made a thoroughat model engineering for the past 25 years, seenhere,the Southern Railway Schoolstest of the S. R. locomotive, but says sheand considers the hobby most interesting, class,which has taken him sixyears tois a very " sharp mover." He is now engagedand anoutstandingattraction. Healso build and complete, and follows closely thein completing a 7in.-gauge tank locomotive,stated that if any model engineering enthu- design of the Pacific engine as regards boiler,and also an L.M.S. Duchess of Buccleuchsiast would care to come and see his models water feed supply,etc. (The Scotsman'sclass, which he hopes will turn out as suc-at any time-and come to drive them-he water feed supply from tender to boileris cessfully as his previous efforts.Althoughwill be happy to oblige, if possible!

TRACING THE MISSING ELEMENTS(uranium) had been duly discovered, cata- Solutions to Probes logued and correctly indexed inthe great (Continued from page 243) Table of Elements which was originated in

and Problems andchemicallyimpracticablenameofPractical form by the genius of Dmitrii " Anglo-Helvenum." Mendeleeff, would it be possible for us to (See page 234) This, the latest claim to the discovery ofdiscover elements beyond uranium, which A Matrimonial Medley the missing halogen element, was made byis the heaviest of all the known elements, Jane's maiden name was Smith. two physicists working in the Radium Insti-and which forms the end ofthe known tuteatBerne,Switzerland,Mrs.Alice series of such bodies ? Is there, in short, Electing a President Leigh -Smith, a pupil of Mme. Curie andan Element No. 93, an Element No. 95, One of the candidates is unnamed ; we maythe wife ofaBritishdiplomat, and Dr.and even an Element No. loo to be dis- call him " X." The voting is then distributedWalter Minder, a Swiss professor, who iscovered ? as follows : Director of the Radium Institute at Berne. To such a question we cannot give any A B C E X The Leigh-Smith/Minder discovery an-definite answer.The probabilities areall nouncementfirst appeared inatentativeagainst there being any stable element of A X 5 0 o o higher atomic number than uraniuni (No. B 4 X o o form in July, 1940, the 1943 announcement C 0 X I 3 onlyhaving been madeafter" eighteen92), for, on theoretical grounds, it can be o 0 X 2 monthsof laboriousresearch."Whethershown, very decidedly, that any such ele- E Mrs. Leigh -Smith and Dr. Minder havement, under our own earthlyconditions, X o 0 I 4 X really hit upon the missing halogen elementwould be quite unstable, and that it would " I " who gave Bloggs all my votes cannotorwhether,liketheprevious Americanat once split up-or even violently explode be Clark or Everett, so thatI " must be" Alabamine," the proposed " Anglo-Helve--into far simpler and lighter elements. either Adams or " X." Since Clark gave thetium " is merely a chemical wish -fulfilment Itis, perhaps, poSsible that an element same number of votes to two candidates,itis, of course, quite impossibletosay,one degree higher than uranium may be he must have given one to Adams. since few, if any, of the essential details offound.This would be Element No. 93, to Experiment shows the above arrangementits discovery are yet available. which mysterious and entirely hypothetical to be the only possible one ;so that " I " To all intents and purposes, at least threematerial,the name eka-rhenium has been who gave all my votes to Bloggs must beelements arestillto be includedintheapplied.This element has been claimed to Adams. " missing "list. Masurium (Element No.have resulted in traces from the bombard- A Calendar Problem 43) is doubtful.The " Fifth Halogen " andment of uranium atoms with neutrons, but The first day of a new century can neverthe " Unknown Alkali Metal " still fail to givethe claim has never been substantiated.If, be a Sunday. The only possible days of thesatisfactory evidences of ;heir mass existence.therefore,eka-rheniumis,perchance,on week for that date are Monday, Wednesday, Even,however, supposing thatallthetheoretical grounds, 'a " possible " element, Friday and Saturday. elements from No. 1(hydrogen) to No. 92it is still very much a " missing " one. Who Stole the Sapphires ? Lop -Ear declares that he was with Slogger BOOKS FOR ENGINEERS Joe at the time of the robbery, Joe that he .has Gears and Gear Cutting, 61-, by post 6/6. DieselVehicles :Operation,Maintenance never been near the place, and Tommy the Workshop Calculations.Tables and For- and Repair, 5/-, by post 5/6. mulae, 8/-, by post 8/6. Watches :Adjustment and Repair, 6/, by Toff that he saw Lop -Ear in the vicinity. One post816. Engineers' Manual, 8/8, by post 9/, Plant Engineer's Pocket Book, 6/-, by oast of these statements must be untrue, and Practical Motorists' Encyclomedia, 10/0, by 8/6. hence one of these three is the criminal. post, 11/, Screw Thread Manual, 6/-, by post 6/6. Also, the Toff says that he heard of the Motor Car Principles and Practice, 6/-, by Mathematical Tables and' Formulx (Vest. post 6/6. Pocket Book), 3/8, by post 3/9. robbery from Bill Basher, while Grabstein Wire and Wire Gauges (Vest Pocket Book), Dictionary of Metals and Alloys, 10/6, by declares that Bill said he knew nothing about 3'8, by ;lost 3/9. post 11/-. it.Hence of one these three has lied. Published by Tommy the Toff, who appears in both lists, GEORGE iNIEWNES, LTD.,TOWER HOUSE, SOUTHAMPTON STREET, LONDON,W.C.2 _must therefore be t'ae culprit. April, 1944 NEWNES PRACTICAL MECHANICS 247 About Dead -Centres Details of an Experimental Gear for Cycles and Other Machines

ByG. W. HART greater efficiency of a twin -cylinder engine can be utilised, together withits reduced weight and cost. In practice a connecting rod is always used between the thrust force and the crank -pin, and thisto some extentgivesa forward thrustonthecrank,butitispurely incidentalandtheobjectofusinga connectingrod is notforthepur- a poseofovercomingthedefectinthe Fulcrum Ball -bearing Trouser leveragewhichhasbeenmentioned. A pulley on guard simple improvement on the present arrange- crank pin ment would be a connecting rod that moves directly parallel with the piston, and having Footrest -Position C. on its lower surface a cam so designed that of foot thereon determines the first motion of the piston would be to leverage (length of crank) drive the crank -pin forwards and then down- wards, but this can only be effective over 2 -_,peed the first quarter of the revolution.When derailleur gear '4 ),Light alloy t Lowest position tie crank -pin reaches 90 deg.this design or plastic of foot -rest would becomeinoperative,and,infact, during the second quarter of the revolution - Opening to insert Sufficieat-clecrah ce the difficulty would be greater than before. with this device pulley before fixing fulcrum ""..- There are, in fact, two motions required- one to push the crank -pin forward to a hori- zontalposition,and 'anotherto moveit Fig. i.-An improved driving gear for a cycle. backwards from 90 deg.to 18o deg., and thisisthe problem the solution of which WHEN the device known as the crankafter this getting smaller to the same degree.hasbeenattemptedintheinvention,a is used for the purpose of convert-This would be in order if the pressure ofdescription of which follows. ingareciprocalmotionintoa the piston varied in the same proportions,An ExperimentalCycle rotarymotionthequestionof" dead - but this is very unlikely.What is wanted, Gear centres " frequentlyarises,especiallywiththerefore, to overcome this so-called " dead - Interposed between the thrust force and regard to engines which includea pistoncentre" effect is some means whereby everythe crank -pinisalever whichispivoted in the design, and also where a lever motionprogressive degree of motion on the pistonon a line approximately 45 deg. to the line is used to turn a crank.The reference tois converted to an equally progressive degreeof thrust.This lever bears a cam so plotted " dead -centres in this connection is a looseof motion on the crank.If this is done, itthat, on the first movement, the crank -pin one and is not strictly correct:itis true,follows that the leverage will be constant isthrust forwards and downwards to the of course, that where there is an oscillatingthroughout the whole of the rotation of the90 deg.position, and then thrust down- motion there -must be a point where thecrank, instead of being in an increasing andwardsandbackwardstothex8odeg. motion ceases to move in one direction anddiminishing degree as at present. position.Both the face of the cam and the commences to move in another, and at this At the present time large fly -wheels arelength of thelever, with thepositionof moment there is no motion imparted to theusedinsingle -cylinderengines,andtheits pivot, is so plotted that for every degree crank, but this point of " dead -centre "is trend of I.C. and steam engines is to increaseof movement by the thrusting force there quite. negligible for practical purposes sincethe number of cylinders with the sole objectis a correspondingly, equal degree of move- it must consist of a period of time of quiteof getting an even torque ; but if the problemment of the crank -pin, so that the conversion immeasurable brevity, and it must occupyasstated can be solvedasindicated theof the reciprocal force is exactly converted a space on the crank -throw circle of quiteneedformulti -cylindersceases,and theintorotarymotionthroughout18odeg. immeasurable width.In other words, the line of the " dead -centres " isa knife edge FULCRUM and consequently, as already stated, is of no The position is vitally importance whateverinpractical machine ...---"Important in relation to design.What is commonly called a " dead - centre " is an entirely different matter. There direction of thrust is a dead space of about20deg. on each 9/4'4( of the two positions of the crank -throw circle which are normally regarded as arising from dead -centre," but these cannot arise from this fact of physics, and itis a matter of DRIVE STARTS leverage only.From o deg. to to deg. the HERE motion of the piston. (as representing any SPACING OF POSITIONS reciprocating force) moves verylittle,but OF CRANK. PIN it does in fact move.It must move, because pOint to deg. is in a different position rela- FROM 1-9 ARE EQUAL tive to the piston to point o deg.Pressure SO ARE CORRESPONDING required upon the piston to rotate the crank POSITIONS OF LEVER is very great from o deg. to to deg., but if -/ great enough it will always move the crank, unless it should so happen that the points piston, crank -pin, crank -shaftare dead in THEREFORE: LEVERAGE line, whichisnearly an impossibility on IS CONSTANT THROUGH account of the lack of width in this line WO° AND RECIPROCAL (speaking in popular terms). MOTION IS PERFECTLY CONVERTED INTO Crank Leverage ROTARY MOT/ON The leverage upon the crank at different DRIVE ENDS positions of the crank -pin varies froth o deg. to 90 deg., getting progressively larger and a.-Diagrain illustrating the theoretical principle. 248 NEWNES PRACTICAL MECHANICS April, 1944 motion of the crank -pin.If two such leversacceptable to the user of an invalid carriage,have no conception of this, nor have they are used in conjunction with two thrustingwhere propulsion is obtained by the use oftheinclinationtolearn ;thisinvention forces, it will be seen that a perfectly equaltwo levers,asthe improved transmissionshould also be of useto them since the torque of 36o deg. can be obtained withwould enable him tousea much higherdancing motion of the butcher's boy, which the use of two pistons only.These facts gear,and, bya -simplearrangement, theis so popular, would become fully effective arc shown diagrammatically in Fig. 2, whichfulcrum of the levers could be adjusted soinsteadofa pure waste of energy asat shows one lever only.Although the termthat the " gear " could be raised or lowered piston has been used freely in the foregoing atwill. 'Therearealsoabout500,000 present.Further applications in this con- remarks, the present invention has in mindcyclists .who reach some degree of successnection, such as the treadle sewing machine the employment of any rectilinear motionin rotating pedals through 180 deg. by whatand the foot lathe, could be quoted, and its such as in machines where lever or treadletheycall" ankling,"but there areaboutapplication to the single -cylinder gas engine operation is used.It would be particularly8,000,000 cyclists in this country -alone whois fairly obvious. Letters from Readers A PENDULUM HARMONOGRAPH SIR,-I was interested in the " Harmono- graph " described inthe November, 1943, issue of PRACTICAL MECHANICS. I made a similar instrument about sixty yearsago,andencloseafewspecimen -designs which were produced with it. The pen I made from a piece of 4in. glass tube (see sketch), drawn out to a point, and this was ground down on an oilstone till the opening was large enough forthe ink to flow. My ink was methylated spirit stained with analine dye, and a little glycerine added to make it a little more stable. A. R. HALLETT (Sturminster Newton).

Specimen designs produced on A. R. Hallett's harnzonograph.

CUTTING SCREW THREADS these was hisstatement that the escape SIR,-The following tip may be of interestVelocity from the earth's attractionis 6oq toownersofsmallscrew -cutting miles per second, when the correct figure lathes. is 6.95 milespersecond. Quitean I needed to cut a screw thread of 26 toappreciable difference when space travelis theinch-a commonfigureinbicycle contemplated. This valueisobtained as engineering;-but had no gearwheel over 55 follows: teeth nor any multiple of 13 below that. The value of the gravitational attraction Being unable to obtain a 65 wheel I deter -varies as the square of the distance and for Tinned to use sprockm-wheels connected by R2 a roller chain." Magneto cogs " are pro-any height S it is given by g, = G. curable having eight teeth upwards ; bicycleand when (R S) is made equal to r, then flub -cogs from 12to28 teeth,screwed internally to fit a standard boss ; and chain -theequationofmotionofaprojectile Wheels from 28 to 5i teeth,all tofit the projectedvertically upwards willbecome, standard Zin. by lin.bicycle roller chain. dv R2 and if both sides are multi- My lead -screw has eight threads per inch,dt--- - Class rube before breaking a grinding So I procured an eight -tooth magneto cog plied by dr,v.dv = - G.R2. r2.dr andif to form Pen and turn xiitout tofitto the headstock thisis integrated between the limits when main spindle, or alternatively,toagear- r = R (the radius of the earth) and r = r (the height of the projectile), then, Details of rocking table and method of making pen Nryheel engaging with another fixed to that spindle, to give left-hand thread.Ifitted VR -GR 2 r I \ In thelimit an old bicycle freewheel-boSs to the lead: 2 R ri ;Frew shaft,so that any hub -cog can bewhen V, becomes zero, then the distance r fitted at will ; and some calculation is saved, is Since withthisarrangelinerir,the number infinite and the initialvelocity will be of threads per inch will be the same as the given by :velocity of liberation = 1/2.G7R. number of teeth on the driven sprocketwhen G isthe Value of the gravitational Wheel-in this case26. The chainis attraction at the surface of the earth arid R tensioned by an idle sprocket whose life is isthe radius of the earth. immaterial,turningonanintermediate The second point is that Prof. Hermann iearwheel-shaft whose position is, of csoiirle,Obeith was hot killed by rocket 'e'xperiments, adjustable. W. H. SPOOR (Saltash). and as far as is known, he is still alive to -day. Ma.'; Valier was killed by the explosion of SPACE ROCKETS liquid fuel rocket car, but Herr Tilling was SIR,-Your correspondent, Mr. Scanlon, aCtliallykilled by the explosion -of about gave some interesting details regard-3olb. of powder in his workshop. ing space rockets but two grave efrori Weft E. BURGESS, President. Method of pivoting the pen -holder included in his information.The first of Combined British Astronautical Societies. -V

April, 1944 NEWNES PRACTICAL MECHANICS 249

. (e)Electrolysethissolution.usingcarbon desired, could then be redissolved in aqua regia to form electrodes. a pure solution of gold chloride. This method fails when dealing with gold alloys You must always bear in mind the fact that the and, in any case, appears rather lengthy, givingextraction of any one metal from its alloys is a process black deposits instead of white crystals of thewhich must necessarily be governed in its details by a QUER1EScil4 metal.-S. G. Bubb (Porthcawl). consideration of the other ingredients ofthe alloy. UNLESS we are informed of the precise, or, at least, For this reason alone,itisquite impossible to lay the approximate nature and composition of thedown hard andfast -rulesorproceduresforthe alloy from which you wish to extract silver ancl'or gold extraction of silver and gold from all their different it is absolutely impossible for us to advise you as toalloys, mixtures and compobnds. ENQUIRIES the exact mode of procedure for extraction of the required metals. For one thing, not all metals are soluble in diluteExtracting Oil from Hair A stamped addressedenvelope,threepenny nitric acid, and silver itself, when alloyed with some TAM interested in an experiment in regard to stamps, and the query 'coupon from the current of these metals becomes very difficultly soluble in this extracting oil from hair.I am anxious to issue, which appears on back cover must be enclosed acid.Provided that the silver in the alloy is in such a retain all the qualities of the oil.Can you tell with every letter containing a query. Every form thatit can be dissolved out with nitric acid,me the best way to achieve this ? query and drawing which issent must bear the your proposed scheme of extraction is quite feasible, Since horsehair is the kind most easily obtained, name and address ofthe, reader. Send your but it would be better if you collected your silverI would most probably make an attempt with queries to the Editor, PRACTICAL MECHANICS, chloride, suspended it in water and passed hydrogenthat variety first, using the tail or mane as likely Geo. Newnes, Ltd., Tower House, Southampton gas into the aqueous suspension.This would resultto give the greatest yield of oil.-J. A. V. Connell Street, Strand, London, W.C.2. in the silver chloride being converted into metallic(Southport). silver, which would fall to the bottom of the vessel asWE believe that various attempts have been made to a black deposit. This could then be filtered off, washed, extract a usable oil from waste hair, but they Gesso Powder dried and fused tinder a layer of carbon and soda.have not been successful in practice on account of CAN you oblige by giving me the receipe for the very small amount of oil which the average hair -,making gesso powder ?This usedto be Large Retort Stand contains. obtainable before the war, and was used for However, if you wish to make experiments, your the fancy relief moulding on the edges of lamp best planistofit up the apparatus shown in the shades, etc., when mixed to the desired consistency accompanying rough sketch.The hair is placed in a withwater. Ibelieve some peoplecallit flask together with the solvent, the quantity of the " barbola," which is obtainable in paste form, but Water Exit latter being immaterial.The solvent is then boiled isnot suitablefor my purpose.-J. Osbourn for an hour or two under the Liebig's condenser. (Leicester). Lrebig'sCondenser After this, the solvent isfiltered and then carefully distilled off, leaving the extracted oil behind. THE reason why gesso powder is so hard ,to obtain Solvents to use are many and various.You can try A nowadays is on account of the fact that the gold benzene, ether, light petrol (petroleum ether), alcohol powder which is incorporated into it isonly being (rectified spirit), trichlorethylene, carbon tetrachloride, supplied for essential purposes. chloroform,naphtha,carbondisulphide,ethylene Essentially,thismaterialconsists of about equal Clamp dichloride, and many more. Although etheris an parts of pigment, whiting and a binding material such excellentsolventforoilsandfats,itsuseisnot as dextrin.This mixture is made into a paste with unattended with some danger, for ether has been known water. The product can be much improved by to detonate violently when boiled and distilled, causing incorporating alittlecasein glue powder intoitin Warer Entrance order to stiffen and harden it. damage and injury to the operator.Our advice to you A still better gesso can be made up on an oil basis, isto keep clear of this particular solvent, unless, of as below : course, you happen to be skilled in its use. (a)Fish glue (liquid) The chemical apparatus described can be obtained 4 parts from any firm of chemical wholesale suppliers and Water .. r part laboratory furnishers, as, for example, Messrs. J. W. (b) Raw linseed oil r part Towers, Victoria House, Widnes. Clear oil varnish .. tpart Whiting 6 parts Work intob " sufficient gold or other pigment to Converting a Universal Motor shade.Then work " a " into " b." Glass F/ask TRECENTLY purchased a .1 h.p. electric motor This material is slower drying than the water gesso, Containing of the universal type.I would like, if possible, but it is stronger and much less liable to flake or chip. Solvent and Hair to convert this to a repulsion type motor for Its drying speed may be increased by adding a little 230 volt 50 cycle to run at 1,450 r.p.m. The bore of paint " drier " to it. statoris 3in. and the 2 -pole rotor is 21.111 tin. diameter and 2in. long.There are 18 slots and Battery Plates and Electrolyte 36 segments to the commutator.Would it be necessary to rewindthe twofieldcoils,also T HAVE five negative and four positive " Nife " would it develop enough power to drive a 31in. A battery plates (new), and I want to use them for lighting a 6 -volt, 24 -watt lamp. Can this be Tripod bench lathe ?-Charles Harris (Tunbridge Wells). done,' and, also, what sort of case should I. use TT does not appear that there would beanygain in for the plates, and what kind of electrolyte should 1- converting the machine into a repulsion motor, as I use ?Could you tell me the capacity of the itis hardly likely it could be converted without loss plates ?Their size is 41in.din. and their width of efficiency, and the converted motor would have is for the positives and'-!/ioin.for the similar characteristics to the former machine-that is, negatives.-J. W. Smith (Sandown, I. of W.). the speed would vary with the load.The repulsion - Bunsen Burner or Spirit Lamp starting -induction motor starts up as a repulsion motor HE capacity. of one positive and one negative plate (or other heat source) but at -a certain critical speed a centrifugal device short T- willprobably be about z8 ampere hour, witha circuits the, commutator, and Usually then raises the normal discharge rate of about 3.6 amps.Each cell Simple apparatus for extracting oil from hair brushes from the commutator to reduce Wear on these would give an average discharge voltageof about by means of a boiling solvent. parts.Such a machine runs at a fairly constant speed 1.2 volts. on varying load but it would be a difficult matter to You would, therefore,requirefivecellsfor theAlternatively, the precipitated silver could be dissolvedfit such a short-circuiting device to a series motor. 6 -volt bulb, and a discharge rate of 4 amps.It willin 'dilute nitric acid, and thus converted into silverIt is probable that the J h.p. motor would drive the be seen that you could not build up a battery to light a nitrate. lathe in question. 6 -volt lamp, even by using only one positive and one With regard to gold, there is no single acid (except negative plate per cell.The electrolyte used in such selenic acid) which is capable of dissolving gold. Your cells is art aqueous solution of caustic potash having aplan,. therefore, would be to dissolve out the variousMaking Dolls : Papier-mâché specific gravity of 1.200. other ingredients of the alloy with dilute or concentratedWOULD you please oblige me by answering the mineral acids, and then to boil up the residue with following questions ? Electric Soldering Iron aqua regia,whichlatterisa mixture of 2parts T.I wish to make fabricated dolls of pre-war TWISH to make a al -volt soldering iron for useconcentrated hydrochloric acid and r part concentratedstyle, and would be glad to know the names of outdoors, as my blowlamp does not appearnitric acid.A yellow solution of gold chloride wouldthe necessary materials. tobevery satisfactory.I can obtain the supplythus result. This should then be filtered and evaporated 2. Ihave made papier-mache articles,but from two 6 -volt 125 amp. hr. batteries. Can youdown to dryness,the resulting crystals being thenowing to the waste of time in etching and drying inform me what length and gauge wire I should strongly heated ina porcelain crucible in order toof same, I would be thankful if you could tell need for the element, or if I can buy the elementconvert them intometallicgold, which latter; ifme the compositions of something similar to already wound ?Also, how can Ifititinside the copper bit ?-F. S. Horsman (Swindon). iiiintulmilliniiimiliffilliminirminiumillummillimiminiiiirminiflininiiiimilimmillimmenninniminumummininanninilimiiiiiffir, FOR arib.soldering iron you require aheating -a- element of about 90 watts rating, that isto take THE P.M. LIST OF BLUEPRINTS 7.5 amps at 12 volts. We suggest that you use if yards a . -.7t. of 18 s.w.g. nickel -chrome resistance wire. You could 7.-- The " PRACTICAL MECHANICS " £20 CAR The P.M. " PETREL " MODEL MONOPLANE wind the element on a mica tube or strip wrapped = (Designed by F.J.CAMM), E.--- round the supporting tube to which the handle is 1--: Complete set, Ss. = attached, covering the element with another thin tube Ws. 6d. per set of four sheets. or strip of mica ; The I-c.c.TWO-STROKE PETROL ENGINE* g... the whole being arranged tofit '----: " PRACTICAL MECHANICS" MASTER Complete set, Ss. 7.:-.. snugly inside a hole bored in the copper bit. = BATTERY CLOCK* .... Blueprints (2 sheets), 2s. STREAMLINED WAKEFIELD* Extracting Silver and Gold from Alloys = MONOPLANE -2s. The " PRACTICAL MECHANICS" OUT. WOULD you kindly advise me of a method for BOARD SPEEDBOAT LIGHTWEIGHT DURATION MODEL ,== extracting almost puresilver andgold Full-size blueprint, 2s. from alloys of these metals. 5 7s. 6d. per setof three sheets. = A method I could suggest for silver wouldbe: Ei P.M. TRAILER CARAVAN* = E-,.-- A MODEL AUTOGIRO* = (a) Convert the silver alloy to nitrates of the 7,..- Full-size blueprint,Is. Complete set,10s. 6d. .7.-.. metals contained in the alloy by the action T-4 Theabove blueprints are obtainable, post free, H of dilute nitric acid. SUPER -DURATION BIPLANE* from Messrs. G. Newnes, Ltd., Tower House, .e (b)Deposit silver chloride from the solution=__.=. with a chloride of, say, sodium. = Full-size blueprint, Is. i Strand, W.C.2. = (c) Wash the deposit and filter. = M denotesthatconstructionaldetailsareavailable,free, withthe blueprint. (d) Dissolve the contents of the filter paper it) ..-,ilAt...10,1, k.,. . - 'Al - - ammonia solution, I..-T-.."--: 250 NEWNES PRACTICAL MECHANICS April, 1944 papier-mâché work.I don't want to use Delphhints or recommend some books on the subject. One 3 pint jar with a 3 pint porous pot. or china.-M. McKennan (Southfields). I understand the supply reaches the carbons Two 2 pint jars with a 3 pint porous pot in each. through aresistance(thisresistance varying One 2 pint jar with an old porous pot (2 pint size). The making of serviceable dollsis not an easywith the diameter of the carbons), the carbons Four cells -6 volts. task.It demands much skill and experience, to say nothing of equipment.The bodies of most dollsbeing mounted to adjust the air gap.Is above The 3 pint size may be all right, but I'm afraid are composed of a hempen fabric which is frequently right ?The supply is 220-230 V. A.C. Wherethe 2 pint jars with 3 pint porous pots are not; painted a flesh colour.This materialis sewed upcould carbons be obtained, and are sun -ray lampsthere isn't, of course, the amount of solution or andisusuallystuffed with sawdust and/or otherstill purchasable under a medicalcertificate, clearance. Am I at fault here ? fibrous materials.The limbs, if they are not of potor otherwise ?-J. Lowry (Belfast). Also the last cell with the old pot : do porous or of composition, are usually made separately and then pots deteriorate ?I have Brunswick blacked and sewn on to the main trunk.The head (and limbs) are A N ordinary arc between carbon electrodes will giveVaselined them. usually moulded in porcelain, celluloid or other material A A off ultra -violet rayssuitable for your purpose, I am in earnest to get my clock correct, although and afterwards painted.The eyes may be painted in and could be used with a first exposure of about five72 yearsold. Electrically I'm not very well or, as in the better -class dolls, they may be attachedminutes.You may be able to obtain carbon rods forup, only by thinking things out. Do you think I separately.The hair is usually a bleached and dyed this purpose from the Morgan Crucible Co., Ltd., ofdo well-or not? I now get to lifts of crutch arm animal hair. Battersea Works, London, S .W.11. per contact, 20 left and right swings of pendulum, It is possible to mould a doll's head in ordinary More powerful radiation, however,is given from10--to----2o.It's all home made, but well made; plaster, but /he result is never satisfactory owing toah arc drawn between tungsten electrodes, with whichbob weighs t2lb. approximately.I have fitted the essential fragility of the plaster.Most of the dolls' about two minutes' exposure should be sufficient formy trailer finger inside pendulum rod, thus heads and limbs of pre-war years came from Germanythe first time.British Thomson -Houston Co., Ltd.,of getting a directly central movement, also my and Japan, but itislikely that in post-war times aRugby, manufacture such tungsten electrodes.In theback stop I have carried to top, with a reversal similar industry will be set up in this country basedFinsen lamp the light is transmitted through a systemof the arm pin, doing away with that pushing on the use of one or other of the new synthetic moulding of water-cooled quartz lenses which concentrate themovement, giving the gravity arm less to do. products. light and permit contact treatment of a patient withoutPlease say if 20 swings of pendulum is good or If you inquire at Messrs. W. and G. Foyle, Ltd.,danger of heat burns. With a straight arc between annot good enough. I am anxious to know-C. Ward upper carbon electrode 13 m.m. diameter and a lower (Spondon). Charing Cross Road, W.C.z, you may be able to obtain carbon r2 m.m. diameter, you requite an arc voltage a book on doll -making, although our lists do not revealof 3o to 35 with a current of 20 to 25 amps.The bestWE are very interested in your letter, and you have any such publication. and most economical method of operating such an arc certainly made a good job of theclock, and Sources of supply for various doll -making materialsfrom A.C. mains is by the use of a step down trans- although it is possible to get much more than to lifts are as under : former with a secondary voltage of about 6o, but youper impulse, thisis only obtained by patience and HAIR.-Messrs. Morris Charkham, Ltd., York Road,could use a resistance, m' circuit with the arc directcritical adjustments of all parts.If you are interested Battersea, S.W.I x ;Nagele's (London), Ltd., Edwardfrom the mains. In this case you would need a resistancein obtaining longer swings (which do not affect time- Street, \.x. of about 8 ohms, for which you could use 64 yds. ofkeeping but merely saves battery current) you should DOLLS' CLoninin.-DolgarManufacturingCo., to s.w.g. nickel chrome resistance wire. pack the lower magnets up gradually, so reducing the Ltd.,56-7, Lower High Street, Stourbridge, Worcs.; It is rather doubtful if you could obtain a new sun -ray clearancebetweenpole -piecesandarmature,and Messrs. F. J. Prudoe, 13oz,,- City Road, Islington, N. arc lamp at the moment, but you may be able to buy a adjust the trigger height and contact strip.This is DOLL MANUFACTURERS, COMPONENTS, ETC.-Messrs. second-hand one.Perhaps your local doctor or clinicadmittedly a tedious process, and in the end little is Bradfield, Ibberson and Co., Ltd., 78, Norfolk Street, could assist you. actually saved, as the batteries deteriorate even when King's Lynn, Norfolk ;Messrs.J. K. Farnell and not actually delivering current.It Co., Ltd., Alpha Works, Acton Hill, W.3 ;Messrs. is interesting, however, and gives Merrythought,Ltd.,MerrythoughtWorks,Iron a feeling of satisfaction when im- Bridge, Salop. provements are made. 2. A good substitute for papier-mache is : The large porous pots inthe Finely shredded paper, too parts. small jars will not affect things at Zinc oxide, 75 parts. all. They will still not deliver The above is mixed to a thick paste with a fairly strong Escaping Hydrogen any more current, as the cell will solution of celluloid in a mixture of equal parts of Gas Bulb Tube only deliver 1.5 volts no matter acetone and amyl acetate, or, alternatively, the above how big the individual parts. A may be made into a paste with shellac varnish (" button certain amount of " corrosion " polish "). isalwaysobtained with these cells, and is merely slight chemical Electrical Heater Elements iron Oxide Chloride action, plusa ,deposit ofthe orOxalate salammoniac due to evaporation. 11%1 connection with some experiments whiCh are Zinc and Always" top up " with plain A being carried out to ignite " producer gas " water, not salammoniac solution. on starting up lorries driven by gas generators, Hydrochloric Acid A drop or two of oil on top of the it has been found that se small coil of (So per cent. (Dilate) solutionwillhelptoprevent Ni, 20 per cept. Cr.) wire heated from 6 -volt creeping, and externally the jars supply is quite satisfactory except for one thing. should be keptquite cleanto Using a spring push-button to close the circuit avoid leakage of current and loss for about three seconds only, is quite effective for Method of snaking pyrophoric powder. of power. Porous pots do about ao starts, after which the Ni-Ch. wire deteriorate, and after a period of becomes burnt through at about the middle turns use need replacing.The zincs also need replacing of the coil. Pyrophoric Iron Powder but ifthe solution is too strong, they will naturally Is there a wire which will not oxydise so soon,WILL you help me with the following query ?be eaten away quicker.It would appear from your such as tungsten -carbide drawnwire?If so, I desire to know how I can make iron withdetails that your solution is rather too strong. where can it be obtained ?-G. H. Child (Hove). pyrophoric properties (becoming red hot on being shaken). After cooling down has a change taken THE cost of a tungsten -carbide drawn wire wouldbe place ; prohibitive, anditisdoubtfulifyou would if so, what change, and can it becomeRestoring Daguerreotypes procureitwithoutgreatdifficultyunderpresent hot again if shaken ?-A. Richmond (London, F..). conditions. IN order to make pyrophoric iron powder, take ironT HAVE in my possession an old daguerreotype Thereisahigh -temperatureresistancematerial oxide, iron chloride or iron oxalate and heat any, of (the old photographic process in which the known as Kanthal which, might meet your needs, andthese in a stream of hydrogen gas at a temperature ofprint is on metal). Owing to its extreme age, it we suggest you plaee your problem before Messrs. about 400 deg. C., i.e., below dull red heat. The ironis rather faint, and I wish to preserve it. Henry Wiggin and to., Ltd., Birmingham. compound will gradually turn black. This black Will you please tell me the best way to store substance is metallic iron in a condition of very fine it, i.e., should it be kept in darkness or daylight'? powder.When scattered into the air, it becomes in-Also, can yciu inform me of any safe way of Converter Details candescent and fallsto the ground in a shower ofimproving it ?-L. G. Chamberlain (Woodford). T HAVE a ixo-volt series wound D.C. motor ofsparks. The apparatus necessary for this experiment isTHE restoration of daguerreoytpes is 'atask for the approximately'loth h.p. and I want to make shown in the accompanying sketch. expert only, and if you have not had any experi- a converter from D.C. to A.C. and rectify this It is essential to observe that the iron salt in the bulbenceinphotographic manipulation we would not for the power supply of a receiver, as I find thattube is not heated to visible redness, otherwise theadvise you to undertake such a task.Essentially, the x xo volts are not quite sufficient to run a large iron powder obtained will not be pyrophoric. restoration processisa simple one.It consists of superhet.I wondered if it would be possible to It is still easier to make pyrophoric lead. Add to aimmersing the daguerreotype in ator 2 per cent. wind on other coils under the field coils to obtain solution of either lead nitrate or lead acetate an equalsolution of potassium cyanide in distilled water.The a higher voltage. I have tried to make vibratoryquantity of a solution of tartaric acid.White leaddish containing thesolutionisgently rocked, the converters but cannot find a suitable rectifyingtartrate is precipitated. This should be filtered off andresult being that the weak cyanide solution gradually valve.-A. J. F. Trott (Kintbury). dried. When this is gently heated in a test tube it turnsdissolves away the film of tarnish, leaving the daguer- black owing to the production of pyrophoric lead. Thisreotype image clear and bright.The greatest care pRESUMABLY it is your intention to use the serieslatter gives rise to a shower of sparks when scattered A motor as a dynamo and drive this with an A.G. must be taken not to overdo the cyanide treatment, motor. A series wound dynamo gives a voltage which into the air. for after the tarnish has been removed, the cyanide varies considerably with the load current and would In the case of these 'pyrophoric powders, the effectsolution will attack the image on the daguerreotype hardly be suitable for your purpose.The simplest is due to the rapid oxidation of the metal,i.e., theplate and will gradually dissolveitaway. Hence, method would be to rewind the field coils with a shunt combinationof thefinely dividedmetal with theImmediately the tarnish has been removed, the daguer- winding which can be connected in series with aoxygen of the air to form the oxide of the metal. Thereotype plateis immersed in clean,distilled water regulating resistance and fed from the brushes. Whenchange is not reversible and the metal will only become and rinsed in several changes of distilled water in running on full load the present field current will be incandescent once. Moreover, the metal must beorder to remove all traces of the cyanide.Distilled about I amp., so that the present number of amp. turnsfreshly prepared for this effect to take place. water must be used, and the daguerreotype plate must will be practically the same as the number of turns. be dried quickly in a current of cool, dust -free air, To obtain the same amp. turns with a shunt field" P.M." Battery Clock otherwise streaks and markings may appear on the winding carrying i/16th arnp. you would need to use WITH reference to the cells for the P.M. battery plate. a winding having t6 times as many turns as at -present clock, I am having trouble with crystallising There is no way of renovatingadaguerreotype and wire having I/ 16th the cross sectional area of theon the porous pots, and the ± zinc rods are other than the above, and it you think anything of the present wire.The voltage of the machine can best benearly eaten away, after only three months' use. daguerreotype in question, we should very strongly increased by driving it at a speed somewhat higher than HaveIgot thesalammoniacsolution tooadvise you against tacklingitsrestoration yourself: the present full load speed.Some increase of voltagestrong ?Then again, I have various sorts ofUnfortunately, there are very few people who have had could also be obtained by using a shunt field windingcell sizes, as follows : any experience in the restoration of daguerreotypes. in which the size of wire is reduced in a less proportion The only firm we know which has had experience of than the number of turns is increased, compared with New Edition such jobs is that of Messrs. James. A. Sinclair & Co., the present series winding. Ltd., 3, Whitehall, London, S.W.I. NEWNES ENGINEER'S Apart from having thedaguerreotype restored in the correct manner, the only thing you can do is to Carbon -arc Sun -ray Lamp VEST-POCKET BOOK re -bind it to its cover -glass in order to keep, impure IHAVE been interested for some time in the By F. J. CAMM 10/6 or by post II/ - air and fumes out of contact with the metal plate.It making of a carbon arc sun -ray lamp and Obtainable fromallbooksellers, or bypost from would be advisable for you to keep your daguerreotype having onlyveryelementary knowledge of the George Newnes, Ltd. (Book Dept.1, Tower House, in darkness, and away from damp and impure atmo- subject,I shall be glad if you can give me some Southampton Street. London. W.C.2. spheres. April, 1944 NEWNES PRACTICAL MECHANICS 25

ENGINEERS, DRAUGHTSMEN AND --.=---,ELECTRADIX-, MATHEMATICIANS NEED A PELMAN DYNAMOS -MOTORS - ROTARIES. THE For essential and experimentalwork, permit free.Fine modern quarter -horse D.C. motors, 200 to 250 volts, enclosed, TRAINED MIND drip -proof silent bearings, flange or base fixing, double end shaft,Be.dia.,1,450 WHY, amongst the brainiest and revs. ;size 71in. x 7in., weight 35lbs. most successful men and Compound. We fully guarantee.II5th women in England to -day,are M.P. 831101, H.P. £4.Larger powers ROTARY CONVERSION TABLE in stock. there so many Pelmanists ? Themost compact, handy and Why does being a Pelmanist CRYSTAL SETS. Gambrell WIN type accurate table ever devised. . . . with selector switch,tuning condensers Converting inches to millimeters - lift you right out of the rut ? and permanent crystal detector, in closed millimeters to inches -to an accuracy The answer to these and to many portable case, 551-. Victory Pocket Type of 7 decimal placesisa matter of crystalreceiverin bakelitebox.35I-. seconds with the new " Con- other questions relative to Your TheWall Nut. A superior set for table fractor." Thereadings,ranging Success and its assurance through or wall, new model in polished hardwood from "general purpose " to "extra Pelmanismwillbefoundin case, tapped A.T.I. and variable condenser accurate," are clear and foolproof - Success." tuning,421-. Aerial Wire, 7122bare thetablewashableandvirtually " TheScienceof In copper, 51- per 100ft.Lead-in wire, 4d. indestructible. Forfullerdetailswrite this book you will read accounts per yard.Aerial Insulators, 2d. each. toW. J. Steele & Co., Ltd., 641,Staines Rd., Bedtent, Mdx. by Pelmanists themselves of how CHUCK JAWS (new). 100 setsof OBTAINABLE FROM ALL W. H. SMITH & SON'S SHOPS wholeliveshave been changed 3 -jawself -centring Scroll. Twosize* for the better by Pelmanism. Sin.jaws, 81-setofthree :4in.jaws, 101- set of three. What Pelmanism Does CIRCUIT BREAKERS, ironclad ; 2- and SCENIC RLY. MDG. Pelmanism brings out the mind's 3 -pole withthermaldelay,351-. Mains Builda realistic 'iettingaroundyear Contactors. 351-.Auto -cutouts in stock. miniature Railway.The popular " 00 " latent powers and develops them to scalepermits an extensive layout. A the highest point of efficiency. RECORDER PARTS.Spare parts, new. new Planbook has been written Chart Drum andClips,516. Magnetic by anexpertbuilderandoperator. It eliminates such defects as :- Clutch, 6 volts,complete, 251-.. 9in. Price516,by post 5/9. (Below) Traverse Shaft, 4in. threaded 120 to inch Depression Pessimism with bearings, 1216.Stylus, with carriage Forgetfulness Timidity rods and brackets, 716.5 -pin plugs, with PLY. PLANSPlans"e8ide" for " 00 " Shyness Procrastination panel socket and cords, midget type, 416 pair, Rlys.givenecessaryinstructionsfor Architl. and Eng. features conforming to Indefiniteness Indecision WATER TANKS forengine's,storage. B.M.R.S.B.standardsand" Dubin," Morbid Unnecessary etc., kW.Stuart galvo. iron 5ft. high, " Trix," etc. (Below) Thoughts Fears I4in.dia.,withpipeunions,only401-. Smalloilor sudstanks,square,plate, which interfere with the effective 64in. x Sin. x lin.,116, post 6d. MINIATURE AIRCRAFT working power of the mind, and METAL CABINETS AND COVERS. R. H.Warring reveals art of making it develops such valuable qualities Die cast aluminium boxes with hinged lid ; models which bear closest scrutiny and look as :- inside Biin. x 4/in. x 51 -in. for oscillators, " real " to camera eye.Nearly 60 illus. etc., 10/-.Covers.Light metal, ventilated withplansforrepresentativeinoderu -Optimism -Confidence special arch shape to contain 61in. x 5in., aircraft. Price4/6,by post4/8. Also -Perception -Self-Control with terminal cover extension, 316. " ThreeRapid Methods ofMaking the Identification Models." Price 1/6, by post Add -Judgment -Ambition 1;8. (Below) FINISHING -Courage -Initiative FOR OTHER BARGAINS SEE PREVIOUS -Will-Power -Reliability ISSUES. SHIPS AND 'PLANES 'Planes 1/72. Ships 50 ft. to 1 in. Over 70 T Ocoil Half fees for serving members of Please enclose postageon mail orders. Plans released -6d. tot', (Below) His Majesty's Forces (Apply for Services Enrolment Form) ELECTRADIX RADIOS, GALLEONS ,"Planbook," "Building a . . . . toyourmodelswith Your Unsuspected Self 214 QueenstownRoad, Galleon." Full instns.forbuilding fine Battersea, London, S.W.8 modelsofthesegrand old ships. Plasticine,' the famous modelling Pelmanism teaches -you to rely on Profusely illustrated. Set of 8 progressmedium. Fornearlyhalfa yourself.Every man and every Telephone ;Macaulay 2159 plans for " Golden Hind," size 20 in. xcentury Plasticine 'hasbeen woman has within himself and her- 30 in. Price 12/8, by post13/-. (Below) used by modelling enthusiasts the self a mine of abilities that lie dor- PARCEL OF How to build a fast racing world over, and to them at least, mant, ready to be brought into YACHTmodelby newrapid this material of 101 uses is indis- service through the proper training method at cosh of few shillings.Working USEFUL APPARATUS drawings, plans and licence to use patentpensable. Suppliesarestrictly of the mind.This is the time to (appd. for). Price 3/6, by post 3/8. (Below)rationed so make your ' Plasticine ' bring them forth and to use them Post7/6paid last. for the benefit of yourself, your Send also Working model dependants and your associates. stamped Id. OIL ENGINE(runsonair). addressed Made of simple materials and tools. New Remember -Everything you do is envelope for techniquefullyillustratedinbook. preceded by your attitude of mind. latest Price 2/-, by post 2/2. Listof other HA RBU T T The Pelman Course is taught by ?equipment. Send 3d. and undamped addressed envelope correspondence only. There are no (England,for nets (early April) list of over 100 Plans classes to attend. The.problems of Scotland and and " Planbooks." MODELCRAFT LTD., Wales only.) 77(P.M.),GrosvenorRoad,London, `Plasticine eachPelmanistareconsidered AlsoBooklet, S.W.1. separately by highly trained, sym- "Experiments in Chemistry." pathetic instructors.Under this 6d. plus post- understanding system, even the - age Id. most timidstudentgainsself- BECK(Scientific Dept. A), 60, High St., Stoke Newirwron. London. N.16. YOU confidence immediately. The Pelman Courseisfully describedin" TileScienceof flaw may fre litotteg can become a first-class Success."The Course is simple it,the idea _Oen't AfIceive it! and interesting and takes up very LET RADIO ENGINEER little time ;you can enrol on the most convenient terms. The book Post coupon now for free booklet and learn will be sent you, gratis and post how you can qualify for well -paid employ- free, on application to :- ment or profitable spare -time work. Pelman Institute We arespecialists mwmismoimmilowwimiimLTD in Home -Study T. & C. RADIO COLLEGE, (Established over40years.) market, on a Royalty basis, CoursesinRadio Reception, Servic- 2, The Mall, Ealing, W.5 130 Albion House, New Oxford St., any of your ing, Transmission, London, W.C.1 Television, Mathe- Please send me free details of your Home -Study MECHANICAL AND matics and Radio Conrses in Mathematics and Radio. PE L.11 A N (OVERSEAS) INSTITUTES: ELECTRICAL DEVICES Calculations. - "r - NEW YORK, 271, North Avenue, New Name Rochelle. MELBOURNE, 390,Flinders MECHANAIDS LTD., (Post couponin Lane. JOHANNESBURG, P.O. Box 4928. Research andDevelopment Engineers, unsealedenvelope Address. DURBAN, Natal Bank Chambers (P.O. HOL. 1120. -Id. stamp.) Box1489). DELHI, 10, Aliyvre Road. HALTON HOUSE, HOLBORN, E.C.1 M 9 CALCUTTA,102,Clive ..Street. 25'2 NEWNES PRACTICAL MECHANICS April, 1944

gthettektibe, kllep7ithes ARE NOW BEING MANUFACTURED and demandspecialcarein an abrasivematerial,suchas repair if the best results are to sulphur remover or sandpaper, a be obtained.Cycle tyre patches before proceeding. In every case Youwil!recognisean of existing makes may be used, solution must be used to secure inner tube made of syn- butitisimportantto prepare goodadhesionto thetube. theticrubberby the letter 'S ' stamped on it. the place to be repaired with at least half -an -inch high. VIFICIMP

/iFti 305

THE " FLUXITE QUINS " AT. WORK " I've mended this weather -vane, see ! WithFLUXITE - but what puzzles me. You can turn her to east And then turn her to west But it still blows from nor'-rard,'! bawled he.

For all SOLDERING work-you need FLUXITE-the paste flux -with which even dirty metals are soldered and " tinned." For the jointing of lead-without solder ; and the "running" of white metal bearings-without " tinning " the bearing.It is suitable for ALL METALS-excepting ALUMINIUM-and can be used with safety on ELECTRICAL and other sensitive apparatus. With Fluxite joints can be " wiped " successfully thatareimpossible by any othermethod. Used for over 30 years in Government works and by leading engineers and manufacturers. OfallIronmongers-in tins, 8d., 1/4d.and 2/8.Ask to see the FLUXITE SMALL -SPACE SOLDERING SET-compact but substantial-complete with full institicticatt, 7/6. TO CYCLISTS ! Your wheelswill NOT keep round and true unless the spokes are tied with fine wire at the crossings This makes ILFORD FILM ON WAR SERVICE. Officialdocuments, sometimes AND SOLDERED. amuch stronger wheel.It's simple-with FLUX ITE as large as newspapers, are copied on Ilford Micro -copying -but MPORTANT. film one inch square for aerial transmission to theHead- THE " FLUXITE " ALL NtECRANICS WILL HAVE\I quarters of the fighting services and to Empire and Allied GUN pyts ' FLUX- ITE "where you Governments. The six British factories of Ilford Limited want it by a simple are contributing their great resources to the vital part pressure Price 1/6 or filled FLUXITE which Photography is playing in the war effort. 2/6. IT SIMPLIFIES ALL SOLDERING Write farBook onthe ART OF "SOFT" SOLDERING andforLeaflets on of films CASE -HARDENING STEEL and TEMPERING TOOLS with FLUXITE. ILFORDmakers Also on "WIPED JOINTS."Price Id. Each. LIMITED FLUXITE LTD.,Dept.P.M., Bermondsey Street, S.E.I April, 1944 THE CYCLIST 49

All letters should be addressed to theEditor, "THE CYCLIST," GeorgeNewnes, Ltd., Tower House, Southampton Street,Strand, London, W.C.2. Phone : Temple Bar 4363 VOL. XII APRIL, 1944 No. 266 Telegrams : Newnes, Rand, London Comments of the Month. ElectoralBlackmail By F. J. C. NEofourcontemporariesinanimpose income tax ;orifevery motorist A few unreasonable people have decided articleentitled" Organised Power "were organised the Government dare notthat they will impose their will upon tho 0quotes the following words from oneimpose a 'tax on motor -cars. Government and upon 'allcyclists. The of its readers :" If they (cyclists) could all It is implied by those who claim to repre-latter must in no way question their views, be organised to speak with one voice they sent the views of all cyclists we should onlybut must worship at the shrine with obeis- would represent a very powerful body." elect Members of Parliament who are pre-ance and supplication, and lay their tribute Their editorial comment is: they do notpared to obey the wishes of cyclists.Pre- of adulation at the foot of Parnassus. care to mix politics with cycling!" Like sumably ifcyclists organised, as our con- oil and water, the two do not seemto temporary would like to see them organised, mingle." "We maybewrongbutit and opposed the use of the roads by motor-Care, ofPumps is our considered opinion that no prospective carsorpedestrians,the roads should beEVERY endeavouris being Made to pro- Parliamentary candidate would lightly ignore barred to motorists and pedestrians. vide more bicycle pumps, but mean- the views of an organised body representing The whole country should be run, appar-while make sure-before turning over any more than 20 per cent.oftheelectoralently, to suit the whims of the Councils ofdiscarded pump to salvage-that itreally voting strength." the C.T.C. and the N.C.U. has reached the end of its usefulness.If the The article goes on tosuggest that we Herewith afurther quotation from ourpump has been discarded, due to lack of must getas many as we caninto ourcontemporary :F` If suchorganised powercompression, it is almost certain that it can present organisations.'The fact is that therein the cycling ranks could be brought aboutbe put back into commission by very little is not any cycling body at present so con-the prospects of our being relegated to cer-effort on the part of the owner.This lack stituted that it can claim to represent cyclingtain roads or cycle paths, made to registerof compression is usually due to the screw opinion.No one has yet discovered whatourmachines, orsubmittoother petty which holds the compression washer in place cycling opinion is,for neither the C.T.C.annoyances, would be farlessthan theyhaving come undone due to vibration. Some- nor the N.C.U. has takena referendumappearto -day. Lookedatinthisway, times the screw thread in the plunger is to ascertain the views of its members.Thecycling and politics have an obvious link,stripped. A fresh lease of life can be given members are expected to support the viewseven though at first consideration they mayto it by winding a piece of 3o gauge copper of the Council of the C.T.C., and as far asnot seem to mix.' wire round the threads of the screw, which the N.C.U. is concerned it is a body whose What is sauce for .the goose is sauce forwill provide sufficient bite to give the pump main concern is track racing.The C.T.C., andasorganisedmotorists -a further lengthy period of useful life. indeed,isso fantastiCally constituted, thatcertainly outnumber " organised " cyclists by Unscrew the end cap of the pump barrel whilst keeping up the pretence of being aabout so to1, and pedestrians outnumberand withdraw the handle.The parts form- democratic body, it need take no notice ofthem by atleast3 toI,the. two lattering the piston of the pump, including the resolutions passed byitsmembers atitssectionsof the community only have toleather washer, are probably trapped in the annual general meetings.The position inbecome organised in a way similar to that barrel,but canusuallybe retrieved by the cycling world as far as representationsuggeSted forcyclistsfor them to imposegently tapping the pump with the open end of cyclists views is concerned, is grotesque.their will, too, on the Government.Could It is doubtful whether, considering the over-any argument be more fatuous or specious ? down.If not, use a length of stout wire to lapping membership, the C.T.C. and the remove them.If the end cap threads have N.C.U.combinedrepresentmorethan stripped, they can be made to bite by means so,000 cyclists, probably far less, out of aLegitimate Claims of 3o gauge wire, as described above. total number of cyclists variously estimated have supported the legitimate claims You should find a screw, a metal cup and as between so millions and 12 millions. TheWEof cyclistsfor many years, and thea leather washer, and possibly a coil spring, C.T.C. publicity notices bear the inscrip-arguments we have used have been based onalthough the latter will usually be found still tion " What do the cyclists say ?Ask thesomething more solid than the threat of theon the plunger rod. If the leather cup C.T.C."Yet the C.T.C. itself does not vote.There are many sound argumentswasher has been mislaid, another can be investigate the Views of its members. against cycle paths as at present constructed.made from the tongue of an old boot or Now, the contemporary from which weThe argumentsagainstotheraspectsof shoe.Cut a circle of leather, sl times' the have quoted above merely reflects the viewscycling politics are not based on such solid'diameter of the barrel.Soak this in boiling which have been so often expressed by some grounds. Whether the C.T.C. and the N.C.U.water, to render it fairly pliable, and then members of the C.T.C., and the N.C.U.,like it Or not, and whether cyclists like it orshape it over the end of a piece of wooden namely, that the Government isafraid tonot, know that the Ministry of Transportor iron rod, which justfitscomfortably introduceanylegislationtowhichthehas made up its mind on certain aspects of inside the pump barrel.Then soak it in oil C.T.C. and the N.C.U. object because theroad policy, and will ignore the threat of theand fix it in the usual way. Government is afraid of the to million votes.cyclists' vote.The unrelenting, narrow, and To re -assemble,pushthescrewfirst This argument has been used so many timesparochial views of certain of those allegedthrough the leather washer (the head of the by these two unrepresentative bodies duringlegislators whose minds are still back in thescrew to be inside the cup formed in the the past5o yearsthatit 'istime it was"'eighties," and who have never taken thewasher) then through the metal cup, and debunked. troubletoalign, their views with modernthen screw it tight home into the end of the These two bodies do not represent thetrends,arenotthe consideredviewsof plunger. The plunger rod must fit into the views of so million cyclists, nor do they even so million cyclists. metal cup ; all you need is a screwdriver. represent the view of their own members on We know that this is also the view of If you experience any trouble ask a friend such question ascyclepaths, rearlights, certain membersof theMinistryof orlocaldealer tohelp. Ifthethread registration, insurance, or any of the otherTransport. We thinkthatthecycling which carries the connector is stripped, use topics which these bodies have consistentlyorganisations have made grave mistakes incopper wire round the end of the connector opposed. policy during the past thirty years.Theyto give it a bite.In the case of a kinked Iftheargumentagainstthesethingshave earned the reputation of being anti - barrel,thiscan usually be remedied by reposes on nothing more solidthan theeverything. They would make no concessionpassing a piece of mild steel rod smaller threat that cyclists will vote against Govern-graciously (it is often far better to concede a than the bore of the barrel into the latter ment candidates, then indeed the argumentspoint here and there, and thereby indicate aand then raising the dent with a hammer must fall to the ground.It isa form ofreasonable attitude), and so they will befrom the outside. electoral blackmail, to which no Governmentcompelled to accept them ungraciously. We Another very important point isto see should subjectitself.One might aswell venturetosuggestthatthebalanceof that the tiny washer at the end of the con- arguethatif every payerof income taxelectoral power will not be disturbed' by thenection where it screws into the pump is in were organised the Government dare notattitude of the C.T.C. and the N.C.U. place. 50 THE CYCLIST April, 1944 Old Timer BereavedFrank Tillman Killed TWENTY-FIVE year oldFRANK TILLMAN, Finsbury Park C.C., recently Sergeant John Denny, decorated with the Polish Cross for conspicuous son of the old-time track'bravery, has been killed in a flying accident. rider, lost his lifeas the result of a flying accident. For the Forces LATEST member of the Broad Oak C.C. to join the Timekeeper's N e w Forces is James Cockayne. Performing equally well on road and track, he had many wins to his credit Role and showed outstanding promige for the future.He is "IlkTORTH MIDLAND now in the Navy. A timekeeper, J. C. Tate,Rockingham C.C., is now in the Fleet Air Arm. Wings in Canada touring member ofthePortsmouth POPULARNorth End C.C., C. A. Smith, has received his SouthgateClub' swings in Canada.He was also promoted to Pilot Record Officer. SEVEN members of the SouthgateC.C.hold Mid -Devon R.C. commissions i n H. M. WITH a creditable accumulation of 33 points, Ron Forces ;44 members are Billing has won the special trophy of the Mid - serving with the Colours;Devon Road Club, for consistency of rides in map - twelve are abroail and tworeading contests, speed judging,paper chases and in enemy hands. treasure hunts.

Tees -side Celebrity Albert Leggett Married . TJAROLD HEATLEY, ALBERT E. LEGGETT, King's Lynn C.C.club ' " former memberof record holder, has married Miss Doris Holmes of the Stockton Wheelers and Boston.The bridegroom holds a commission in the StratfordSt. Mary, Suffolk. champion of the Tees -sideArmy and his bride is in the N.F.S. Cycling Association in 1934, has been awarded theMilitaryMedal for No " 12" in Scotland gallantry in Italy. Alternative A6 ! CONTRARY to previous expectations, there willbe T2' has been advocated that the steep section of A6 no Open 12 -hour time trial in Scotland this year. A which crosses Shap Fell should be, obviated by a Scotland's' Contribution new road up the Lune Valley on a line close to the main rtvER 7o events on the road will be promoted inL.M.S. route to Scotland.Such a road would save Best Tricyclist Scotland this year. sooft. of climbing. CMULLNER, Western Roads C.C., won theMajor - -'Liles Memorial Trophy as the best all-roundCycling Instructors? Preserving Mountains tricyclist in 1943. AN anonymous donor hasgiven. C7,000 to the ofcycling,asofcricket, SPECIALfootball instructors and boxing, have been suggested by the National Trust for Scotland to preserve mountains. Y.H.A. Pioneer Dies National Committee on Cycling tothe Board of rDWARD ALBERT, M.A., vice-presidentof theEducation. . Death of Kenneth Spence A-, Scottish Y.H.A., has died.He was a pioneer of KENNETH SPENCE, a leading workerforthe the Hostels Movement in Scotland. preservation of the Lake District, died recently Rickmansworth Promotions in Monmouthshire. ALAN ORBELL has been promoted from Flying Essex Roads Resuscitation " Officer to Flight Lieut. ;Tom Hart from L.A.C. THE new hon. secretaryof the Essex Roads C.C.to corporal.Both are members of the Rickmansworth Clarion for Edinburgh is A. Wiltshire, 3, Greenway, Woodford Green,C.C., whose latest member to report to the Forces isAN attempt is being made toreorganise the National who would like to contact old members. E. Croth all. Clarion C.C. in the Edinburgh district. National Clarion Jubilee THE National ClarionC.C. attains its this year and the Glasgow Section'plans to celebrate accordingly. ClubNotes Notts Castle Loss PILOT OFFICER E. H. McCORMACK, formerCumbrae Race D.F.C. for Cyclist path champion of the' Notts Castle B.C. hasWEST of Scotland Clarion will again be runningDILOT OFFICER R. B. BERWICK, brother of been killed in action while on fighter patrol over the Cumbrae massed start race.The date chosen J. James Berwick, the former Scottish champion, France. is early in lime and it is hoped to provide a substantial and also a cyclist, has been awarded the D.F.C. prize list. Scottish Cyclist Decorated Out of Commission Handicapping Investzgatiop MEMBER of the Lanarkshire RoadClub, PilotTHE track at Dinnington, in South Yorkshire, has Officer R. B. Berwick has been awarded the been put out of commission, and will not beTHE Scottish Amateur C.A. has set up a committee D.F.C. toinvestigatethepossibilitiesofanational available for competitive sport this season. . handicapping system. Notts Castle Activities Servicemen and Cycling only re-formed a short while ago theCYCLISTS in the R.A.F. at a certain station in theKitching in Hospital ALTHOUGHNotts Castle B.C. has over 30 members. Contact north are being permitted to cycle in club dress, RON KITCHING, the fast Yorkshire massed -start with pre-war members has shown that P. Wears andif their applications are endorsed by the local club roar, has been in hospital for an operation and A. Wynch are prisoners of war and that J. Else hassecretary. unable to follow his usual activities. been killed in action. Now in Y.R.C. Cumnock Reunion ALF. MARTIN, the speedy South Yorkshire rider, THE " Cumnock Reunion" of the West of Scotland Brentwood Road Club's Loss has joined the Yorkshire RoadClub.. Cyclists' Defence Committee attractedzso and TWO members ofthe Brentwood Road Club, Flight was the best social event of Engineers A. Gurny And A. G. Wright, have been the winter season in Scot-

killed in action. land. Speakers included Lord ProvostWelsh,of Glasgow, and Tom Fraser, Welcome News M.P.fortheHamilton HUTTON, SouthendWheelers,previously Division. +-A.reported " missing,"is now known to be in Japanese hands. More Opens THERE will be 7o open D.F.C. for Norwood Paragon Man cycling events in Scot- operational flights, R. Ash; Norwood land this season, the best AFTERParagon 27 C.C., has been awarded the D.F.C. figure of the war years. In Enemy Hands MATTHAMS, Southgate C.C., previously

WM.reported " missing," is known to be in enemy hands.He was captured in the Middle East. John Walker Missing HER() of over zooperational flights, many of them Robert Marshall, secre- as a Pathfinder, Sergeant Air Gunner J. Walker; taryof theWest of Early Birds C.C., has been posted " missing." Scotland Cyclists' Defence Committee, and Barras Road Club Loss Lord Provost Welsh of PRE-WAR memberof theDarrasRoadClub, Glasgow, at the Cum- Flying Officer J. K. Meyler. who was only25, nook Reunion. has been presumed killed. * lei April, 1944 THE CYCLIST 51 The vice-pr?klents of the club for 1944 are Admiral Hefford and Messrs. P. Brazendale, Aroundthe Wheelworl W. H. Crang, J. T. Lightwood and F. J. Urry. By ICARUS S.R.R.A. Annual Lunch 'THElunch held by the Southern Road Records Association at " The Railway Hotel," Purley, on Sunday, February 13th, 1944, can, I think, be considered a success from all angles in that the attendance, the food, the drinks and the speeches were good ; in fact, they were of the usual high order At therecentwhich one has come to expect at any function Roadfarers'organised by this association. Club Luncheon: The 46 who sat down included representa- Sydney Camm,tives from a number of clubs, including the H. G.Wells,NorwoodParagon,theBelleVue,the E. Coles Webb,Kentish Wheelers, the Kent Road Tricycle and Sir WilliamAssociation, Medway Road Club, the Balham Rootes, K.B.E.C.C. and the S.C.C.U. The toast of " The S.R.R.A." was in the able hands of Arthur Slade, the president of the Kent Road Cldb, and the toast was, of course, responded to by Arthur Whinnett, the hon.secretary and treasurer, who is meeting with success in his. efforts to keep the association alive and in working order in readiness for activities in the record world which it' is hoped will be resumed as soon as hostilities cease. The "Really" Cyclist! was a member of the London Central C.C. The toast of " The Record Breakers " was andtheRaleighC.C.,andfrequently j DEALT last month with the definition offollowed and assisted " Goss " Green andproposedbySydney Amey,thegeneral I- a " real " cyclist given by a contributorothers on theirrecord rides, and was asecretaryoftheS.C.C.U., andresponses toa contemporary. Of course,Ishouldskilful steersman of his tandem for pacingcame from W. G. Phillips, of the Vegetarian have used the word " really " cyclist. There'son the Crystal Palace track. C. and A.C., Stan. Butler, and Tom Vickery, something clever about riding a cycle, and He served during 1914-18 in France inwho was making attempts on Fecords as long unless,asourquotedcontributorsug-the Royal Engineers, and subsequently prac-ago as 1899. gests, you ride your bicycle every day in Charlie Bowtle welcomed the visitors and the year, have no other hobbies, and spendtised as an architect in Maidstone.He was aprivate member of the S.R.R.A., alifepress, and responses came from A. E. C. your spareseconds keepingitclean, youmember of the TA., and an early memberHarrison, of the Tricycle Association and cannot expect to become a member of the Medway Road Club on behalf of the visitors. elect " realies."Not so many years ago aof the Roadfarers' Club. The toast of " The Chairman," Mr. J. cycling writer, in giving advice to cyclists on Dudley Daymond, was proposed by how to tour for a fortnight for half-a-crown,B.C. and M.C.M.T.U. President W. H. M. Burgess, of the Anerley B.C., and advised his readers (if any) to travel light, the annual general meeting ofthe.receivedamidst a good deal of enthusiasm. travelling light,in his estimation, meaningATBritish Cycle and Motor Cycle Manu- carrying half a comb and a tooth -brush, and facturers and Traders Union, Ltd., Mr. C.Norwood Paragon Officials stealing the hotel soap! Gilbert Smith (Norton Motors, Ltd.) was In that famous old musical comedy " Theagain elected president of the Union for the GENERAL Secretary, F. A. Burton, 21, Belle of New York," there is a song which ensuing year.In all he has already served Ashleigh Road, Anerley, S.E.2o. Road is apropos the " realies."One of the linesas president of the union for a period ofSecretary, A. Gordon, 25, Hevers Avenue, in the song goes :" Of course, you can never three years. Horley, Surrey. Social Secretary, R. W. be like us, but be as like us as you are able At the same time Mr. G. H. B. Wilson,Tugwell,888a, London Road, Thornton to be!"The rabid cyclist who isusually Heath,Surrey. PathSecretary,,S. U. O.B.E.,A.F.C., J.P.(Raleigh Cycle Co. Ltd.),Harrison, 7, Laurel Street, Dalston, E.8. a plus-foured traintraveller,. ormotorist,and Mr. A. E. Dover (Dover Ltd.), were will tell you tobe arealcyclist,but heelected vice-presidents. Raleigh Record doesn't ride a bicycle himself. IN connectionwiththeRaleighCycle That " Amnesty " C.T.C.President and Chairman CompanythereisaHalf -Century THAVE receivedthefollowingquaint HIS Grace the Duke of Argyll has beenClub. It has a membership of ten em- notice signed by the secretaries of the elected president of the Cyclists' Tour=ployees, each of whom has served for 5o N.C.U. and the R.T.T.C.:" The N.C.U.ing Club in succession to the late Duke ofyears or in, re. and R.T.T.C. announce thatthe generalPortland.Engineer -Admiral E. 0. Hefford The first of the members to die is Mr. A. amnesty offered to all persons ceasing theirhas been re-elected chairman of the council,Marshall, who recently died at the age of associationwiththeBritishLeagueof and Mr. B. C. Young is again vice-chairman. 73. Racing Cyclists oritsconstituent. partsis still in operation. " Both bodies wish to make it clear, how- ever, that this amnesty offer will cease to apply to any person who participatesor assists in any further event not held under the jurisdiction of the N.C.U. or R.T.T.C." Quite apart from the misuse of the word " amnesty," we do not advise any member Sir William Rootes of the British League of Racing Cyclists to delivering his whom the notice is really directed, to take speech on Post-war the slightest notice of it.The N.C.U. and Road Policy, the R.T.T.C. are not the bodies to issue Major H.R. such a notice, and we advise the B.L.R.C. Wading,O.B.E.. to continue withitsgood work without j.P., isin the reference to either of these bodies.I under- chair.Mr. H. G, stand that copies of our leading articles on Wells is on his left. thesubjectofmassed -starthavebeen circulated all over the country. Herbert Charles Scotto SCOTTO, a well-known club- " BERTman in the early days of the century, died on January 16th, aged 66 years.He 52 THE CYCLIST April, 1944

devouring,' and if you are that waytropic downpour washing away comfort' and adding a inclined, the inglenook of an eveningpang to life.Perhaps because I am grown older I see is a place where you can learn- much'these things more clearly, for even the very minor pro-

country lore and many a local legend. phet must serve the apprenticeship of long years; and - For preference Iwould choose thewhat I see is a happier condition of enjoyment and farm, for I like the fare it can provide ;kindly health for all folk who trouble to discover the for I think jt is true that the countryjoy of real cycling, its freedom, its aliveness, its rhythm, folk in the Scattered areas do better inits introduction to beauty, and its ever laughing pleasure. the way of wartime provender thanNo, I am not exaggerating, it has been all these things we do in the crowded cities.Take to me, and now at this fiery moment of writing I verily with you if possible a little tea, sugar, think it is more to me than'all the games I have played. butter or " marg.," and anything in the tinned line that will make you a wayside lunch-cheese is a good stand- Knowledge versus .Ignorance by-and .having done these thingsT KNOW, none better, the woeful ignorance of the there is little to fear. If you are of the Agreat general public on the virtues of this pastime adventurous spirit that is willing tothat means so much to me.I have always known it, riskaccommodation,ifyou hatebut these war years have burned in that knowledge by writing to fix your places (and manythe process of many thinking people taking to cycling cyclists do), then seek your pot for"as the next best thing," but neglecting to buy the the night not laterthantea -time,right type of machine or endeavouring to discover how and havingfounditexplore theto rideit with ease and grace.With what result ? immediate neighbourhood till the fallThe majority of such folk say " cycling is hard work," of dusk. and I've no doubt itis to the individual pushing too high a gear, sitting on the wrong kind of saddle in an attitude reminiscent of that plaything of my infancy, Cycle Touring a monkey up a stick.I wonder if the industry realises THERE is much to be gained bythe harm done to the pastime by this positive propa- 2- joiningone of the organisedganda of the ignorant who go about denouncing cycling bands of wheelfolk to whom you oweand bemoaning their petrol -less fate !I doubt it, and thepresent freedom that cycliststhe few to whom I have mentioned the matter ask me enjoy, and, thus help yourself andwith raised eyebrows, " what can we do about it" millions ofotherstosopreserve It positively makes me tired to think a great game is that freedomthatthegameoftraduced by people who use it only for a convenience, cycling shallgo on from strengthand is not assisted as it should be by manufacturers, to strength as the means by whichwhose interest surely lies in the creation of as many ordinary people can enjoy the blessedardent cyclists as possible. things of the countrysidewithout possessing themeansofmeetingSlovenly Riding the more expensive methods of travel, and incidentally being the healthierIFULLY acknowledgetheconvenienceof the individual as a result.For I believe A bicycle as a daily rider to work and home again, a cycle touring is the happiest form oftotal of fourteen cycling miles most days of my life, holiday -makingextant,shouldbe but I resent intensely the attitude of so many people encouraged among old and young,who smile in a superior manner when one mentions and be the main means of bringing the art of cycling.It is so ridiculous. You can no more home to thepeoplethewonders .ride a bicycle slovenly and expect to get the best from it, and glory of the land of their birth.than you can play golf or_billiards without paying any Certainly to -day it is the one meansattention to style.That most people ride slovenly than of making holiday travelascom- otherwise -is an, observable fact, so much so, indeed, fortable or as vigorous as you want it that when you see a bicycle being ridden by an individual Sheepstor, to be, with the dictation of time andas the machine should be used, you remark on it.It place and distance under your ownhas become an accepted thing to say a man can ride a Dartmoor village. bicycle if he can preserve balance and steer a straight hand. course;which, of course, is just nonsense, for that performance merely constitutes the rudiment., of the

The Call of Spring Tell the Lads business.And it seems to me no moret-probably a is on the threshold, and the year is looking LL of which has been suggested by astreak ofgreater number-than seventy per cent. of bicycle riders SPRINGfine,- considering the parlous conditions Pertain- 4-4warm sunshine falling on me as I rode to work.never go farther along the road towards the making ing in this war -weary world. The thought Of holidaysWhat a miracle English sunshine can work in theof the perfect cyclist.If the G. P. won't trouble to arises- automatically ,with the advent of the blackthornhearts of men. Before me is a letter from a lad I knoW play the game properly, then cycling will remain "hard bloom and the bird song, for who can resist the tempta-who is standing to attention in India, and through itwork " c.lk...ept to those of us who love this easy rhythm tions to think of far -away places when there is warmthruns the nostalgia of an English spring wherein he of manly, healthy travel ; Which means the comparative in the sunshine, and a south-westerly breeze breathes chattersof bosky hedgerows,of shyviolets,andfew who have discovered the supreme part cycling can beneficence over the land ?We work, yes, and the tie." covi,slips from a Devon combe." How much we oweplay in a life of ever recurring freedom from the hide- and the toil has sapped some of the joy from life, andthese lads, we old stay-at-homes who switch on the bound conventions of existence.I am not exaggerating the long winter of blackout hasfrayed- our goodnews and so often forget to think about our jolly boysthese points for they are open to proof by any competent tempers ;so it is little wonder if we all look forwardwearing away their youth in desert places and foreverobserver, and almost unconsciously the average motorist to a break, a few hours of real freedom to carry us todreaming of home and the lanes that circle it.Itpays a compliment to the club cyclist by saying, amid those spots of which we have been dreaming throughseems to me if we did not take our opportunities ofthe heat of an argument, that his type are never any the dark days.. But how shall we get away ?If onemaking ourselves more intimate with this beautiful^trouble-they know how to ride !Why do they know ? reads the signs aright-and that is not difficult surely- country we should be neglecting a sort of post-warBecause advice is freely given and experience exchanged it is only the cyclist and the walker, and espEcially the duty to these boys who are making the trails of victoryamong companions. Now I want to see that advice and cyclist, who will have the freedom of the road.Hefor us, and the least we can do is to mark the trailsexperience handed to every rider when he or she can kick off from his own doorstep and return thereuntO .of joy for them when peace returns, and write and tell starts cycling.1 do not want good riding to- be the at the appointed time, without asking any kind of travel them about it.It is one of the things we ought not toperquisite of the club folk ;and I know to a certainty assistance from theoverburdened transporipeople, neglect, for I have learned by contact with these lads that if this desideratum could be achieVed, not only The value of a bicycle-always great but too often how a letter full'of the simplicities of a country journeywould the " hard work " slur disappear, but cycling unrecognised-has been magnified enormonsly in thesefills them with a joyous longing for all those things forwould very soon become ip the mind of the million, difficult times, for it presents to its waiter ad advantagewhich they are fighting. Their jun is the burning sun,the finest, simplest, healthiest and freest travel method that is inestimable, particularly if that °Amer isfit their rain, not " the gentle devrfrom heaven," but theextant, and the held for its expansion would be limitless. enough to range afar, and take front his Vief.holiday the passing glory of its hours. Those of you who ride mainly for the convenience of movement I would adjure to try the fine adventure of Muting, to change your county for a brief spell, to pass beyond the confines of the daily journey and so make a wider ante& with this lovely land, never lovelier or more capricious than when spring decorates its outlines.It may need in you some measure of resolution if you have never gone awandering ;but these are the days of good resolutions, so be you worthy of them. Seeking Accommodation THE question of accommodation alongtheroad has frequently been raised by people who have felt .inclined to take me at my word and try cycle toliring, and it is certainly a pertinent question when one hears so much of the difficulties concerned 'with hOliday,making.Personally I have found no trouble, althediri I have not always been fortunate in acquiring the ite.ctimmosIstion I would like. My modus operandi is to write for a place within fairly easy reach of home, and if the holiday is of short duration, make that my nightlyanchorageafterexploring the -countryside within striking distance.If the holiday runs over the sleek I usually try to fix three or four days at -each of two such places and thus obtain a wider field of roaming. There are still numerous farms and cottages strewn about the land whose owners are willing to attend to the needs of the stranger within their gates providing he is not too fussy, a,nd books the accommodation well ahead.I know from experience that such homely Places, while not perhaps possessing the amenities of Winchester :the hospital of St. Cross, the Grand Hotel, preient the visitor with a far better from the banks of the ltchem table, that meal -times can be arranged tofityour desires, that jolly good lunches are packed for wayside April, 1944 THE CYCLIST 53

* A cyclist"runner," travelling " light " throws a weight of over200lbs. uponhistyres. Over grit, flint, mud and gravel, Firestone tyres take the strain.

theyuse -Firestone tyres Your help to meet this great demand is even more urgent.Tyres are now made withsyntheticrubber andthey must be kept properly inflated. I 54 THE CYCLIST April, 1944

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By CYCLORAMA H. W. ELEY have always vowed that of England's pleasant counties, Somerset was one of the very fairest ! What gloriesitcontains ! Whatromanceliveson itsborders ! Glastonbury, withall the roniarIce of the Holy Grail, and the Flowering Thorn ;the magic Vale of Avalon, and all the fame and '`..-,"-,,.,7.,,.--..- ,...." fancies his ,,-=`'7,,,z,,,,,.,,,,,,,,_., of King Arthur and Gentle , .. Knights.Yes, Somerset is good . . . I love - itslushmeadows, anditswild, rugged zorztiodWIMCf------7fic-I,,,44,r,,' Exmoor, with the red deer, and the spell of the Lorna Boone land where the great John Ridd fought, and rode, and wooed, and won.Men of Devon may not agree _---,------,r- -,-.--,._:_.- --:-... with this praise of Somerset-but one can i! love Devon and Somerset too, and because I yearn for Exmoor, does not mean that I 1 I -TT! iiii rni ,,....,..., lit it am insensible to the weird lure of Dartmoor, or the beauty of the Devon coast.Some fine day, when one can journey far afield again, .2-=_-_, - - ) -Tr -, -7.L-r---,-*--It-7,---, we may enjoy cider in Somerset, and cream --:_r..-----___,--;----7---.i,,'., -:---,--,..:- . -. . . in Devon .. and in some inn in the latter _L ---f- 6n. county; sing with Devonshire men of the '''&74.'.'1."'' ''' ' el. 'IT4-49'011afreT/WOS4t*,3,:reprirg - 2,4 10.ekt deeds of Drake. . . . "Synthetic" Rubber Tyres SINCE .thelossofthe Malayan rubber plantations we have heard much of " synthetic " rubber, and most of us have .^AOrrisTOHL mANOR... -2. had pleasant visions of scientists_ and tech- bROOKE... i-; nologists producing, rather in the manner ISLE. O' ,GHT. of conjurers, some wonderful product which completelynullifiedthetragedyofthe 2,....scoel Malayan loss . . . a product called " syn- Cycle Cleanliness to him, ri in and snow, and hail and sun-thetic."Well, the expertstell me thatit shine, are vital things-connected with his HAVE been struck recently by the poor was not quite as simple asthat, and also livelihood, and not merely caprices whichthatthe -factthatacertainamountof treatment which many cyclists seemmay interfere with .some passing engagement content to give their machines.An inspec- " synthetic " is now available does not solve ti tion of cycles in a factory cycle shed willor enjoyment. And there is something goodour troubles.Tyres cannot be made solely and clean about rain . . . I love to feel it onof" synthetic "-there must be acertain convince one that many riders seem to thinkmy face asIwalk the highroad ;Ilike that a cycle never needs cleaning ;that rust proportion of natural rubber ; and therefore to listen to it gurgling in the gutters,,,and, thereisstillthe imperative need for con- isa good thing -to allow on plated parts ;best of all, I like to see the rainbow whichtinued economy in the use of rubber and and that gross neglect is the best way to getso often follows a shower.So, let us not easy cycling.Now, busy though a man may in the treatment and care of tyres. grumble at the rain... it may make all the By the way, the cyclist should be inter- be, he can surely find a little time to givedifference to those crops which are such aested to know that he can identify a tube his bike that very small amount of attentionvital part of our salvation in these red days which :s necessary if the machine is to run which contains a proportion of "'synthetic," of war. . . because itis marked with a letter " S."I as sweetly as its makers intended it should ! believe that covers containing " synthetic " I commend a " spot of cleaning " to thoseLack of Snow! are marked with a red patch or disc.Look riders who neglect their mounts ..they ITALKED, the other day, with an oldfor such markings!And remember that will be pleasantly surprised at the greater countryman, and our conversation" synthetic " tyres need extra care! ease of their riding. turnedtothateternaltopic. . .the WEATHER. Both of us remarked that this U S.Soldiers Awheel had been a winter novel because of the lackThe. Best County FROM observation ina provincial town of snow.True, some mornings one has EVERY cyclist has his own ideas of the wherethereare some hundreds' of seenafeeble attemptatsnowing, butI perfect village and the perfect county ; American soldiers; I have come to the con-cannot recall one good " fall" in the Homethe man from Devon will not allow that clusion that our American cousins are quiteCounties or the Midlands-the areas where I spend my time these days.Now, person-any county can beat his own land of the keen cyclists. . . . Isee many of them west ;and the man from Sussex is equally awheel and they seem to be keen to seeally, I think it has been all to the good thatvehement about thegloriesof his native something of the English countryside whilewe have not had snow ;the fuel firoblemshire ; and as for the man from Lancashire, they are with us.And what a good and isstill with us, and in any case snowfallshe will defend the beauty of the county make for transport difficulties ... and trans- desirable thing it is ! Even in early Marchport has enough burdens to carry just now! againstall comers, and prove thatif you the English sceneis good and satisfying,But how Iloved to hear that old country-Wjudge Lancashire by such places as and I hope that many of us will try and goman talk of the " terr'ble " snowstorms of arrington and Bolton and Widnes-then riding with these boys, and tell them some- youare doing a mighty injusticetothe his youth!I wondered .. . because I have thing of the matchless story of the Englisha feeling that not even the fiercest stormsCounty Palatine.And it is true . . . Lanca- roads, an I towns, and old landmarks by theof the 'eighties surpassed those snowstormsshire can show us some real scenic glories, wayside.Cycling is a truly fraternal thing, and blizzards which visited us in the firstas any cyclist who has toured init knows and I am sure that many cycling Englishmen two winters of the war.The factis thatfull well.All thisis because I heard the would be happy to go for spins with ourage is apt to gild the picture, and underlineage-old argument about " the best county " cousins who must, at times, feel very lonelythe scene. being carried on with heat and good humour in what is,to them, a strange and curious only last week . . . in an ancient inn not country County Dialects far from Maidstone.The singularthing EVENinthesedaysofstandardisedwas that there did not seem to be a " man Welcome Rain speech, and scorn for country dialects,from Kcnt" or a "Kentish Man " in the 'EBRUARYFill -dyke," may, or mayone still finds enthusiasts for the talk of thecompany to take up the case for that county, -L.not, have lived up toits name, butshires, and the pleasant dialects of our differ-which was, ina way, the very cradle of my recent talks with farmers indicate that we ing counties.I talked the other day with aEnglish Christianity-that county which can " could do with a drop of rain "-and whenman whose accents betrayed that he came show ustheglory of Canterbury ;that mostin it comes to matters of weather,Iam always from the West Countree .. . and I found countywhich is richerthan inclined to take the word of a farmer, forthat he nailed from Somerset.Now, I Dickensian memories and legends. 56 THE CYCLIST April, 1944 _

to others as they would be done by.During, this lullperiod, when thevastmajority of motor -cars (other than military) are taking a long rest, would it not be a good idea to attune our minds to future possibilities ?Somehow Ithink so.

My Point PARS Definition SOME sapient individual-an alleged cyclist, too- of View laid it down recently that " the careless opening of motor -car doors is not a crime."Of course not.It is simply a genial way of showing your ignorance-of displayingyour completedisregardforany Other 5 by WAYFARER road -user! Chestnut IHEARD the other day, as something new, a joke which Ifirst encountered at least go years ago. Traffic congestion has never -been anythingIt concerns an ingenious lady cyclist who complained like so severeasignotantpeople makethat her lamp went out every time she ran into anybody. itout tobe, and nowadays, ofcourse, No doubt this will be new to some people, though ,`5'it17--...- oneliness is the keynote of travel, taken as ancient history to me. a whole.When we return to normal, after' the end of the war, and our main roads are infested with the people who can afford Take Care of Wartime Cycle Tyres to run motor -cars (together with a lot ofTHERE are over ten million cyclists in'this country, others who can't, but do !)we cyclists which means that there ,are over twenty million St Mary tkeViTrs. Adderla.ry(0.....) may have to pin our faith to lane -riding, bicycle tyres in use.That amounts to a great deal of withoutinany way relinquishingour rubber so every cyclist must play his part in conserving right to use the main roads.As a matterthis rubber to the utmost. offact,thereisample room onthe War grade tyres, of course, need extra care, and the Eclipsed roadsof this country for allof us.A great. dealbest way of servicing them is to keep than inflated HARDLY was the ink dry on one of my recentof discomfort and trouble would be avoided if toohard.So pumps should be used regularly and often paragraphs, in which I stepped -up battery lamps, percent.ofeveryclassofroad -user,whetherto ensurethatthe share of the nation's precious than I was displaying my' Identity Card to an inquiring afoot or awheel (and irrespective of the number ofrubber supplies entrusted to cyclists is not wasted in policeman and he was laboriously jotting down the -wheels), would adopt the golden rule of always doing any way. information he required. For why ?Well, merely because I was cycling in the dark without a rear light I The battery had died on me a few miles back, and I had fitted a new one.This serged for a period and then passed away-or elsesorrTething went wrong with the bulb, and I didn't happen to have a spare with me. -The difficulty of replacing the " innards of battery lamps is only one degree greater at night Notes of a Highwayman than in the day, and so I rode on, until this inquisitive feller sidled up alongside and wanted to know all about By LEONARD ELLIS it.We parted friends, of course, and I completed Forfarshire left Hull for Dundee. A fault in her boilers my journey as a cyclist and not as, a pedestrian. AKing Alfred's Grave caused the ship -to become unmanageable, and during few days later a little note came from the police saying THERE are many who declarethat Winchester isthe night she drifted on to the Hawker Rocks.The that on this occasion it was not propoSed to priyceed the finest old city in the' world, and the touristboat was broken into two. parts and the captain and any farther, but . . ! And so I shall have to be careful, as I usually am.Meanwhile, if you want to know mywill agree at any rate that it has Many claims to thishis wife were washed overboard:The.cries of the honour.Winchester is not the only tow's in the south survivors were heard in the lighthouse, but William opinion of battery lamps ,it is just as low as it can be !of England that makes a big point of keeping aliveDarling, the father of Grace, declared that it was the memory of Good King Alfred.\Vantage is saidimpossible to do anything to help.Undaunted, Gface Burnt -out to be the birthplace and Winchesterisgenerallyseized an oar, her father followed, and by great skill regarded as his last resting -place.Here as in \Vantageand courage they reached the rock and rescued the T OFTEN wonder what happens to some ofthe survivors. Aultra -enthusiastic cyclists whom one meets from is a huge statue of the king reminding everybody that Five of the crew and four passengers were time to time, and especially do my thoughts go backsuch a man really existed. Winchester is also connectedbrought tack to the lighthouse and looked after until to that sturdy youngster with whom I rode for a fewwith another great figure in English history, that ofthe storm abated 'and they could be transferred to the miles on a Sunday evening three or four years ago.King Arthur, buthert.history and myth areso mainland.There are many who deny that Grace He was an ultra -enthusiast, if ever there were one. interwoven thatitisquite impossible tosort theDarling and her father were really responsible for this He told me that he generally did a ride of about xso wheat from, the chaff.One 'may see in the great hallbrave act, but such doubts are generally ascribed to miles on a Sunday, irrespective of the weather (duringat Winchester what is reputed .to be King Arthur's local jealousy. the summer season, at any rate).When I asked himfamous round table, but here again we what he felt- like on a Monday' he admitted that helook with many doubt n the autheh-. was a bit tired, but he went for a as -mile jaunt in,the t lefty of the claim. Howel' Winchester, evening-a " hair of the dog " you know-and then with its glorious old cathedral, its wealth he feltall night.After parting from him Ifellto of old houses, its quaint city gates, and wondering whether he was proceeding on the rightcountless other attractions, cannot fail lines.Inother words, was he overdoing things ; to proVideendlessinterestfor the was he contracting indigestion through gulping down visitor. We mustnotforgetthat cyclingin such quantities ? Icannot answer theWinchester was 'capitalofEngland questions, but, having seen so many cases of burnt -outevenbeforeLondon, and thereis enthusiasm,Ifear the worst.In my view-and Isomething in the old city that shows yield to none in my enthusiasm for and love of thethat she has notyet forgotten the pastime-it is a mistake to make cycling the be-all and dignitythatwasoncehers.The theend-allof one'sexistence.'Phe game hasso cathedral does not impress as some of many faCets, so many possibilities-it can provide sothe English cathedrals do, but on closer rich an endowment of gifts-that it,seems to me to be acquaintanceoneseesthedignified quite wrong to crown one's wheeling activities into abeauty of the old building with its few months and then to be so thoroughly fed up thatWealth of Norman architecture.It is one fades for ever from the ranks of cyclists.This remarkablethatthecathedralstill happens time after time.There are observers whoremains to us, as almost within living say that the life of the average cyclist is two or threememory the place was practically in a years, and it is to be feared that there is a measure ofstate of collapse.It had been bOilt on truth in the statement, which involves so great a lossinadeqUate foundations, and after hun- tothe pastime, and an immeasurable losstothedreds of years it was found that walls individual.Be an enthusiast, by all Means-but avoidwere cracking and sinking and that the thatultra -enthusiasm which burns so fiercelythatwhole fabfic was in danger of coinplete there is nothing left in a few months' time. collapse. The work of underpinhing Cycling is a recreation for all ages' and for all times. the vast structure is one of the epics of One's wheeling programme can, beinfinite.Whysalvage, as the boggy foundations wefe choke yourself with cycling :why not let it serve youremoved andreplacedbyconcrete rightthrough. yourlife,bestowing upon you theblocks, piece by piece, over a period of unfailing bountyitpossesses ?Think itover, mymany years.In the cathedral are six ultra -enthusiastic friends. ancient chests containing the remains of twelve Saxon kings and bishopS. The remains are mixed together and

Seclusion it is impossible to point to any one of rAN one of the bleakest of those bleakSaturdays them and to be sure that it is the body -/in February I introduced an oldacquaintanceof Canute, or Edmund, or William toa tea -place Ihad recently beenpalrOnisirig,'-a Rufus. field cottage whose windowt give one an acceptable glimpseofthe Malvern Hills-and, in return, he brought me a new way home, avoiding main toadsA Northern Epic as much aspossible.What a joyitwastobe traversing' lovely, secluded lanes-yes :lovely evenMANY miles from historic Winchester in a Month of greyness !-*which were full of little liethe Fame Islands,off the hills and amply supplied with awkward bends andcoast of Northumberland.Longstolie corners !Until we stopped to light up, a full hourLighthouse on Longstone rock was the after starting our journey, we did not seea soul.home of Grace Darling, whoS? feat Thena motor -car came along, and we encounteredof heroism will never be forgotten. hardly anything elsebefore suburbia was reached.In September,1838,the g6od ship Norman Cloist.ers, Winchester Cathedral. HIGHSTONf UTILITIES -*VA70),5-iilii min le CRYSTAL SETSa """""""d"RF,AL RADIO THE ULTRA LENS BECE1 VER, s and I.fittedwith' a GALPINS CRYSTALPERMANENT ELECTRICAL STORES PrETKOTOR AIDS PRODUCTION WHY NOT HAVE " FAIRVIEW," A SET IN YOUR LONDON RD., WROTHAM, KENT. OWN ROOM OR ThispatentedElectric -Magnifying AN A STAND-BY ? Lens of the most modern design has TERMS CASH withORDER. -9/6, -post 6r1. -s-/ PERMANENT stood the test for the past few years No C.O.D. DETECTORS,8/0. and has proved to countless industrial post ad. Firmsitsextremeandsustained liegret no orders ran be accepted front Eire BELL TRANSFORMERS or Northern Ireland. reee.guirifateed tirins-fo''&1ra Werk usefulness for minute surface exami- W; giving 3, 5 or S volts nutput at1 amp., nationsofeveryconceivableobject, ELECTRIC LIGHT CHECK METER, operatelL4b. burger or bell.Msii for A.R.P. light well-known makers, .first-class condition, In hethrr7, or shelter.", PRICE 9/0, POST 3d. metals, tools, fabrics,fibres, raw electrically guaranteed,for ,.C.Mains MORSE KEYS materials. 2110-250 volts 50 ey. 1 phase 5 amp. load, Practice on 17' rekulatioi else PariPing Key.Our 10/- each ; 10 amp. load,12/6,carriage 1/.. heavy brass inorklia on a wooden baae, is .,WATT WIRE ENDResistances, new boa an aulluirpstAinf nd nickel contacts.. Key is It very useful in Tool Rooms for wired to Work basalt or/teltlamp by trals.,s 41z.4 examination of freshly hardened tools, and unused, assorted sizes (our assort- batterySr ` the-. alinsfortilerdescribedabove. gauges,etc. Itwilldetect hid den ment), 5,1 per doz., post free. BRASS KEY, 0/9, .2h:Omlum Rietkl. '216. ,W.O. SOLID BRASS LAMPS(wing type), one - leodel with heavy bfkair bar and the addition of a fractures and will prevent tools with front !medal, 9/6., Chn3infuni Plated, /0/6. ; Tke holemounting,fitteddoul decontact above keYs are supplied to the Services for Matte ordinarilyundetectablecracks-cracks small Bk. holder and 12 -volt16 watt instruction.Slightly smaller Ker. 4/4.7-altili.i.;C,Y, that occur in the hardening process- bulb, 316 each, post free, or 30/- per doz., mountedonbakellte base to'setheswitha brizzer, carriage paid. 5/-. Should forr renuArea'CompletetAtrit;nur D.X.9 being placed in service. Bet consistsor a heavy key ainfrated on a Jag Revealing everydetailwithstartling TUNGSTEN CONTACTS,8/loin.dia.'a poi.bed bi'sia, 10111. tegethef with a Irgaer, exactness, highly magnified and brilliantly pair mounted on spring Wades, also two Nash lamp.- bulb and'holder with taii switches VS highquality pure silver contacts 3/Isin. bring either Into cireidt. Terminate Ore also provided illuminatedinnaturalcolourings,it also mounted on spring blades fir for for distant sending an4 receiving.' 19/0. PMad presentsinmanyinstanceshitherto heavy duty, new and unused ;there is MICROPIrIONg§ enough base to remove for other work. Joe.414 thing for Iliforna9 unsuspected data which can be used cond¢rtaroomto room Op Price the set of four contacts, ¢/- post free. Lhuni4atton, etc. Bakelite table to advantage. model, 6/9: tYilras ROTARY CONVERTER,D.C.toA.C. shoWn,8/6.Post66.Super Input 22 volts D.C. (twenty-two). Output Model on stand. IX-.Pilling Price £4-5-0 complete in case with spare 100 volts at 140 ItI/A. 50 cycle, single instructions included. Mike but-, bulb, battery and transparent measuring 'phase,ballbearing,illfirst-classcon- tom, 2/6.Transformers, 410.. scale. - elision, no smoothing. Price, carriage paid, BUZZERS 23. Scliirsitieiihrie"al model,8/0. No.3 HEAVY DUTY doable MASSIVE GUNMETALWINCH;complete _ coil. 4/9. i/ht 3d. BRITISH MADE THE ULTRA LENS COMPANY with long handle, for use With fin. wire SOLDERING IRONS, AdjustableBit,allparts cable, weight 50 lbs., condition as new. replaceableandfullyguaranteed. 200)250v., RICHARD BOCK Price13,carriage paid. 60 sans, 9/6; 150 watts. 12/6. poet Full particulars SEND ld.S. A. E. FOR LIST B.P. OF USEFUL RESISTANCE UNITS,fireproof, size 10in. ELECTRICAL ACCESSORIES. Money refunded if on request 75, Fipsbury Court, FINSBURY bylin.,woundchromenickelwire, not completely satisfiedLetters only.Flow resistance2 ohms tocarry includepostage,anye.seesawillberefunded. PAVEMENT, LONDON, E.C.2 10 amps. IIIGUSTONE UTILITIES. .r- Price 2/6, post free. 56.New Wanstead. LONDON. 1/.11 AMPMETER,switchboard type, din. dia., for A.('. D.C., one reading (1-300 amps., SCALE BUILDINGS: "00" one reading 0-100 amps, either meter, Val BALLAST BINS... 9d. 50/-, carriage paid. fluid PLATELAYERS' MATRICULATION " Easilythebest soldering 2/6 3i6 & 5/6 obtainable." COAL OFFICES... 3/9 6/-&9/9 ROTARY CONVERTER,50vD.C. input, -oregv..rewegiss This statement by a regular user WEIGHBRIDGE A.C'. output 75v. at 75 millianips, in first of " BAKER'S " exPresses the 5/. class condition.Price30/-each, carriage Whatever your age, you can now general opinionof motor and WATER TOWERS paid. study for the all-important Matric- engineeringtrades.Soldin 6d., ENGINE SHED TRANSFORMERcores, ulation Examination at Inkife- on II- and 116sins. AlsoinBulk. GOODS DEPOT 12 6 will re -wind for BOOKS: a 1 LW .Auto,presentwindings not " NO PASS-NO FEE!' " British Railway Rolling Stock,"9/6, guaranteed, 22/6. " MATRIC " is the adeptetP*- by post 5/, port to all careers, and opens up "IE. chiennegai nThet,-)da5y.," b(ys tipagsi ot n5ar6y steam and TRANSFORMERinput 230 volts, output opportunities which would other- 2,000-1,000-0-1,000-2,000 atf amp. " History of G.W.R.." Vol. 1 (2 Parts), 1833- PriceEL wise be completely cloied to ydti. 1863. 21,-, by post 21/8. Vot. II. 1063-1021, 10;6, by post 11'-. Ensure the success and security of WANTED GAUGE '0 and 00 LOCOS and 3 PHASE TRANSFORMER,410v.to you and yours through post-war ROLLING STOCK. 240 v. at 2 kW., size of core14in. by difficultiesby writingforour TsIdesley & Holbrook. 109, Deansgate. I tin., 5 sq. in. section. 810. Manchester, 3. valuable "Guide to Matriculation" ROTARY CONVERTER,input220v immediately-FREE and without D.C.;out put 18 v. at 28 amps., 17 10s. obligation. B.T.I.(Dept. 160), SIR WM. BURNETT & CO. (CHEMICALS) LTD. 356, Oxford Street, London. W.1. t. West Rd.. Islewortb. Middx. Hounslow; 0476 Compact, well Balanced, Steel TAPE MACHINE,fittedKlaxon 220 v P.C. motor, geared -drive, rheostat, con- WIND CHARGER TURNTABLES trol,18 ohm relay, complete with tape consisting of " V " BED, with adjust- reel and tape, 810. it able " Strap " toTAKE ANY CAR ASSIMPLE, TO DYNAMO, RECTIFIERS,metal, HP) 500 v -60 WE WILL PURCHASE USE AS A PEN Tail post, 2 -positionTAIL 15,-; WO, 5,'-; H 120, 15/-:large type. LOCK,etc.,onSTURDYMAST size 10 x4in., approx., 100 v. f amp., 20,1-. Models and Machines of every Willetchonany BEARINGS. (NOoutsidewires). metal. Quicker than WITHinstructionsforeasily made BLOCK CONDENSERS,4mfr,2,500 v. description. Railways and machineengraving. Mast, sheet metal Tail, Prop, etc. Price working, size 6 x 5 x Sin., 30/-. parts from gauge 00 toIS. From Dealers or direct, 251- each incl. strong box and postage. Boilers, Engines, Boats, Mec- sand for built. Z. 1:t." P.M. Barham, " Hilltop," Bradmore TRANSFORMER, input 200-250 v, ; Green, Coulsdon, Surrey. output500-450-400-0-400-450-500v.at cano, etc., etc.State fullest 250 inA.; also 5 v.-4 a, C.T. twice, size z 7 70/, particulars and price required Easily Made in first letter to save unneces- VOLTMETER,din. dia., switchboard type, sary correspondence. by cur method RATCHET & REVOLUTION for A.C. or D.C., range 0-700 v., clear J.HALLAM scale100-700v.,veryevenreading. We also have FOR SALE fair COUNTERS Price33. stocks of the above.Stamp & SON, /1,1? for with requirements. LeolleiNo.1813 AIR PRESSURE GAUGEbyfatuous uphill,Poo's, Sinai maker,10in. Dorse'. up to dia.,reading 0-4,000lbs. BOTT ER ILLS,Degroggt, 6,000 r.p.m. per sq. in., as new in ease,67 10s. MINIATURE PETROL ENGINES (or B. & F CARTER & CO SWITCH FUSEinwrought HIGH STREET, CANVEY, ESSEX Aeroplanes and ,Speed Boats. I TO.. BOLTON S ironcase, 31. pa itanl.o,. 3 -way for 400 v. at 40 amp.,45/-. BUZZER WAVEMETER,completeIn LARGE DEPT. FOR TECHNICAL BOOKS INVENTORS teakcase,range10to5,000meters condition as new.Price 30/-. SILVER PLATING SETS MODELS' madebyengineer who as supplied to Electroplaters, but in specialises inallPatent Work.Design, MOTOR -DRIVEN PUMP foioil or water, miniature. for small parts. etc.. Instruc- Drawings, and marketina of patents.- motor 220 v, D.C., 1,250 r.p.m., maker FOYLES tive small sets.1.0/- ins. post.Send FollyI norInn W C 1 lid. stamp for printed folder. " -Keith Blackman," inlet, and outlet fin. * BOOKSELLERS TO THE WORLD * Price16 104. New and secondhand Books on MERCURY WANTED URGENTLY TOOLS Engineerng and all other subjects. high price paid, write for Quotation. PLEASE NOTE.- Iwould greatly appro 119-125, Charing X Rd ,-London, W.C,2 S. CANE & COMPANY, NEW MACHINERY. Foressential vial e price lists or catalogues of Railic Open 9 a.m.-6 p.m. including Saturday. ARGENTA BRAND PRODUCTS, work only. 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