that brings in aGOOD INCOMEis not a luxury, A XMAS BOXit is aSOUND INVESTMENTand results in A PAYING CAREER A NettProfitof Hundreds of Pounds Per Annum possessor to the front.It is no use waiting for I HAVE HELPED bettertimes. Theidealopportunity never THOUSANDS OF OTHERS arrives. We have to make the best of existing conditions.Therefore, delayisuseless:itis worse, it is harmful. And when Isay thousands, I do not If it is your desire to make progress and establish exaggerate, as I can produce well over yourself in a good career, write to us for free 10,000unsolicitedtestimonials from particulars on any subject which interests you, or gratefulstudents who, through our if your career is undecided, write and tell us of Postal Training, have achieved their your likes and dislikes, and we will give you practicaladvice as to thepossibilitiesof a life's ambition. vocation and how to succeed in it. You will be Duringthelastwar many people under no obligation whatever. It is our pleasure learned how to write short stories, to help. We never take students for courses etc. unless we feel satisfied they are suitable. Do To -day a number of them are not forget that success is not the prerogative of world -famed authors. the brilliant.Our experience of over thirty By becoming efficient in your vocation you can years proves that the give the best service to your country and to will to succeed achieves yourself. The more you increase your earning more than outstanding power the better itis for the country and for brilliancy. yourself personally. War or no war, earning power always brings its LET ME BE YOUR FATHER XMAS DO ANY OF THESE SUBJECTSINTERESTYOU ? Accountancy Examinations Civil Engineering Mining. All subjects School Attendance Officer Advertising and Sales Management Civil Service Mining. Electrical Engineering Secretarial Exams. Agriculture All Commercial Subjects Motor Engineering Sheet Metal Work File E. Examinations Commercial Art Motor Trade Shipbuilding Applied Mechanics Concrete anti Structural Municipal and County Engineers Shorthand (Pitman's) Army Certificates Engineering Naval Architecture Short Story Writing Auctioneers and Estate Agents Draughtsmanship.All branches Novel Writing Speaking in Public Aviation Engineering Engineering. All branches, subjects Pattern Making Structural Engineering Aviation Wireless and Examinations Play Writing Surveying Banking General Education Police, Special Course Teachers of Handicrafts Blue Prints G.P.O. Eng. Dept. Preceptors, College of Telephony and Telegraphy Boilers Heating and Ventilating Press Tool Work Television Book-keeping.Accountancy and Industrial Chemistry Production Engineering Transport Inst. Exams. Modern Business Methods Institute of Housing Pumps and Pumping Machinery Viewers, Gaugers, Inspectors B.Sc.(Eng.). Insurance Radio Communication Building, Architecture and Clerk or Journalism Radio Service Engineering Weights and Measures Inspector Works Mathematics Road Making and Maintenance Welding Builders' Quantities Matriculation Salesmanship.I.S.II.A. Wireless Telegraphy and Telephony Cambridge Senior School Certificate Metallurgy Sanitation Works Managers If you do not see your own requirements above, write to us on any subject.Full particulars free.

EVERY DEPARTMENT IS A COMPLETE COLLEGE: I STUDY AT HOME IN EVERY STUDENT IS A CLASS TO HIMSELF YOUR SPARE TIME \\MMIII11111111111111111111/1/1/111 JOURNALISM Ots. C KU/ Short Story, Novel and Play Cs,t( ,/ CAN YOU CHANGE MY 40 Writing EXPRESSION ? rM / 75f77%.....,There is money and pleasure in Journal- IFSO, YOU MAY BE _&; ism and in Story Writing. No apprentice- 4-74 ship, no pupilage, no examinations, no THE ARTIST THAT ..442'1:41TRII[rni t'o COMMERCE IS WAIT- outfitnecessary. Writingfornews- ING FOR papers,novels, orpictures is not a gift; 111-1:11W1117--111."-71701/11 itisa science that can be acquired by Just tryitforyourself. - 1111 diligent application and proper guidance.

Trace or draw theoutline It is the most fascinating way of making G94';"Q4 sf and then put in the features. pastime profitable. Trained ability only There are hundreds of openings in connection with hi is required; we do the training by post. Humorous Papers, Advertisement Drawing, let us tell you about it. Posters, Calendars, Catalogues, Textile Designs, ittteter-s:: Book Illustrations, etc. THE MOST SUCCESSFUL AND MOST DEPARTMENT OF LITERATURE 76. 60 percent.of CommercialArt Workis done by PROGRESSIVE COLLEGE IN THE WORLD " Free Lance Artists," who dotheir workat home and sell it to the highest bidders.Many IF YOU ATTEND TO THIS NOW, IT MAY MAKE A WONDERFUL DIFFERENCE TO YOUR FUTURE Commercial Artists draw " retaining fees "from various sources,others prefer to work full-time COUPON CUT THIS OUT employment or partnership arrangement. We teach you not only how to draw what is wanted, but how tomake buyerswant what you draw. To Dept. 76, THE BENNETT COLLEGE, LTD., SHEFFIELD Many of our students who originally took up Please send me (free of charge) Commercial Art as a hobby have since turned Particulars of it into a full-time paying profession with studio Your private advice about and staff of assistant artists; there is no limit to (Cross out line which does not apply) the possibilities. Let ussend full particulars for a FREE TRIAL and detailsof ourcourse for your inspection. You willbe underno obligation PLEASE WRITE IN BLOCK LETTERS whatever. Name A;It-.CAN ART DEPT. 76. Address

CONDITIONS OF SALE AND SUPPLY.-Thisperiodical is sold subject tothefollowing conditions, namely, that it shall not, without the written consent of the publishersfirstgiven, be lent,resold, hired outor otherwisedisposed of by way of Tradeexceptat thefull retail priceof 8d.; and that it shall notbe lent,resold, hired out or otherwise disposed of ina mutilated condition or in anyunauthorised cover by way of Trade; oraffixed to or as part of any publicationor advertising, literary or pictorial matter whatsoever. November, 1940 NEWNES PRACTICAL MECHANICS 41 RAWLPLUG PRODUCTS

ARE BRITISH & BEST OM/ co w RAWLPLUG

ilotyto C.(exti oie41 yeah ttiseivx RAWLPLUG PLASTIC WOOD WO" Rawlplug Plastic Wood is a pliable material RAWLPLUG DUROFIX Jots which can be moulded and fashioned into 19:9Wiati Durofix resists heat and water, and is ready for instant any shape desired. Hardens when dry and use without first warming, as is necessary with most becomes exactlylikereal cements.It is colourless, and joins made with Durofix FUSE WIRE wood, when it can be cut, are almost invisible.There are hundreds of uses for Durofix in every home. Sold in tubes at 6d. and'- each. ,Rawlplug Fuse Wire costs 3d. stained, planed or painted. per card and is wound with Waterproof andweather- RAWLPLUG wire of 3 amperages :5 amp. ELECTRIC proof. Tubes at 6d. and'- ANHA VG Lighting, io amp. Heating, -4+ SOLDERING IRON 15 amp. Power. Always keep andintinsfrom 9d. RAWLPLUGS PIA STI C A de -luxeElectric a card near your fuse box. - upwards. SolderingIron. It'ssoeasyto make neat WOODappl, Keepshotinuse, permanent fixtures with Rawl- very economical, can plugs-withoutdamageto rust 'w rood Cv be used on A.G. or be sawnpainted walls or decorations.Every D.C. Suppliedin t4.7nrs'i,X thefollowingvolt- Rawlplug Outfit contains full 4;rrns forfixingany cracks ages,100-I 10,200- equipment RAWLPLUG TILE DRILLS ted 210,220-230,240- ordinary article to any rt74ocE.bws"r;tr: 250. Prices : I I '9 material. A Rawlplug Outfit PlOutC7,11.. The Rawlplug Tile Drill is a twist drill of very high with Standard Bit, or isindispensable toevery quality.It can be used for drilling holes in tiles, brick at12'3 with Pencil and soft stone, and can be resharpened very easily. Bit or Hatchet Bit. householder who takes a pride Very quiet and outstandingly efficient in use.Prices Guaranteedforsix in his home. Complete out- from ltd. to si t each.Sizes from - ,3,, " to,". months. fits,t 6, 3 6 or 5 6. THE RAWLPLUG COMPANY, LTD.,Cromwell Road, LONDON, S.W. 7 B258A

THE "FLUXITE QUINS" AT PLAY 11111111111111111111111111111111111111111111/11111111111111111111111111111111111111111111111111111111111111111111111111 r: "Double Ten," cried OH, A Dozen To with great glee. Choose From "All we need nowisjust twenty-three," Fullsizecharts, in- structions, wood and Said EH, "Yes, m'lad, allpartsfor such You'll need Fluxite b'gad, popular Galleons as

- "To put back those scores- " SantaMaria, " you'll agree." "GoldenHind, " "Bounty," etc. A fascinating pastime See that FLUXITEisalways by you inthe house garage workshop -- for any craftsman. wherever speedy soldering is needed.Used for 30 years in Government works and by leading engineers and manufacturers.Of ironmongersin tins, 4d., 8d., 14 and 2B. Ask to see the FLUXITE SMALL SPACE SOLDERING SET ---complete but substantial --complete with full instructions, 7 6.Write for Free Book on the ART OF " SOFT" SOLDERING and ask for Leaflet on CASE -HARDENING STEEL and TEMPERING TOOLS with FLUXITE. H 1161ES TO CYCLISTS Your wheels will NOT keep round and true unless the spokes are tied with fine wire at the crossings and SOLDERED.This makes a murk stroncer wheel.Il's simple-with FLUXITE-but IMPORTANT MODEL GALLEON SETS THE FLUXITE GUNis always These kits contain wood, ready to put Fluxite on the sol- Send for free parchment sails, dowelling dering job instantly.Alittle formasts,cord,guns, pressure places the right quan- illustrated list eyelets, deadeyes and all tity on the right spot and one woodtosizerequired charging lasts for ages. Price ready for shaping. You I,'6, or filled2/6. can't go wrong to their FLUXITE Ltd., Dept. P.M., Dragon construction.All useful Works, Bermondsey Street, S.E.I sizemodels. Complete kits from 3'6. ALL MECHANICS WILLHAVE Callat any Hobbies Branch in London, Glasgow, Bit mingham, Manchester, Leeds, Southampton, Shef- field,Hullorwrite direct to Hobbies, FLUXITE Ltd.,Dept. 70,Dere- ham, Norfolk.

IT SIMPLIFIES ALL SOLDERING 111111111111111111M11111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111Ille 42 NEWNES PRACTICAL MECHANICS November, 1940 E El This IMPORTANT GUIDE to SUCCESSFUL ENGINEERING CAREERS After months of intensive effort and researchwe are pleased toannouncethatthenew editionofourhandbook, "ENGINEERING OPPORTUNITIES," isnow out of the publishers' hands and ready for free distri- bution.Containing 208 pages of practical guidance, this book is, beyond argument, the finest and most complete handbook on Suc- cessful Engineering Careers ever compiled. It is a book that should be on the bookshelf of every person interested in engineering whatever his age, position or experience. The Handbook contains, among other intensely interestingmatter,detailsofB.Sc.,A.M.I.C.E., A.M.I.Mech.E., A.M.I.E.E., A.M.I.A.E., A.M.I.W.T., A.M.I.R.E., A.M.I.P.E., CIVIL SERVICE, and other important Engineering Examinations; outlines courses in all branches of CIVIL, MECHANICAL, ELEC. TRICAL, AUTOMOBILE,RADIO, TELEVISION, AERONAUTICAL and PRODUCTION ENGINEERING, DRAUGHTSMANSHIP, TRAC- ING, BUILDING, GOVERNMENT EMPLOYMENT, etc., and explains the unique advantages of our Employ- ment Department. WE DEFINITELY GUARANTEE "NO PASS NO FEE" -_-TEAR OFF HERE If you are earning less than £10 per week you I ji =COUPON cannot afford to miss reading "ENGINEERING / ToB.I.E.T., OPPORTUNITIES."In your own interests, we advise / 410a, SHAKESPEARE HOUSE, you to write (or forward the coupon) for your copy / /7, 18& 19, STRATFORD PLACE, of this enlightening guide to well -paid posts-/ LONDON, W.i. NOW. There is no cost or obligation ofany kind. Please forward, Free of cost or obligation of any kind, your 208 -page Handbook, "ENGINEERING BRITISH INSTITUTE OF OPPORTUNITIES." Nome

ENGINEERING TECHNOLOGY Address 410a, SHAKESPEARE HOUSE, 17,18 & 19, STRATFORD PLACE, LONDON,W.1 I

MEM MINI INN I November, 1940 NEWNES PRACTICAL MECHANICS

SUBSCR I PTION RATES Inland and Abroad 7s.6d.per annum.

Canada - 9s. per annum. Editorial and Advertisement Office: ' Practical PRACTICAL Mechanics," George Newnes, Ltd. Tower House, Southampton Street, Strand, W.C.2. 'Phone: Temple Bar 4363. Telegrams: Newnes, Rand, London. Registeredatthe G.P.O.fortransmissionoy Canadian Magazine Post. Copyright in all drawings, photographs, and ECHANICS articles published in "Practical Mechanics" Cwrng to the paper shortage TheCyclist is specificallyreserved throughoutthe temporarily incorporated countries signatory to the Berne Convention and the U.S.A. Reproductions or imitations Editor :F.J. CAMM of any of these are therefore expressly forbidden. VOL. VIII. NOVEMBER, 1940. No. 86

The Falling Bomb with the growing volume .)t smrations 1-HERE has been considerable dis- FAIR COMMENT and suggestions intendedtofurther Canada's war effort. The establishment Icussion in the newspapers concern- By the Editor ing bombs and shells.1VIost of these of this board by the Canadian Govern- arguments evince a complete lack ofbomb whilst climbing, in order to ensurement provides a means whereby ideas knowledge offirstprinciples. Forthat from a given distance his bomband inventions submitted by citizens of reaches the target. Canada and abroad can be carefully example, it is stated that if you hear the examined and promising proposals sub- whine of a falling bomb, then you are New Job comparatively safe from a directhit,Seeking a mitted to the proper authorities. In this 'THERE seems to be a common beliefcountrytheinventorislefttothe whilst another argument revolves round tortuous and discouraging system of the question as to how far must an Ithatthoseengaged in reserved aeroplane be from its target before itoccupations may not leave their presentwriting to various Government depart-, employment in order to find anotherments who take months to investigate releases a bomb or bombs.In the case the matter. of the falling bomb, may 1 inform myjob.This is not so, for there is no law The Government should or regulation which prevents a man fromimmediately form the ministry we have readers that they are by no means safe suggested. from a direct hit if they hear its whine.changing his employment.There is, It is quite possible for you to hear thehowever, the recent regulation whichA New Book bomb which hits you, and it is certainlyinsists that employers must only engage THERE has recently been published possible for you to hear a shell which hitsstaffthroughthelocalemployment from the offices of this journal an you. The argument seems to be that asexchanges; therefore, applications forimportant new book entitled " Gears the speed of sound is about 770 milesjobs can only be made through employ-and Gear Cutting." Itdealswith per hour at sea level, a shell fired from ament exchanges.Employers naturallytypes, cutting methods and terms, bevel gun cannot be heard because it travelsare raising objections to staff changesgears, worm gears, gear generation, gear- at a much higher speed than that ofwhen the Government is pressing themwheelforms,epicyclicgeartrains, sound; but a shellisin no differentto accelerate output, but equally a manmethods of mounting, measuring gears, category to a bomb, for its velocity willengaged on work which does not employhobs, end mills, generating cutters, the have considerably fallen by the time ithis abilities to the best advantage isload capacity of gears, the efficiency of lands, and itis even possible for itsentitled to seek and to take another job.gears, and useful formulx relatingto speed to be much less than that of aIn any case, the employer has no powergears.The book is well indexed, con- bomb dropped from an aeroplane. Ato retain a workman against his will.Iftains over 100 illustrations in half -tone bomb released from an aeroplane hasa man is engaged, say, on drilling, whenand line, and costs 5s., by post 5s. 6d., an initial velocity equal to that of theheiscapable of tool-making, heis from the Book Department, George aeroplane, but from the moment itisentitled to seek a job as a toolmaker forNewnes, Ltd., Tower House, South- released it is subject to the accelerationdrillingisunskilledworkandtheampton Street, Strand, London, W.C.2. to earth due to gravity, which, of course,country is more in need of toolmakers. is 32.2 ft. per second per second.Its Recent Publications speed in a horizontal direction is there-Inventions OTHER books recently issued from fore gradually dropping, and thus the LAST month 1 made the suggestion this office are the " Radio Engin- aeroplane whichreleasedthe bomb that the Government should form aeers' Vest Pocket Book," 3s. 6d., by post would pass over the target before theMinistry of Ideas and Inventions, which 3s.10d.;" DieselVehicles :Main- bomb hit it.Some of the newspaperwould act as a clearing house to investi-tenance, Operation and Repair," 5s., by articles have affectedto givefiguresgate ideas and inventions to further ourpost 5s. 6d.; " The Superhet Manual," indicating how far from its target anwar effort, to aid our export drive, and5s., by post 5s. 6d.; " 'The Short -Wave aeroplane would have to release its bombto help industry when peace returns. InManual," 5s., by post 5s. 6d. ; " Watches: from an altitude of, say, 10,000ft. andAmerica, of course, there is the MellonAdjustment and Repair," 6s., by post 20,000 ft. when flying at 200 miles perInstitute, which was formed in 1913 and6s.6d.;" Motor Car Principles and hour.These calculations pre -supposehas carried out investigation work forPractice," 3s. 6d., by post 4s.; " The that the aeroplane would be flying on athe inventor and put, through, practicalEngineers'Manual,"5s.,bypost horizontal keel, and thus the calcula-experiment, over. 400 inventions right5s.6d.;" Dictionary of Metals and tionsarenot only meaningless, butthat started in commerce wrong. TheyAlloys," 5s., by post 5s. 6d.; and the grossly inaccurate, for a pilot could putnow work in a building which is largernew edition of " Workshop Calcula- his aeroplane into a shallow dive,a than Buckingham Palace.Canada hastions, Tables and Formula," 3s. 6d., by steep dive, and could even release thejust formed an Inventions Board to dealpost 3s.10d. 44 NEWNES PRACTICAL MECHANICS November, 1940

Preparingfora raid. "Wellingtonleing"bombed- up" before skirting off for Germany.

Bombing by Aircraft The Technique of Bombing and Types of Bombing Planes Used by the R.A.F. and other Countries NIGHTLY, bombing 'planes of theflown across the Atlantic for use by theengines, has a larger wing -span than the R.A.F.attack Nazi GermanyR.A.F. This machine has a top speed of Blenheim " I and carries a crew of three. through her dockyards, munitionabout 260 m.p.h. and a ceiling of 28,000 ft.This machine was designed as a recon- works and oil dumps which they bomb withThree Browning guns are carried, one fittednaissance bomber and torpedo dropper. unfailing accuracy. Oxygen apparatus nowin the nose and the other two in the tail. The " Blenheims " are used as intercepter makes it possible for bombing airmen to fly fighters as well as bombers. at a great height whilst over enemy territoryBomber Types and the danger of being hit by A.A. fire is Other types of machine used extensively" Battleships " of the Air considerably minimised. Before consideringbytheR.A.F.aretheHandley -Page A number of new bombing 'planes will the actual bombing,letus studythe'' Harrow " heavy bomber with a top speedshortly be coming into service with the machines which carry out the work. Firstlyof 190 m.p.h., the Handley -Page " Hamp-R.A.F. which will provide a first-class shock there is the Vickers " Wellington " long-den " medium bomber with a. top speed offor the Germans. Although they are on the range bomber which was originally fitted265 m.p.h., and the Armstrong -Whitworthsecret list, it is learned that they are twice withtwo 980h.p.Bristol" Pegasus "" Whitley " bomber with a top speed ofas powerful in nearly every respect to those engines, but now these machines have been215 m.p.h. already in use. They are surprisingly fast given an even finer performance with new - NextcomesthecelebratedBristoldespite their huge size, and a pilot who has typeengines.Two liquid -cooledRolls-" Blenheim," of which therearethreehandled one stated that they can be heeled Royce " Merlins "-the type fitted in thetypes.The Bristol " Blenheim " Mark 1over on one wing tip in the air with almost famous Hurricane and Spitfire fighters-medium bomber, fitted with two 840 h.p.the ease of a Hurricane fighter. They will be replace the radial air-cooled types previouslyBristol " Mercury " engines, and capablecalled Britain'sbattleships of the air " fitted.Whilst the improved performanceof a top speed of 280 m.p.h. ;the Bristolandtheyarealmostimpregnableto figures are secret the several hundred extra"Blenheim" Mark IV long-rangefighterordinary defence fire. Whilst on the subject horsepower may be assumed to add con-bomber, which has a maximum speed ofof new bombers, America has been carrying siderably to the former speed of around 295m.p.h.andispowered ,withtwoout tests on the Wright Field at Dayton, 260 m.p.h.Itisheavily armed against900 h.p. Bristol " Mercury " engines, andOhio, with new giant four-engined strato- attack by fighter aircraft. the Bristol " Beaufort.." which is a modernsphere bombers which are said to be almost Anotherpopular typeistheU.S.A.successor to the " Blenheim." It is poweredimmune from present anti-aircraft defences. Lockheed Hudson bomber which has beenwith two1,065h.p.Bristol" Taurus "Although details are withheld by the United November, 1940 NEWNES PRACTICAL MECHANICS 45 States War Department, it is known thatThen the room is darkened, and slides areslowly into position through the safety -glass these bombers are designed to fly eight tothrown upon the screen,details of thewindow below him.He isin constant ten miles above the earth in the strato-pictures being pointed out by the Intelli-communication with the pilot, and the pilot sphere. gence Officer. Photographs may show an oilfollows his directions implicitly.Various The normaleffectiverangeofanti-refinery, an enemy aerodrome, a hydro-factors must then be calculated such as the aircraft gunsissaid by United Statesgenationplant,asectionof theKielheight and speed of the 'plane, wind, etc., military experts to be about 15,000 ft.,Canal or an enemy warship. All the men payand as soon as the target comes into the because the shell must be timed to explodethe utmost attention to what is being said,sights a button is pressed and the bomb within a small radius of the target for it to be forthedifference between success andor bombs released. A bombing 'plane can effective. Thesestratospherebombers,failure may hang upon what they are beingcarry nearly a ton of bombs and these are army officials declare, will be able to destroytold. Each pilot and navigator has alreadydistributed under the wings or on either side targets with deadly accuracy, even from thebeen supplied with a photograph of hisof the fuselage. A bomb falling from a 'plane higher ranges, because of the secret gyro-target, and on this he writes notes whichgathers terrific momentum as it descends, scope bomb sight. The new bombers will bemay help him later.At the end of theand a bomb of average size falling from a equipped with super -chargedaircabinsbriefing the Intelligence Officer asks forheight of 12,000 ft. would be travelling liet a which will enable the crews to stand thequestions. Some he can answer personally.speed of 700 m.p.h. when it hit the ground. thinner air without wearing cumbersomeOthers concern the practical side of the There are various methods of releasing individual oxygen masks.One of theseoperation and are answered by the Stationbombs, and if the target covers a consider- bombers has been known to reach a heightCommander, who has taken his place at theable area, the 'planes fly over it in formation of 36,000 ft. which is an official record forback of the room. Many points are dis-and on a given signal from the leader four-engined craft. cussed,includingpositionsofballoonrelease their bombs.This is known As barrages which might interfere with the" pattern bombing."Or again, they may The " Briefing Room " success of the operation.Thus, when thefly one behind the other and release their Before starting out to bomb an objectivecrews set out on their raid they do so withbombs as each one passes over the objective. the pilots and navigators of the 'planestheir natural confidence reinforced by theWe now come to dive-bombing and in this taking part in the raid visit the " briefingprecise and expert knowledge that has beencase the pilot Of the aircraft " aims " his room " which ispart of ' every bomberplaced at their disposal. machine at the target and releases his bombs command aerodrome.Here they sitin as he pulls out of the dive. Medium bombers rows, whilst in front of them are a table andOver the Objective are generally used for this last form of chair. On the wall behind the table is a Once the 'plane is over its objective, theattack. screen, and at the far end of the room is aman at the bomb sights comes into action. As will be seen from the illustrations magic lantern. As soon as the crews haveOn this man's calculations depends theaccompanying this article, there are different taken their places the Intelligence Officersuccess of the raid. Lying full length on thetypes of bombs used depending largely on mounts the platform and explains in greatfloor of the 'plane he adjusts his sightingthe importance of the objective. Incendiary detail the object of the forthcoming raid.apparatus and watches the objective comeor fire bombs for targets such as oil dumps,

INCEND/ARY BOMB OPERATES ON IMPACT SPINNER RELEA 355 PRIMING COMPOSITION SAFETY OF THERMITE DEVICE DURING FALL. CONTACT BOMB OF BOMB HAS LIGHT CASING STABILISING EXPLODES ON PINS IMPACT EXPLOSIVE CHARGE- APPROX2S r GROSS BODY OF WEIGHT MAGNESIUM ALLOY MAIN BC/RAI/NG AGENT STABILITY -IGNITER FINS -PERCUSSION OPERATED EXPLOSIVE FUSEorMAGNESIUM ALLOY CHARGE

ARMOUR PIERCING 30/148 HAS HEAVY CASING. PARACHUTE EXPLOSIVE z BOMB CHARGE DELAYED APPROX. 10% FAL L GREATEST EXPLOSIVE GROSS ENABLES POWER WHEN BOMB WEIGHT PLANE TO CONTACTS IN CLEAR VERTICAL POSITIC' EXPLOSIVE DE TONATORS- FIELD -

.090"e4"- , .0V

11414A

Various tapes of bomb, the use of whichdepends largely on the importance ofthe objectice 46 NEWNES PRACTICAL MECHANICS November, 1940 etc.. and the very large bombs are generally British Blenheim, a somewhat comparable used for important military objectives. type.An earlier type of Douglas, the DB-7, has much the same characteristics Defending the Bomber but a lower performance. Its wing span of All our bombing 'planes are heavily army! 60 ft. is about midway between that of the against attack from enemy fighter Bristol Blenheim and the Handley - aircraft which generally attack the Page " Hampden." Another good bomber from the rear. Thus itis U.S.A. bomber is the Glenn -Martin the tail gunner's job to keep an un 167-W whichwas used by the ceasing watch over the entire area French Air Force. Not so fast as the within his view to the rear of the new Douglas -315 m.p.h. is about aircraft, and to report any incident the maximum it can do-it is never- such as anti-aircraft fire from the theless a generally useful type, being ground and totakeimmediate designed not only for bombing, but todeal NIGH action with any hostile EXPLOSIVE also for fighting, reconnaissance and aircraft.. When thetailgunner CHARGE ground -attack work. enters the rear turret at the begin- STRIKER -- A new American bomber which ning of a raid, first he puts his OPERArtS oiv will soon be flying with the R.A.F. parachute handy, locks the turret 1mPAcr OP is the Boston bomber.It has a tri- doors and prepares for action. He cycle undercarriage and will be the then rotates his turret to see that t3ELEASING A CIO FROM first machine of this type to go into it is moving freely, sees to his guns CON TA 11114'R service with the R.A.F.It has a and sights, his lighting system and wheel in the nose instead of the tail spare bulbs, and checks his reserve 400 PRIMARY and the usual main landing wheels ammunition. He plugs in his inter- TA/NEP- CHARGE in the nacelles of the engines.The communication set and speaks to Boston requires only a short run to the captain; then, having seen that take off as it is permanently in the all is well, he settles down to keep ALLOY CASING -- take -off position when at rest. watch, marking each section of the WHICH ACID PENETRATES AC/0 CONTACT New German Bomber sky to right and left, above and EiY CCRROSIVk CAUSES IGNITION below, just as if it were a sector of ACTrON Or PP/MARY As shown in the table on this page the countryside. CE/ARE the most popular types of Nazi Once clear of the English coast bombers are the Dorniers, Heinkels he 'asks permission to fire- a short and Junkers.They have now pro- burst to try his guns. Soon the air- ARMOUR PIERCING duced new four-engined bombers craft will he over enemy territory HEAD which are believed to be Junkers where enemy fighters may be met, 89's. They are rather cumbersome, t hough in point of fact they seldom however, weighing 22/ tons, and trouble the bombers at night. their speed of 200 m.p.h. is rather But the big moment, the moment A delayed action bomb showing the timing mechanism. poor. It is doubtful whether these for which all the rear -gunner's training hasArmstrong - Whitworth Heinkel 111, 3 machines will be very successful as their prepared him and in which the rest of the Whitley, 1forward movable guns. petrol or oil consumption is very heavy, and crew will depend upon him-comes when an gun, 4 rear guns. their operational advantages are not very attacking aircraft approaches within rangeVickers Wellington, 1 .1 unkers 88, 3 gun of his powerful Browning guns.If the forward gun, 4 rearpositions. bomber is flying alone the rear gunner will guns. have to deal with the attack himself if it is made from the stern. But when a numberAmerican Bombers of bombers are flying in formation any America's new -type bombers include attackers would have to meet their con-a number of fast, medium-sized twin- centrated fire.In any case the rear gunnerengined types with a useful range. is, and always must be, ready for immediateSome are fitted with diving brakes and action. The accompanying table shows howother devices for close attack duty and famous British types compare in armamentare known as attack bombers. The with similar Nazi types. Douglas B-23 is an interesting example British Bombers. German, Bombers. of American bomber design.Fitted Handley -Page Hamp-Bernier 17, 2 fixedwith two Wright Cyclone engines it is den, 2 forward guns, guns,2 move-claimed to have a speed of 375 m.p.h. 4 rear guns. able guns. This is some 75 m.p.h. faster than the

/015 220 lb 6 fiOi lb 880/b /500 lb 3960;b

7'can be judged by comparison with the man and boy who are of average height. November, 1940 NEWNES PRACTICAL MECHANICS 47 marked. A new advanced type of long-range twin-engined dive -bomberisalsobeing made by the Henschel Co. These machines have been designed to carry only one bomb, weighing about a ton, their policy being apparently one of chancing all on one direct hit. Yet another new German raider which has lately made a fleeting appearance over Britain is a large, black, four-engined heavy bomber which bears a strong resemblance tothepre-warFolke-Wulf"Condor." Designed as a 26 -seat civil air liner the " Condor " is a low -wing cantilever mono- plane with a wing -span of 108 ft. and only a single rudder.The civil version of the " Condor " had four B.M.W. radial engines of about 720 h.p. each, giving it a maximum speed of nearly 230 m.p.h. It had a "ceiling" of roughly 22,000 ft., and with special fuel tanks the extreme range was just under 1,000 miles.Its carrying load, all in. was 4f tons. Italian Bombers Italy's best-known bombers are ofthe three-engined type. The Savoia-Marchetti 79 and 81 are examples, the SM.79, powered with engines of the Bristol" Pegasus " type, being the more successful. This air- craft, with a wing span of about 66 ft. and a top speed of 270 m.p.h., is roughly com- parable in size and speed with the British Putting the sting in the tail of the bomber twin-engined Hampden.Newer arethe twin-engmed Savoia-Marchetti 85 and 86,machine has a speed of about 260 m.p.h.,four guns.Most ofItaly's bombers are and the Fiat BR.20. Thelast-namedand besides carrying a useful load mountsmore lightly armed. A General Purpose Electro-Magnet A Magnet Weighing One Ton commercial magnet -steel tenincheslong and 3f inches in diameter. The cores are made of Permendur which is the best magnetic material known for high flux densities. They are tipped with pole -pieces held in place by large soft iron bolts which extend through the end plates and the centres of the cores. This makes it A powerful easy to change pole tips. Normally two sets electro-magnet are used ; one has 45 -degree conical tips for formagnetising producing highly concentrated magnetic magnets fields ;the other has the upper surface planed offflatfor magnetising horseshoe magnets and similar devices. Magnetic Flux Since the total magnetic flux produced is about 1,500,000 maxwells, it was necessary to protect the magnetiser coils from insula- THE introduction of new materials forcan be adjusted by a jack -screw whichtion breakdown which might result from the more powerfulpermanent magnetsmaintains the air gap within close limitshigh voltages induced when a rapid change has greatly increased the difficulty ofalthough the force of attraction between thein this flux occurs. Threefold protection is magnetising magnets made from them.poles of the magnetiser may be thousands ofprovided to cover all possible contingencies. Electro-magnets have been used as magnet-pounds for short gaps. In addition, the coilsLightning protectors, which operate if the isers for many years, but some of the recentmay be slid independently on skid plates tovoltage exceeds about 500 volts, are con- alloys resist magnetisation so stubbornlyentirely cover the air gap. Cap screws whichnected permanently across each coil. Surge that a more powerfulgeneralpurposeextend through slots in the base of the coilsvoltages are smoothed by connecting across electro-magnet than was available was neededare used to anchor them securely in anythe input to the magnetiser coils a large in the laboratories to magnetise them. desired position. varistor whose resistance decreases rapidly as the voltage increases.Finally the cur- The Coils Magnetising Bars rent through the magnetiser is controlled by To fill this need a very efficient electro The coils, which have 4,500 turns each,a variable series -resistance which permits magnet has been built.It has two coils,are designed for a 120 -volt circuit. They con-changing the current only in small amounts each fifteen inches in diameter, which aresume about 700 watts when connected inat a time. A dash -pot arrangement has mounted facing one another close togetherseries and 2,800 watts in parallelThebeen provided to limit the speed at which on large horizontal cores. Heavy soft ironseries connection provides 50,000 amperethe resistance -control handle may be moved. end plates resting on an even heavier ironturnsforcontinuous operation without The new magnetiser has been in daily use base plate are bolted to the ends of the coresrequiring forced cooling and as much assince its installation.Its high power and to complete the magnetic circuit. The entire100,000 amperes turns can be obtained withflexibility combine to make it a valuable magnet weighs about one ton. To permitthe coils in parallel. By utilising the fulladdition to the working tools of the Bell varying the air gap between the pole faces,capabilities of the magnetiser it is possiblelaboratories.Reproduced from " Bell Lab- one core with its coil and pole -piece assemblyto thoroughly magnetise bars of the hardestoratories Record." 48 NEWNES PRACTICAL MECHANICS November, 1940 feboat

Lightship and Lighthouse Safeguards of the Seas

Reserve Lantern withitslenses and prisms, aroundthe In recent types two electric lampsstationary lamp at fixed intervals, smooth- occupy the centre of the lantern. oneness and ease of motion being assured by THE purpose of the " traffic lights of the ocean roads isto facilitate peaceful navigation and prevent loss of lite.The natural adjunct to lighthouses and. lightships (and buoys) is the lifeboat, Oneof the mos, whosepurposeistosave shipwrecked interesting light persons. These havegained'added housesaround ow interest in the public eye by reason of un- toast.It was one of holy attentions paidtothem byNazi airmen. the first to be lighted Except in outward form there is slight byelectricity,and resemblance between the modern lighthouse its beamhas the and, say, the first that was set up on the stupendous power of Eddystone rocks.A dozen or so tallow seven million candles candles provideditsillumination. The The double sires, present structure (the fourth to be erected shown on theright there)cost£60,000, and its main light. can be heard far out 133 feet above the sea is visible at a distance to sea in foggy of 171 miles ; another light shows 40 feet weather. Note the below the main one. The manner in which screens and guards any lighthouse shows its flashes is distinctive to keep sea -birds off from all others, so that it may easily be the glasses recognised.Its main part, therefore, is the lantern.These differ in make but agree in having an arrangement of lenses and prisms whereby the light of the lamp instead of being diffused, is concentrated intobeing in reserve. II the lamp which isin reason of the fact that the hollow base of extremely powerful beams-four.iftheaction suddenly fails the reserve automatic-the lantern floats on mercury in a trough. lantern has that number of panels. ally replaces it.The heavy lantern revolvesThe turning is done by an electric motor served by a petrol engine and dynamo; a second generating set is in reserve in case of breakdown. Sound -waves increase the use- fulness of some lighthouses, especially during fog; a siren or diaphone actuated by com- pressed air is used in conjunction with the light -flash. The time lapse, countedin seconds, between flash and sound tells an observer out at sea the distance the light- house is from him-the light -flash being practicallyinstantaneouswhilstsound travels through air at about 1,100 feet per second. An underwater sound -signal may be sub- stituted for siren or diaphone, a bell or oscillator suspended in the° water sending out vibrations that can be picked up by any vesselwithinreasonabledistanceand equipped with the necessary underwater telephone or other pick-up.The velocity of sound in water is nearly a mile a second ; therefore, if five seconds elapse between the light -flash and receipt of the underwater sound thevessel's navigator knows the lighthouseis approximatelyfivemiles diStant. Some lighthouses are equipped with radio-teleplmny, which enables them o piek up messages from vessels in distress. Lighthouses - Lamps of unattended lighthouses auto- matically light up when visibility falls to a certainpoint, and extinguish themselves when thelighthas regained a definite A typical lightship They are anchored where the erection of a lighthouse is impossible strength.These are visitedfor overhaul November, 1940 NEWNES PRACTICAL MECHANICS 43 once every three months.A radio beaconthe safety of crew and passengers of 'planesling lamps with portable morsing switch are sometimes takes the place of a flashingflying across the Straits of Dover.Shecarried by electrically equipped boats.In light,automaticallytransmittingmorsebears the name Sir William Bilk -try, whosome, an oil -tank is located in the bows, signals which enable a navigator who maywas founder of the R.N.L.I. from which the wave -subduing hquid can be shrouded in dense fog to determine his be sprayed ; and a line -throwing gun with position relative to the wireless lighthouse.Steam Lifeboats a range of 100 yards can be fired from a The modern lightship, anchored where the Steam lifeboats appeared in1890, thetripod or from the shoulder.Fire -control erection of any kind of lighthouse is im-first at Harwich. Propulsion was by waterapparatus is also carried. possible, is equipped with lantern, diaphonedrawn in through an opening in the boat's fog signal, submarine oscillator,wireless,bottom at the rate of a ton a second by aLaunching Methois and has its own distinctive morse sign.powerful pump and discharged at the sides. Launching methods arelargely deter- Two of the most famous lightships markIt had a speed of 9 knots. Only a few wentmined by the nature of the shore from which the treacherous Goodwin Sands and theinto service, and the last was withdrawnthe lifeboat operates.If a special slipway Thames -mouth Nore Sand :their hardyin 1928. A lifeboat was .first equipped withis used the boat slides down by its own crews have seen rather more than their sharea petrol engine in 1904, this being supple-weight. To enable it to be hauled up again of war -time activity. Lightships,light-mentary to sails and oars. The experimentafter use, the boat is furnished with chains houses and buoys (the latter each anchoredresulted,five years later,in a lifeboatwhich pass through holes in the keel, forward in its own spot and telling its own storyspecially designed for petrol engine pro-and aft.Hauling cable is attached to these automatically by light or bell or whistle)pulsion.In 1923 the first twin-screw boatchains and power is supplied by a winch around the English and Welsh coasts are theappeared, but not until 12 years later wasat the top of the slipway.For launching responsibility, mainly, of Trinity House. thefirstpowered lifeboatwithout anyfrom a beach, portable rollers are sometimes sailing gear put into service. used, the lifeboat being pushed along and Lifeboats Apart from theoutsizeSirWilliaminto the water with long poles. A wheeled Lifeboatshavebeen improvedtoaHillary, power ranges now between 12 h.p.carriage hauled by a motor -tractor may be similar extent, those carried by some bigpetrol engines and twin 40 h.p.dieselused to transport the boat to the launching vessels being equipped with a safety deviceengines.Machinery continues in operationsite ; the tractor is then removed and the to facilitate launching.This consists ofeven when the engine -room is flooded, andlaunch effected by man -hauling on ropes two or more semi -circular steel skates orin all cases is controlled from the deck.which, attached to hooks on either side of narrow plates clamped to that side of theIn the self-righting boats a mercury typethe boat's sternpost, pass through sheaves

(Left) A self-righting lifeboat of the light type for launching off the beach, 35 ft. 6 in. long, weighing 61 tons and driven by one 35 h.p. engine.(Right) Two 40 h p. diesel engines in the engine room of a lifeboat. lifeboat which is nearer the ship's side; thecapsizing switch automatically cuts off theat the fore -end of the wheeled carriage and skate extends upwards from the lifeboat'sfuel supply and stops the engine when thethen back to shore. Where damage is likely keel, and shock absorbers separate the skateboat assumes a tilt of about 60 degrees ;to occur to propellers through contact with from the boat. This device enables the life-theengineisrestartedagainwithoutshingle or rock they are protected with boat, when being lowered, to slide smoothlydifficulty when the boat is right way upshrouds. down the ship's side however acutely theagain and it is seen that none of the crew big vessel may be canted over (in thehave been pitched out.This type. afterLifeboat Construction opposite direction). As soon as the lifeboat,having turned completely over, will right Construction is of wood.Steel has been with its full complement, is launched theitself and get rid of all water in 25 seconds.tried, but experience proved that wood will clamping screws are undone and the skatesThe other type, which cannot self -right, istakeseverepunishmentunderwhich pulled inboard or allowed to sink.Theprovided with greater buoyancy, stabilitynecessarily thin steel plates would collapse. world's largest liner, the Queen Elizabeth,and speed.Danger of total flooding isSteel is, however, used for bulkheads in the gross tonnage 85,000, with 14 decks andreduced by water -tight compartments, andlarger boats.About 8 tons of carefully accommodation for 2,326 passengers and abuoyancy is increased by air -cases rangingselected and worked timber go into a 46 -foot crew of 1,235, has motor lifeboats, any onein number between 70 and 160.Thesecabin lifeboat of the Watson type, which of which will accommodate more passengerswould keep the boat afloat in the unlikelyweighs IS tons without the crew. The total than the first of the Cunard ships, theevent of all the water -tight compartmentsis accounted for as follows : 12 cwt. of Britannia, ever carried on any one voyage.being smashed open.As fast as water isBritish oak, for the stem and stern ;1 ton The lifeboats which operate around theshipped, in normal circumstances, it is dis-8 cwt. of Canadian rock elm for the frame- 5,000 miles of coast of Great Britain andcharged through one-way valves in the sideswork; 5 tons of Honduras mahogany for Ireland are provided and maintained byabove the water -tight deck ;a boat filleddeck and planking (or skin) ; 6 cwt. of Burma the Royal National Lifeboat Institution, ato the thwarts will empty herself in12 teak for the keel; 14 cwt. of Canadian white charitablesocietysolelydependent onseconds. deal or Columbian red cedar for the air - voluntary contributions. The R.N.L.I. has The use of wireless for intercommunica- cases.To get those finished quantities 194 more than 130 motor lifeboats, with petroltion between lifeboat and shore -station, istons of wood in the rough have to be or diesel engines, and twin or single screws.at present restricted, for technical reasons,handled.Costs are high, varying from The largest, and the most powerful in theto boats with cabins.These have radio-£3,700 for a 32 -foot surf motor lifeboat to world, has two engines each of 375 h.p. andtelephony, with the exception of one which£11,000 for a 51 -foot cabin motor type. a speed of 17-18 knots; she is 64 feet byhas wireless telegraphy. Portable and sub-Engines range between £400 for a 12-h.p. 14 feet and was built specially to guardmersible searchlights and masthead signal -petrol to £1,300 for a 40-h.p. diesel engine. 50 NEWNES PRACTICAL MECHANICS November, 1940

MINESWEEPING S HIP

TOWLINE DEPTH ADJUSTED ONCAPSTAN

PARAVANE 9ELOW SURFACE4w,' WHEN A MINE FOULS PARAVANE, IT IS DRAGGED ALONG THECABLE 8 CUT BY THE SAWING MOTION, OR SEVERED BY CUTTER ON THE . GUTTER PARAVANE. TOWING SLEEVE

FREED MINES FLOAT TO THE STABILISERS SURFACEdARE DESTROYED BY RIFLE FIRE. TOWLINE LOWERED TO PARAVANE VARYING DEPTH BY TRAILING PARAVANES ARE KEPT PASSING OVER SLIDIN s HOE AWAY FROM SIDES OF SHIP BY FINS

How paravanes are used by minesweepers to cut the cables anchoring German mines.They are also used to protect the sweeper from accidentaliy hitting a mine. Safeguarding theVinesweeper The Use of ParavanesinMinesweeping THE risk run by a minesweeper whenwater, and is lowered to the lowest part ofshoe." The " chains " pass through special operating in a minefield is consider-the stem when the paravanes are runningholes in the forefoot of the sweeper, and able, and in order to minimise -theclear of the sweeper. If it is desired to takethey can be hove up and down by means of danger of the trawler striking a mine, special inthe paravanes the" shoe "israiseda capstan types of sweep are used.Although thereagain,to enable the towing wire to be are various methods of sweeping, only one iscaught in a snatch -hook attached to the:Paravane Davits dealt with in this article and that is high-wire which is used for hauling in and hoisting The paravanes arecarried onspecial speed sweeping. the paravane. " paravane davits " when not in use, or With high-speed sweeping the sweeper is If desired, the " point of tow " of the_they can be stowed on special slips. They protected to a very considerable extent, asparavanes may be attached to " paravaneare kept constantly ready for use, however, the sweep is towed from the bows insteadchains " as an alternative to the " towingin time of war, with their towing irvs of the stern which is usual with other types of sweep. It consists of paravanes towed on OECK OF FORECASTLE either side of the trawler, at, the end of a WINCH speciallystrong,lightwiresweep,or PARAVANE " towing wire." The paravane is made of metal, is buoyant and is similar in shape to a torpedo. Running at right angles to its length is a metal plane which is weighted SEA LEVEL at one end and is made buoyant at the other. The paravane is inclined to one side CoTTER by means of this metal plane, so that when TOWING WIRE it is pulled through the water, it tends to ROINT OF TOW/ run away from the ship that is towing it. (Tom SHOE)

Inside the Paravane Fig. I.-Showing how paravanes are towed and how A hydrostatic valve is incorporated inside they fend off mines and sweep them. A. Towing shoe the body of the paravane which in turn raised out of the water when paravanes are not in use. MOORING ROPE controls a horizontal rudder, and this keeps B. Towing shoe lowered into position at the lowest SIN 1

whilst at the same time, the " Uclamps about tobe mentioned afford a better A Novel Bending Toolpurchase ; a plain strip of wood is not, after considering this point, advisable. Constructional Detailsof aSimple Press Side Clamps Owing to the slight " givewhich may for Bending Sheet Copper and Aluminium be apparent at the ends of the jaws after clamping the metal, two " U " clamps are AVERY necessary tool for the homepieces of oak, carefully planed, these pieCesprovided to ensure a more even distribution constructor is a bending vice, that willbeing positioned on the bench runner withof pressure for acute bends, and the method provide clean flexures for the morethe vice in the most convenient place, thenadopted is clearly defined.Fairly heavy pliable metals-copper, aluminium, brass andscrewed down with three well countersunkgauge mild steel is used for each clamp with certain soft steel of reasonably light gauge.screws to each side. the edges slightly rounded tofacilitate The simple bending vice, shown in the Both jaws " Aand " B " are of well -fitment over the tapered edges of the jaw. accompanying illustration,will be foundseasoned oak, the intermediate strip, which It will be noticed that these " t" pieces particularly useful for the purpose, espec-was necessary to bring the width up to theslide into slots provided between The jaw ially where an ordinary wood workers' vicedesired limit of the movement, being ofand the bench, thus when the metal to be is not available.* good quality" plywood.This " padding "bent is positioned, it only remains for the end clamps to be tapped over the jaw, after pressing down the handle. If itis desired that the handle of the PLY WOOD press be kept down under pressurein BASE OF EMBOSSING PRESS PA5DTORI,n,1 RECESSED IN BACK. STRIP uuAnNlnxna. addition to the end clamps, a simple method is to attach a strong spring to the bench,

AD'Ef a suitable hook being provided which will WELL SQUARED '.14101. 111111PRESSBASE HARD OAK JAWS conveniently slip over the thin part of the FainS handle; this consideration, however, is not "." MILO STEEL END CLAMP included in the illustration, as the essential features only are dealt with in regard to the SEE TEXT BENCH adaptation of the embossing press. RUNNER

MOVING JAWS 'EXTENSION IN PRESS HEAD WIDTH OF JAWS FIXING SCREWS SLIGHT TAPER .1/ BOOKS tvorth SEE INSET TEXT LIMIT OF /////1-` METAL READING

EMBOSSING PRESS WITH PLATES REMOVED

HANDLE REQUIRES NO HOLDIN p DOWN Hobbies Handbook for 1941 WHEN JAWS ARE CLAMPED have just received a copy of Hobbies WEhandbook for 1941, which is packed General arrangement of a simple bending vice. full of useful reading matter for the handy- man and home craftsman.It describes When deciding upon a suitable method ofstrip as itis called here, also serves thedozens of ways in which you can spend construction,it was found that an oldpurpose of reinforcing the fixture of the pressyour spare time profitably. A design chart embossingpressprovidedthedesiredbase to the bench, since after fixing down thepriced at is. 6d. is given away free with the pressure.When obtaining one of thesebase and each section of " A as mentioned,handbook. The handbook tells you how to embossers from a second-hand dealer, andthe extra screws necessary for the paddingmake all kinds of models in wood-battle- after a preliminary examination, it wasstrip should be long enough to pass rightships, model planes, guns, bridges, railway found that the removal of the name platethrough the jaw to the bench runner. stations, etc., or practical pieces of work fixing screws was all that was required in The jaw " B " is fitted after the assemblysuch as cigarette boxes, table lamps, furni- the way of alteration. just described, as the holes in the press headture, with large complete pattern sheets for With both plates removed it was thenthrough which the fixing screws pass, are inall necessary parts. As well as containing noted that the maximum movement of thedirect line, and can be conveniently used-numerous instructive articles on woodwork, press head was 3/16 in., thus by allowingat least in this particular case-for insertinga complete range of fretwork tools and wood 1/8 in. gap between the proposedwooden,a screwdriver to fix the padding strip andare listed. The Handbook costs 6d. jaws " c 'the correct thickness of bothbase screws; this will be clear on referring to jaws and the intermediate padding stripthe illustration. " GlossaryofAeronautical Terms."By "a," "b" and "d" could soon be determined. The inset diagram shows how an exten- Douglas H. Wilson.Price 3s. 6d..112 Itisnot intendedthatgauges abovesion "W1 " may be made in the width pages.236 illustrations.Published by 16 S.W.G. be handled by this vice, so" W " if deeperbending is required to that Geo. Newnes, Ltd., Tower House, Strand, 1/8 in.is ample for adjusting the metaldepicted by the limits in the illustration, the W.C.2. along the bending lines. pattern of theparticularpresscasting A handy dictionary of terms based on the determining the limit to :the edge of thenomenclatureadoptedbytheBritish Oak Jaws metal. Standards Institution and recognised by the To provide a flush mounting, the base of By cutting away the jaw " B " to bridgeleadingauthorities.The bookiswell the press is recessed as depicted, conse-the press as depicted, a greater degree ofillustrated and includes identification sil- quently the jaw " A " is made up with tworigidity lis given to the ends of this jaw,houettes of German and Italian aircraft. 52 NEWNES PRACTICAL MECHANICS November, 1940 trical equipment in refineries,Shop Lighting as well as reducing corrosion. A "green acid"-a sulphuricCHOPKEEPERS hope that they will be acid product-isbubbled0 allowed to use a new modified form of throughwater,saidthedisplay window lighting this winter. Light- engineers, forming largeing engineers have been trying to perfect a quantities of foam,whichsimple new device.It will be an im- absorbs thesulphuric acidprovedversion of the device used last mists. winter. Spin- Proof A MERICAN aircraftfac-Powerful New Tank rA tones are now producingAANEW British tank which is now in use a new light aeroplane which will be one of the most formidable we is of unusual design. Crackhave yet put into the field against the American pilot found thatenemy.It combines speed with the maxi- whenputtingtheplanemum of armour, and armament capable of through its paces it was im-piercingtheprotectiveshieldsof any possible to put it into a tailvehicle which the enemy has yet put into spin owing to its phenomenalthe field.The successful combination of "air -worthiness." The ma-these qualitiesisthe result of years of chine isfittedwith super -experiment. THE MONTH OF SCIENCE , . safety landinggearandNew Secret Defence -Showing ien pus acnutes being released simultaneously en the re -opening extra -simplified controls.It of the popular parachute jump at the New York World's Fair. More than is called the Ercoupe, and SIR ARCHIBALD SINCLAIR, the Air half a million persons experienced the thrill of the 250 -ft. drop last season. will, in the opinion of the Minister,recently referred to a new U.S. Civil Aeronautics Authority, greatlysecret defence against bombers. He said : Miniature Barrage Balloons speed up the " education " of novice pilots" We are working hard at the solution of AN inventor claims that it is now possibleand help to eliminate many private flyingthe problem of dealing with enemy night to have barrage balloons at negligiblefatalities. bombers and are making progress.'The cost.His idea is to coat a very -thin wire system, which was not in use when war with chromium crystals so that it will cut began, has succeededinbringing down into steel.One metre of hydrogen will be Feat bombersincertaincircumstances ;for -capable of holding up 1,000 ft. of the wife, FOUR huge water wheels, which wereinstance, in the defence of small sites.It is and calculations have shown that its tensile installedin 1832 for driving the millnot possible to hint at the nature of the strength is such. that it will easily stand upmachinery, are still in daily use at the linendevice, but it can be said that it is simple to an aeroplane travelling at 200 m.p.h. Inworks of James Finlay & Co., Ltd., Perth-and not costly to manufacture or use.It this way the barrage balloon can be reducedshire.It was considered a great engineeringdoes not need a large number of men to considerably in size and the barrage can befeat when the water wheels were installed.operate it.It is neither a balloon, a gun, extended indefinitely at small cost. and they have given continuous service fornor a ray. When the device is developed, more than one hundred years without needthe defence of London will be enormously This Castor Oil Is Nice for any repairs.Each wheel is 36 ft.instrengthened. APANishow using a castor oil thatdiameter and develops 75 h.p. at two revolu- Jfizzes. The oil, which is quite pleasant totions a minute, the source of power beingA Pilotless Plane drink, has citric acid and bicarbonate oftaken from the water from the River Teith. soda added to it.When the concoction is ACCORDING to an American inventor, mixed with water and stirred, it effervesces, Dr. Lee de Foresri, a pilotless " tele- thus masking the taste of the castor oil. "All -Purpose" Gun vision torpedo " plane may be completed TWO of the latest weapons of war pro-within a year.He states that the plane World's Biggest Aeroplane ducedinthe United States are thecould be made from inexpensive plastics largest aeroplane in the world is all-purpose " gun and the Garand rifle.and would require no armour, as it would be THEnow nearing completion at the DouglasThe feature of the " all-purpose " gun isa robot -machine.The flightcouldbe Aircraft works, America. Itis a four-that it can fire anything from tear gas anddirected by radio from a mother ship ten engined American bomber with a 210 -ft.parachute flare shells to 1 -lb. fragmentationmiles or more away. wing span, and its 8,000-h.p. engines willbombs. The Garand rifle is considered one Television cameras could be placed in give it a range of 7,000 miles. of the finest infantry rifles in the world andthe nose of the plane, and a television is capable of firing 30 shots a minute. transmittercouldsendpicturesof the terrain below to a ground base or to the "Heavy Water" mother ship,where operators would be HEAVY water," a curious liquid which New Incendiary Weapon The army " was produced a few years ago from able to manoeuvre the plane. heavy hydrogen, -is still the subject ofA CCORDING to the daily papers, theauthorities who are at present testing the numerous experiments. Its chief drawback,TAR.A.F. are using a form of incendiaryplane, say that it- could also act as a robot however, is that it is very costly to mane-weapon which can be described as a self -bomber.Itis estimated that the plane facture and works out at 6d. a drop. igniting leaf.It is designed to set fire, forwould cost between £250 and £300. example, to military stores standing in the A Use for Bubbles open, to an arsenal or ammunition factory.Bomb -proof Tunnels AMERICA'S oil industry has found ato a dump of engineers' stores in the field, use for bubbles.They are being madeand other similar objectives.Our planesASUGGESTION has been made as- to to order by a new process to prevent forma-drop them on objectives during the night whether, in the opinion of competent tion of a destructive sulphuric acid mist inand when the rays of the sun fall on themengineers, deep bomb -proof tunnels could refineries.Two Chicago engineers, D. W.they are ignited. The accusation made bybe dug in London for the whole population Bransky and F. F. Diwoky, told an Ameri-the Germans that the leaves cause poisoningof 6,000,000 for a total cost of £120,000,000; can Petroleum Institute meeting at Fortis false.The leaf is not poisonous, but itthat such tunnels could be used after the Worth, Texas, recently, that manufacturehandled, it would cause burns just as everywar forrelief of traffic congestionand is abolishing the need for expensive elec-other incendiary bomb would do. whether,inviewofthe Government's November, 1940 NEWNES PRACTICAL MECHANICS 53 declared opinion that the war will last threeheated, the professor said, and the trans-intended for use in the rubber dinghy used years, the Home Secretary will give theformation was completed in about an 'hour.by pilots who have had to leave their necessary instructionsforthis work to machines when over the sea.This trans- be put in hand forthwith. Self-sealing Petrol Tanks mitter does not appear to be a regular part of the equipment of the Nazi planes, but is 500m.p.h. Fighter SOMEWHERE inEngland is a testingprobably carried only when an important ANEW twin-engined interceptor plane, ground where technical experts of theNazi official is being flown. FA the Lockheed P38, has successfullyAir Ministry study the progress made in undergone testsat Burbank, California.German aviation. As Nazi planes are shotProbing Nazi Radio Secrets The plane flew down the coast at 350 m.p.h.,down in this country, they are carefullyIT is evident that the radio technicians with its engines only opened out to halfstudied by these experts, who look for any associated with the R.A.F. do not take throttle, and it is expected that the aero-outstanding featureintheir design.Of plane will be able to attain a speed ofgreat interestis the German self-sealinganything for granted when examining and 500 m.p.h.Itlands and takes . off atpetrol tank. Although they are very heavy,testing the equipment of shot -down German weighing 41- lbs. per square foot of tankplanes.At a certain experimental estab- 100 m.p.h., and can climb 4,000 ft. in one lishment there is a very large dossier con- minute. The machine is armed with awall, they are extremely effective. The walls of the tank are built up of severaltaining complete specification of the radio 36 -millimetre cannon in the nose, and is equipment. Not onlydoesthis equipped with numerous machine-guns. layers.The outside covering of the tank give consists of a thick coating of vulcanisedcompletespecifications,testdataand Mobile Garages rubber, followed by a layer of thin treatedcircuit diagrams,but also valve curves CANADIAN divisionsinthe fieldarerubber, then a layer of leather, a covering ofand the most minute detail of every part nowbeingequippedwithmobilethick pure rubber, and finally an inner wallof the equipment. Standardised Valves AX interestingfactconcerning the FA standard receiving equipment fitted to IN THE WORLD most of the German planes is that H.F. pentode valves are used exclusively; every valve in the set is interchangeable with any of the others: The valves have side contact bases and top cap; they are fitted in an AND INVENTION inverted position and are held firmly in garages which are outfitted as efficientlyof fibre.The whole is held firm by a criss-place. To withdraw them a small knob is and completely as any modern city garage.cross of internal fibre stiffeners. When thescrewed into a tapped hole in the plastic - They are converted motor transport lorries,tankispunctured, the petrol melts thematerial base.The valves are very small and each one is fitted with its own electricalthick pure rubber and seals the hole. and bear some resemblance to " acorns," plant, to operate electric grinders, drills, although being somewhat larger. refacers, lathes, brake servicing equipment,Automatic S 0 S andothertools. Lubrication,battery ANOTHER interesting " findin one ofAn " Invasion" Boat service and overhauling facilities, including theshot -downNazi planesisaTHEChris-Craft Corporation in Algonac, theboringof cylinders,thefittingofcomplete radio transmitter mounted in a Michigan, announce that a new spoon - pistons, valve grinding and welding arewaterproof metal container. The containershaped30 -ft.boat,builtspeciallyfor provided in this modern garage on wheels.holds a small transmitter, the necessarylanding troops from battleships, has been Alltoolsrequiredhave beenspeciallybatteries and a motor which automaticallydelivered to the United States Navy. designed with a view to portability and" keys " the morse signal, S 0 S, S 0 S S. .. The vessel carries a maximum load of are part of each lorry unit. when the transmitter is switched on. 35 men and can be taken into water only The transmitter can be used in conjunc-six inches deep to effect a landing. When tion with a form of " umbrella " aerialthe boat leaves theshore, two flipper Air Conditioners fitted on a long, thin mast, or with a kiteappendages are lowered into the water and DEVICE thatisbecomingratheraerial, the line for which is carried on a reelthe propellers thrown into reverse. The Apopular in America is an air-condition-inside the container. backwash from the propellers strikes the ing unit.This is a self-contained device It is presumed that this transmitter isflippers and lifts the craft off the bottom. made to fit on a window -sill or table and provides de -humidified, fresh filtered air in summer and fresh filtered air (warm) and ventilation in winter. New Type of Organ THEphoto -electriccellhasawide variety of applications.It can be used for burglar alarms, shop -window lighting, operation of electric signs, timing of races, etc. This little device has now been adapted in a new type of electric organ. The organ bas been devised based on the use of " synthetic "wave forms imprinted on rotating discs, which interrupt light beams in photo -cell circuits for each wave form. An almost illimitable range of tonesis, therefore, made available. Laboratory Coal and Oil ACCORDINGtoDr.Ernest Berl, Research Professor at the Carnegie Institute of Technology, coal and oil can be made in one hour in a laboratory. Dr. Berl told the American Chemical Society in Detroit that he had discovered a process whereby coals, asphalts, and oils, having exactly the same properties as their natural counterparts, could be made from grass, An American "war truck."These armoured cars are equipped with two 6 -in. anti-tank guns leaves, seaweed, wood, cornstalks, and other and powerful machine-guns. The guns are in a 360 -degree moveable turret.The arms that look materials containing carbohydrates. like vacuum cleaners can be lowered to the ground to take up gun recoil. The trucks have undergone The substance is placed under pressure extensive tests and are powered by a marine diesel engine. They have been drawn at speeds up to with limestone and similar materials and 65 m.p.h. by their 12 war wheels 54 NEWNES PRACTICAL MECHANICS November, 1940 Using the uIti-Purpose Tool ASCREW cutting dieis included inFurther Details Regarding the Use of the Juneero Tool which each Juneero Set to enable you to cut threads on the rod.Place the was described in Last Month's Issue clamp plate in position as shown in the illus- tration-this acts as a vice to hold the red to Whenimitatingwroughtironworkthe he threaded-nextinsert the rodto be decorative effects of the old smiths can be threaded and tighten up the nut so that the obtained by cutting the ends of the strip rod is held in a tight grip. Insert the die on in the form of spear points and up -setting the end of the rod, hold the die perfectly a rib along the point by the aid of the bend- square and rotate it slowly in a clockwise ing die. direction.It will gradually feed itself on the rod. The Curve and Scroll Tool Before commencing to cut the thread drip The Juneero Patent Curve and Scroll a little lubricating oil on the end of the rod Tool enables accurate curves and scrolls to that is to have the screw cut on it.This be bent from rod or' fiat strip.The tool will lubricate the die, causing it to cut more which is shown in the sketch provides for five freely and to last, longer. After rotating the diameters. This is invaluable when making die three or four complete turns in a clock- certain objects, such as clips for the repair wisedirection.twistitintheopposite of water hose, which must be made to a direction for a quarter to half a turn to definite size. The. tool is quite simple to use. Just feed the end of the strip or rod into the guide plate as shown, and hold it with the fingers of one hand. NVith the other band, force it round the circular face of the tool. If it is required to form more than a semi- circle,first form a half circle, and then feed as much of the formed portion as necessary through the guide plate. Continue forming the rest of the curve with the fingers as before. After a little practice you will be Cutting rod.Insert rod in sleeve as shown just above the able to form circles, arcs, scrolls. etc., in an bending die.Raise lever as if operating the bending die expert manner. is pushed through the hole until the edgeImportant of the hole comes opposite the part of the On no account should metal strip or rod rod that it is intended to bend. This can beother than that supplied with the .Juneero marked on the rod or located by the gauge bar.The rod is bent by pulling itin the requisite direction with the fingers. Theillustrationinthefirstcolumn shows the method of bending the strip. Here again the position of the bend may The Jun- be marked on thestripor located by eero Patent the gauge bar. Before bending it is desirable Curve and to smear a little oil on both sides of the stripScroll Tool in the region of the bend. This lubricates it and facilitates the bending operation. Bending strip.To open jaws of bending die, pull lever To bend the strip press the handle right right Iowa towards the front.Insert strip in required downtowards the front of the tool, i.e., the position, then raise lever until correct angle is obtained side remote from the bending die.This

break up the chips of metal that are beingopens the jaws to their full extent. Insertset he cut, bent or punched on the Juneero out off the rod. The screwing die shouldthe strip and pull the handle up to bend the tooLIf metal that is thicker, of a harder be cleaned after use by blowing the chipsmetal. The handle should not be jerked uptemper, or otherwise unsuitable is used, the out of the holes. sharply but pulled with an even steadytool may he irreparably damaged. Bending and Forming motion. Make sure to insert the metal as Four holes are drilled at the corners of At the back of the Juneero tool is thefar as it will go into the jaws of the tool.the wooden base on which the toolis bending die for bending strip, and below itSight the strip along the gauge bar tomounted. These enable it to he screwed or isa small hole whichisusedtoeffectensure that it is parallel with the bar andbolted firmly on to the work bench and it sharp bends in the rod. The rod to be bentthat it is truly at right angles With the strip.is recommended than this is done.

(Left) Bending rod, Insertthe rodin thehole below the bending die, to the position where angle is required, grip firmly in the right bondand bend roundas shown. (Right) The method of thread- ing rod November, 1940 NEWNES PRACTICAL MECHANICS 55 The Fascination and Problems of Speed What will be theultimate Speed reached by Man ?

4:1

Road transport ancient and modern Stephenson's"Rocket" compared witha modern streamlined train THE man who set the first log rolling startedthecrazeformechanical relatively low one (astronomically speaking) speed. From theroughlogthe of about 50 miles per second. smooth roller developed, and from that the wheel. No name or date or country is Light Waves attached to the inventor of the wheel, but The outer stars of the Milky Way are whoever he was he let loose a chain of moving at the rate cf 150 miles per second, consequences of which he could not be and the light -waves which come to us from expected to have the foggiest notion. Taking some of the more distant nebula, started on only one use of the wheel-the facilitation their journey through space before human of travel-its slow but steady development life appeared on the Earth, the era of enabled mankind to reach speeds which giganticreptiles. Those nebulaare pleased him exceedingly. With horse and 40,000,000 parsecs from us.One parsec wheeled vehicle of one kind or another he equals 19,150,000,000,000 miles, dr 3.26 increased his rate of progression over the light-years; a light-year(0.3069 parsec) ground to round about 10 miles per hour. is the distance which light travels in a year, A sail enabled him to do the same for thatis,5,880,000,000,000 miles.Speeds himself on the water. For several hundreds and distances of that order are difficult to of years that remained his maximum. Then grasp ;it is easier to visualise their meaning he learned how to dispense with the horse- if we convert them into terms of, say, and his sail-and harness horse -power to railway travel.A train travelling without his needs. Stephenson's famous locomotive, interruption at 60 m.p.h. would (if such a the "Rocket,"did 35 m.p.h., and the journey were possible) encircle the world in world (or that part of it which was inter- something under 20 days; the journey from ested) was astonished. Earth to the Sun would occupy 177 years ; In July of this year an English test - to the nearest star, 40,000,000 years. pilot took his aeroplane into a power dive Comparedwiththetimetakento at 600 m.p.h. complete those suppositious journeys the train's speed of 60 m.p.h. seems trivial. Speed of Sound The same speed would get you from London That's getting rather close to the speed to Brighton in an hour-which at once of sound, which is nearly 770 m.p.h.If makes it seem rather considerable.It's all and when an aeroplane manages to exceed a matter of comparison. Which brings us that speed it will outrace the noise of its to a seeming paradox : that an object can engines and, incidentally,involveitself be both at rest and in motion. A fixed with many interesting new constructional object on the Earth's surface-a house-is problems, and others connected with Time not moving relative to the ground it stands and Space. As we extend our incursions on. But relative to the sun it is moving all into the realms of -really high speed the the time at tremendous speed !The same question as to whether there is any limit to thing can be said,of course, about a it-so far as concerns man-assumes still 4tationary car or train-which isreally greater fascination. moving at approximately 1,000 m.p.h., the Is there a limit ? The speed of an aero- speed at which the Earth rotates or spins. plane, racing car or cycle, or anything else is necessarily relevant to some other body or Danger Aspect of Speed thing.The quickest speed of which we For practical purposes the speed of any have knowledge is that of light, which land vehicleis measured relative to the is 186,000 miles per second-one-seventh ground, a ship or boat relative to the water, of a second to encircle the Earth ; and that and an aeroplane relative to the air; when is identical with the speed of wireless waves we wish to refer to the speed of an aircraft and of radiant heat. Look up at the stars relative to the Earth's surface we speak of on a cloudless night (there are plenty of its" ground speed."Very high speeds, opportunities in the blackout !) and you short rapid turns, or rapid flattening -out will see approximately 3,000 of them out from a dive sometimes produces a " black- of a probable total of about thirty thousand out," or momentary failure of the pilot's million. Suddenly there may shoot across vision.At what speed the " black -out " your vision a meteor (misnamed " shooting would become fatal has yet to be demon- star ").Millions of these penetrate the strated.Intouchingon thedanger - Earth's atmosphere in the course of every aspect of speed it is as well to remember 24 hours, and mostly they are composed of that in the early days of railways, doctors iron -nickelalloy.But thepoint about positivelyandsolemnlydeclaredthat them hereistheir speed, whichisthe the human constitution could not with- 56 NEWNES PRACTICAL MECHANICS November, 1940

COMPARATIVE SPEEDS L /GH 77186,000. miles a second RADIO. 186,0oo. METEOR. so. It I( SOUND. 1,100. feet a second PROJECT/LE.3.000.- ft stand a speed in excess of about 20 m.p.h.water. Time taken for the sound of theregister themselves on ribbons of paper which The swiftest aeroplane's flightis buta. submerged bell to impinge on the metalare kept moving by clockwork motor. This crawl in comparison with the movements ofsheet and so travel to the recorder's eardevice gives the time taken to cover the mile the heavenly bodies, a challenge whichwas 91seconds.From which the twoto within one four -hundredth of a second. aircraftand a,ero-enginedesigners haveexperimenters deduced that sound travels always before them. They are working forthrough water at the rate of 4.706 feetTime-Space-Speed the day when the airman will not exactlyper second. The fascination which these hold over the meet himself coming back but will hear the Actually the stopwatch and eye methodimagination of mankind has given uh many approaching roar of his own aeroplaneis out of date now for timing where veryworks of imaginativefiction,the most some time after he has grounded ! high speeds have to be recorded, as whennotable of these being Jules Verne's "Round There is only one product of man's handscars are racing over a measured mile, anthe World in 80 Days," and H. G. Wells' which has greater speed than an aeroplane,error in timing amounting to only a fraction-Time Machine." We have still to catch up and that is a bullet from a rifle (or shellof a second, giving an exaggerated erroron Wells' experimenter who devised a means from a gun); its speed may be as great aswhen the speed comes to be worked out inof projecting himself into Time --travelling 3,000 feet per second.The firing of amiles per hour. The cine-camera is employedforward into history still to be made. But gun of any description demonstrates thenow in conjunction with the stop watch,Verne's imaginative race around the world slowness of sound in comparison with light.this method also being employed with racinghas been handsomely eclipsed in reality --by You see the flash an appreciable time beforeaeroplanes,'plane and stopwatch beingHoward Hughes and four companions who the sound reaches your ears-as also youphotographed simultaneously. The electricalin 1938 (July 10-14) flew the round trip in see a cricket ball in flight before you heartiming of a racing car is accomplished by3 days 19 hours and 8 minutes. Soon even the click of the impact between the ballmeans of a contact strip at each end of thethat will be bettered, when stratosphere and the bat. Sound is at a disadvantagecourse, the car as it passes over these stripsmachines cleave the thin air of the upper when travelling through air, as far as its(one at the start, the other at the end, of thelevelsatspeeds almostfrightening and rate of progress is concerned.Its speed ismeasured mile) causing electric currents toincredible. much greater through wood and through water,and14timesgreaterthrough steel.It is interesting to note how com- parative speeds of sound were first deter- mined. Two groups of scientists stationed themselves 61,047 feet apart, one group at First Use of Parachutes Montlhery, the other at Villejuif, France, each with two cannons and a chronometer. THERE are now so many remarkable The earliest British report in which the Each group fired its guns at ten-minute escapes by parachute that one some-enemy use of a parachute is mentioned intervalsandwiththechronometers times forgets that the last war wasappears to be one dated August 12, 1918. recorded the time which elapsed between theover before parachute jumping had passedA patrol of four British aircraft under sight of each flash opposite and arrival ofbeyond the experimental stage.For wellCaptain C. H. R. Lagesse saw four Fokker its sound. The light was registered withover a century previously inventors hadbiplanes east of Bailleul at 14,000 feet.All practically no time-lapse, whereas the soundbeen toying with the idea of leaping tofour enemy aircraft were destroyed. One took alittle over 54 seconds to arrivesafety from a great height.As far back asburst into flames at 1,500 feet.The pilot (1,100 feet travelled per second.) 1783 the Frenchman, Lenormand, jumpedpulled the aircraft up in a right-hand stall from the tower of Montpellier Observatoryand jumped out.After a drop of 200 feet Sound Through Water wearing an apparatus of his own invention.a parachute opened and the pilot landed. To determine the speed of sound throughThe aim in this case was to find a means ofAfter the war the "seat pack" type of water, two experimenters took up station,escape from burning buildings. parachute was developed in the United each in a boat, 44,237 feet apart, on Lake The idea of jumping from balloons wasStates Army Air Service, and has since Geneva. Their apparatus was cumbersome,developed about the same time by anotherbecome universal. but they got aresult.One boat wasFrenchman. Blanchard, who in 1785 suc- equipped with a bell and striker whichcessfully released a dog in a basket from was lowered into the water, and somea balloon.In 1793, he himself jumpee magnesium powder. The magnesium wassustaining some injury in landing.The Carving in Steel lighted with a match, -the same movementmodern use of parachutes was developed in AN engineer of Bognor Regis, Mr. H. Wiles. causing the striker to hit the submergedAmerica, the first jump from an aeroplaneAis, as far as is known, the first man bell.Thus light and sound originated atbeing made two years before the Great Warto Drove that it is possible to carve in steel. the same instant. The reception of theseat St. Louis, Missouri, by Captain Berry.That he has been successful is proved by the was recorded by the experimenter in theDuring the three years 1914-17 parachutesfact that he has already carved five busts, other boat, with the aid of a chronometer,were out of the picture.Then Germanand is now at work on a model three feet and a speaking -trumpetfittedwith apilots began to "bale out" with the attachedsquare. The only tools he uses are a small sheet of metal over thelarge openingtype of parachute which is stowed in thechisel and hammer and a burnisher for which was just below the surface of theaircraft. polishing the faces of his busts. November, 1940 NEWNES PRACTICAL MECHANICS 57 SCALE MODEL AIRCRAFT No. 7

Spitfire.It is fortunate that the elliptical wing has been discarded, as the similarity was then too striking for comfort !The main plane is notable for the fact that the main spar is placed nearly halfway aft from the leading edge in order to allow room for the undercarriage, otherwise it is of fairly normal stressed -skin construction. The ailerons are fitted with mass balances and large trimming tabs-probably with servo control. The flaps are unusual, because the inner sections are of the plain type (so popular with Axis designers), and the outer ones are of the more usual split variety. The pronounced inverted gull wing is a common Heinkel characteristic. A Powerful Engine The fuselage is of normal construction, with a sliding cover for the pilot's cockpit. The nose represents the neatest cowling yet made for any of the rather bulky Daimler Benz engines. That used on the He 113 is a development of the 1,150 h.p. DB-601 The Heinkel HE 113 By J. H. Stevens, A.R.Ae.S. The Latest and Fastest German Single -Seater Fighter

THE Heinkel He 113 is the productionfighters. In actual fact the original He 112liquid -cooled unit of 1,150 h.p., the modified version (embodyingallthelatesthad a maximum speed of 300 m.p.h., while1,500 h.p. DB-603. modifications) of the three -year -oldthe present He 113 is thought to do about These modern German inverted engines He 112 single -seater fighter.The He 112,400 m.p.h. are larger than the British Rolls Royce which was produced rather later than the Merlin and do not permit such a good nose original of the now well-known Messer-Simplicity of Production shape.Rearward -facing exhaust stubs are sehmitt Me 109, was a very typical Heinkel In ordertosimplify production, thefitted, but not the thrust -giving ejectors design with a graceful fuselage and ellipticalservice version of the He 112, the He 113,used on British machines. inverted gull wings.The original machineWas further modified and given a tapered The tail unit has been finished off in a was, even for1937,comparatively low -wing, which corresponds as nearly as possiblesomewhat " square -cut " style, also, appar- powered, with a Junkers Jumo 210 Eawith the original elliptical plan form. Theently, with a view to helping production. engine of only 650 h.p. ; yet it had a goodengine is understood now to be the newThe inset controls, servo tabs, and balance performanceandcarriedquiteheavy1,500 h.p. DB-603. hinges are worth noting. armament. The armament has had to be reduced The undercarriage legs hinge inwards and The alterations made in developing thebecause of the heavier engine and, insteadthe whole wheel aperture is closed by fair- He 112 to He 113 are of some technicalof two shell -guns in the wing, two synchro-ings on the struts and email plates hinged interest. A small batch on the lines of thenised machine-guns in the fuselage andbeneath the fuselage. prototype was built and tried out on therecessed racks for six 22 -lb. bombs under Luftwaffe',9testing ground-the Spanisheach plane, thereis only one shell -gun,Making the Model Civil War. The results there, by comparisonmounted on the engine and firing through The first question to be settled when with the Me 109, which had by then beenthe airscrew shaft, and two synchronisedmaking a model is the scale to be used and, fitted with a 1,000 h.p. engine, pointed toheavy -bore machine-guns accommodated inas this has already been dealt with at length the need for more power. The machinethe wing roots. in other articles of this series, little need be was taken in hand and the nose was enlarged As may be seen from the illustrations,said about it here.*One word to new to take either the Daimler Benz DB-600 orthe He 113 is a very clean machine, with See particularly" The Bonbon Paul Defiant," DB-601 engines of 1,000 and 1,150 h.p.fuselage lines not unlike those of our own " Practical Mechanics," August, 1940, pp. 481-2. respectively.The extra weight was com- Varnished pensated by moving the retractable radiator wooden back almost under the pilot's seat. The die cut Spinner without from a lathe undercarriage legs were arranged to fold fuselage inwards instead of outwards. The protrud- Typical cockpit ing streamlined cockpit cover was faired Trim pressing U/C leg and back to the fin with built -on light -alloy surplus with hinge recess panelling. The fin and rudder were enlarged razor blade to compensate for the extra torque of the more powerful engine and the resulting Rolled paper aeroplane was very like the present type. to represent 'Silk thread This machine was stripped, fitted with a shock absorber Fig. 3. specially " hotted -up " engine (which, inci- cylinder forming dentally, was thrown on the scrap heap after dummy Pin retracting the one flight), and used to set up a world's Plaster of main speed record of 464 m.p.h. in April, 1939- strut oar's female )144E''' this record being raised 5 m.p.h by the die Messerschmitt Me 113 R three weeks later. Fig. 2. S .C4 Forpropagandapurposesbothrecord Matchbox mould case breakerswerepublicisedasstandard Figs.Ito 3. Constructional details for making the model 58 NEWNES PRACTICAL MECHANICS November, 1940 modellers, which might not be out of place.delicate to model.For the small fairingitself gripped in a vice (it must be very close is, take care in the choice of a scale and,plates, and those of the main wheels, tinyup and firm or the pin will bend and all the once it has been decided upon, stick to it.cloth (silk or. fine cotton ribbon) hinges willcareful work go for naught), and finish off as the chance of being able to make directbe found quite satisfactory. by rounding with a file and then fine glass- comparisons, 'model to model, adds greatly paper.This improvised lathe works quite to their interest. Making the Airscrew well for light finishing work, but is not up If a collectionisintended, thesolid Quite good cast model airscrews can beto rough shaping. The blade root positions model, i.e. carved from blocks and planks ofbought at model dealers, many of them forshouldbelocated and carefullydrilled wood, as opposed to being built up with1/72nd scale, but it is qiiite a simple matterwhile still held in the drill chuck. framework and covering, is by far the best.to make one for this model.If a lathe is The airscrew blades are simply filed from For this type of model the best material isavailable, the spinner should be turned upfibre and glued into the holes in the spinner. fairly soft and,ifpossible, close -grainedfrom wood or metal, according to choice. wood. In these days it may be necessary toHowever goodone'seye, it is impossible toColour Scheme make do with deal or pine, but in these themake an absolutely symmetrical spinner by The He 113 is simple enough to paint- grain is fairly open, and the tendency whenhand, and the following method is recom-at leastas long as the present colour scheme glasspapering is for it to become slightlymended for those not fortunate enough tois retained.The main colouring is a very furrowed. The bestmaterialsincludepossess a lathe-or a friend with one dark shade of green (darker than olive American whitewood (or bass), beech, birch. Obtain a piece of close -grained hardwoodgreen and bluer in tone) with very pale satin walnut (in fretwood form for the mainand square it up to the outside dimensionsblue orlight stone -colour undersurfaces. planes), plane, boxwood, or holly-the twoof the spinner, draw diagonals on the end,The German black cross. heavily outlined latter being rather more rare,but verymark a circle from the centre so found, andin white, and the outline itself edged with good.The tail surfaces on a small-scaledrill a hole carefully down the centre of theblack, is carried on the sides of the fuselage model are very conveniently made from theblock. (At this stage the radial positioningand on both surfaces of the wing. A small red fibre which is used for making washers.of the three blades should be clearly markedblack, white -outlined swastika is painted As it has no grain and is very tough, thison the rear end of the spinner block.) Nexton the rudder. The airscrew blades and the material is easy to shape and there is nodrill a hole the size of the shell -gun bore inexhaust pipe are black. The interior of the risk of splitting. one end to a depth of about one -quartercockpit is light grey. The first squadron of the length of the spinner, and glue a pinwhich illustrations have appeared has as a The Transparent Cockpit Cover firmly inthe main hole(Fig. 3). Nowdistinguishing marking. a conventionalised When the fuselageis carved from thecarve the block down to an octagon andlightning streakon the engine cowling. chosen block of wood, the cockpit sectionfinally a 16 -sided figure, then carve it to itsIndividual machine numbers (it is believed, should be shaped with therest.. Oncecorrect pointed shape, always continuingfrom 1 to 12) are painted in white on the shaped, it should be carefully cut off intactthe 16 facets.Finally, mount the spinnersides of the fuselage. The illustrations show with a fretsaw.It is then mounted on aby its pin in the chuck of a hand brace the exact location of all these details. stick, varnished, and used for the male die for producing the transparent cover.The material for this cover is thin cellophane orSIDE, PLAN AND FRONT VIEW OF THE eellidoid-the stoutest available commercial wrapping would be best.A female die is produced by making a plaster-of-paris east HEINKEL HE 113 of the male tool. The tools and material are prepared fiti A B action by being heated: the former in an oven, or by gently heating it by a fire, and the latter by " cooking " in very hot water. 'C'"n17 Gloves are advisable in doing this work, as every part is hot.When ready, the tools are put in a convenient working position. the cellophane removed from the water (in which it should have been suspended by a piece of string), dried on a cloth, laid across the mould and the die pressed quickly and 4ABAB c_e_c firmly in place. The first attempt may not be a success:the most likely cause of failurebeingtoorapidcooling of the material.Though an excessive surplus of cellophane, with consequent wrinkling may also be a contributory cause. The Retractable Undercarriage The undercarriage of the He 113 is very simple and can be made from brass wire of a gauge appropriate to the scale being used (large pins will be found very useful, as the heads serve toretainthewheels more neatly than can be done with wire). A cross shaft of wire is soldered to the top of each leg in order to act as a hinge (see Fig. 2), which is let into a slot in the undersurface of the wing and packed with plastic wood Care should be taken that the leg rises cor- rectly into its slot before final fitting. The shrinkage of the plastic wood when it dries ( should give ample clearance on the hinge: if it does not it can soon be worked free. For a small-scale model, i.e. 1/72 or less, the little retracting strut presents a tricky problem, and it is suggested that the sim- plest way is to glue a silk thread that will he taut when the leg is down.The small 0 3 fairing plates under the fuselage can be SCALE OF FEET used as catches to hold the legs up.The main fairing plates are perfectly satisfac- tory if made of stiff paper which, once it is painted, is amply strong. Y The retractable tail wheel is made in a similar way. but is, of course, even more November, 1940 NEWNES PRACTICAL MECHANICS 59 A Magnetic Tape Recorder -Producer Auditory Perspective and Magnetic Tune Recording

several respects as a pure public address system in addition to its reproduction of speech. Making a Recording Each performance began with the selec- tion of a group of five people who were ushered into an anteroom where, with an interlocutor, they decided on the subject of conversation. As soon as the platform was vacated, it was moved into the wings, and the group took their places on the chairs. When the previous demonstration had been completed, the platform was rolled back into view of the audience, and the interview began.Visible to the interlocutor but to no one else was a large voltmeter connected to a potentiometer driven by the recorder; Fig. I.-Showing an audition demonstration in progress. thus the pointer indicated elapsed time. When about two minutes had passed, the IN the fundamental plan for the Bellium, both as to shape and to the acousticinterview was concluded, and the party System Exhibitatthe New Yorktreatment, some small part of the soundwalked down a path to take seats ona World'sFair,participationby theprojected by the loudspeakers found its waybench. Meanwhile attendants (Fig. 3) had audience wasconsideredessential.Tothrough the opening of the proscenium archset up lay figures on a second platform apply this to a demonstration of auditoryinto the platform space.This space alsowhich came into view as the first one was perspective and magnetic tape recording- withdrawn. The interview was then played two important contributions of the Bell back to the audience and to the particular Laboratories-itwasdecidedtohold group which had made the recording. successive interviews with members of the Two identical recording -producing chan- audience and reproduce them from tape nels were used to give auditory perspective; recordings. That the platform might one of these is shown in Fig. 5. From the be empty during the reproductions, the microphone the sound signals were trans- interlocutor and his group were replaced by mitted through amplifiers to a" baffle layfigures. Electricaland mechanical equaliser," which corrected the response arrangements for this involved considerable characteristicsofthemicrophone -and - ingenuity, both in the planning stage and baffle combination. Next to that was the as construction proceeded. dialogue equaliser, used because the speech level projected to the audience was con- Design Problems siderably higher than that produced on the Technical requirements for the audition platform by the talkers.Its higher toss at exhibit were dictated by considerations of the low end overcame the guttural sound of good showmanship and presented a number Fig. 2.-One of the magnetic tape recorders. speech at high level. of design problems. For example, no micro- phones,loudspeakers,controlorotherrequiredcarefuldesign to prevent theThe Horn System equipment shouldbevisiblefromthereflection of stray sound toward the sensitive During the recording cyclethe horn audience area ; no screen or glass shouldregion of the microphones while presentingsystem was used to reinforce the speech so separate the talkers on the platform fromthe maximum direct sound from the talkers.that after passing through the limiting the audience ;the conversation, normallyIt is readily seen that this system is novel inamplifier the circuit divided two ways, one carried on at rather small volume, must be projected with sufficient level to be easily understood at any point in the audience area in spite of normal audience noise. A two -channel stereophonic system was se- lectedwitha view toward maximum naturalness rather than emphasising local- isation of the sound source. A standard theatre system of two -element loudspeakers was installed above the upper corners of the proscenium opening on each side, and hidden by motion -picture screening. The tiny openings in the screen were invisible from a distance but presented little obstruc- tion to the sound from the loudspeakers. The microphones were located just back of the loudspeakers near the ceiling of the platform area, out of sight of the audience. Each microphone was placed in a large box -like baffle made of layers of muslin stretched on a frame -work.The baffles were highly directional, which serves two purposes, first, to provide satisfactory sound pick-up at a distance of twelve to eighteen feet, and, second, to make them relatively insensitive to sounds entering the platform space from the audience area. In spite of the excellent acoustic design of the auditor - Fig. 3.-Lay figures being placed in position on the platform. 60 NEWNES PRACTICAL MECHANICS November. 1940 normal frequency characteristicof tapeThe control relays ensured that the tape recording.Signals were then transmittedcould then be driven only in the forward to another amplifier, volume control, thedirection, and that the circuit of Fig. 5 was limitingamplifier(whichinthiscaseswitched for reproducing. A contact, closed operates like an ordinary amplifier), and towhen the section of the platform carrying the loudspeaking system on the stage. the mannequins was in position in full view of the audience, started the reproducing cycle. Maintaining Synchronism The reproduction continued until its elapsed In the magnetic -tape recorder -reproducertime had been equal to the recording time. shown with cover open in Fig.2, aseparateThe tape then rewound automatically as tape was associated with each channel.before. Itwasnecessarytointerlock Synchronism between the channels wasmechanically andelectricallyallthese maintained by winding the two separateoperations to take place in a definite order tapes simultaneously from the left-hand reeltorelievetheinterlocutorsofcontrol to the right-hand reel,one tape goingsequence and to protect the equipment through the near recording units and thefrom control errors. other tape passing through the far recording unit.This method is simple and no diffi-Three Machines Installed cultywasexperiencedinmaintaining Since this equipment was in operation for synchronism of a higher order thanis thirteen hours a day and seven days a week, necessary for stereophonic reproduction. three of the machines were installed, the Whentheinterlocutorstoppedthenominal arrangement being that one was in recording of the conversation on the plat-use, one stand-by and the third available form by pushing a button, the tape drivefor maintenance and test.The amplifying was stopped by the release of a forwardequipment associated with these machines driving clutch. The tape was then rewoundwas mounted on the three relay racks shown at high speed by the operation of the leftin Fig. 4. Fig. 4.-The first two panels (from the left) mountclutch which connected the nearly empty During the twenty-nine weeks of the left-hand reel to the rewind motor. ThisNew York World's Fair, about 110,000 amplifiers,channels 1 and 2respectively; on the right-hand panel are monitory loudspeakers and the clutch was finallyreleased by a cam -persons took part in the auditions, while announcer's emergency amplifier. operated contact before the tape was com-many times that number enjoyedthe pletely unwound from the right-hand reel.demonstrations. to the public address system and one to the recording machine. The limiting feature MICROPHONE LOW- in the amplifier prevented overload of the IN BAFFLE FREOuliNC tape under unusual circumstances, such as loud laughter, and was not called into play luring theusualrecording.The horn 3qualiser, the characteristicof which is DIVIDING LOUD shown, was adjusted so that the combination NETWORK SPEAKER'S 50 BAFFLE DIALOGUE HORN loudspeakersprojected aflatfrequency tt* EQUALIZER EQUALIZER EQUALIZER characteristic to 7,000 cycles. The amplifier, dividing network and loudspeakers were ici2 1o0 104 ::haracteristic of a good theatre installation. DB10 HIGH"' At any time that recording or reproducing 20 FREOUENCY was not actually taking place, the horns were FREQ. DU mm r disconnected from the circuit and a dummy LOAD load placed on the output of the amplifier. ttp During reproduction of the conversation LIMITING the relays in the centre of Fig. 5, made contact downward with the result that the signals from the tape went through an Fig. 5.-A diagram REPRODUCER amplifier to a reproducer equaliser, the 30 EQUALIZER of one audition function of which was to compensate for the 44 TAPE MACHINE channel.

instrument board. Cars thus equipped and operating over a test section of New Radio Traffic Control York City highways, were described over America Solves the Traffic Problem the N.B.C. Blue network recently. Recorded Messages

NOVEL plan to bring traffic signalsr The small highway transmitting unit, into cars in the form of distinctive LATE DELIVERY OF 1which may be mounted on a telephone pole tones corresponding to thestop or a traffic light stanchion, makes use of a and " go " lights, may in time make a car - "PRACTICAL MECHANICS" magnetic tape sound recording device by radio a legal requirement on every one of I AMessage from the Editor which continuous repetition of a traffic the nation's 30,000,000 ears, according to I e are doing all we possibly can to bulletin or a safety message may be broad- the men behind the plan in America. ensurethat"PracticalMechanics" cast. A distinctive sign placed on the street In its present form, this traffic -control reaches you regularly every month, but or highway in advance of a given radio zone system uses the existing car radio tuned to occasionally there may be a delay owing calls attention of motorists to the radio 550 ke., thus making the system immediately to the dislocation of transport caused by system which they are approaching and tells availableforthe6,000,000carsnow air raids. them the frequency to which to tune their equipped with auto -radios, though even- If, therefore, " Practical Mechanic -9" set. tually a special small set would-be employed should arrive after the normal day of Preventing Traffic Jams with fixed tuning to the highway safety - sale,please help your newsagent by signal frequency. accepting your copy as usual. Under By means of this device, traffic can be By the use of this system. the driver. the Government's Paper Control Order re-routedtoasecondarythoroughfare instead of letting his attention wander from I he -is unable to return unsold copies, and from crowded highways, preventing jams the roadway in his search for traffic signals if you refuse to accept he will have to before cars have a chance to pile up : inunfamiliarterritory,wouldheara pay forit himself. drivers can be warned of speed limits or of pleasant low tone as long as the lights ahead Your newsagentisworking under emergency in case of fire or accident ; doc- were green. When " red " collies on, in all difficult conditions these days, and your tors can he paged on the road or pedestrians ears on that section of the roadway an kind co-operation in this matter will be can be warned of an impending change in interrupted high note would be heard, like greatlyappreciatedby him-and by trafficlights. The robot can give oral crossing signal.If desired, relays could be ourselves warning of such impending changes to installed which would switch on the ear 1 drivers and pedestrians also. November, 1940 NEWNES PRACTICAL MECHANICS 61 A NEW SERIES The Story of Chemical Discovery No. 4-Scientific Chemistry Begins

ALCHEMY, toallpracticalintents disposition, strictly interpreted the injunc- and purposes, closed its long and tion of the New Testament not to swear tortuous career with the passing of " neither by heaven, nor by earth, nor by John Baptist van Helmont, the Brussels any other oath." physician, in 1644. Van Helmont, " the last Such was the Honourable Robert Boyle, of the alchemists," had played a certain the individual who has ever been said to part in preparing the way for the coming of have " worn the white flower of a blameless scientific chemistry. Nevertheless, at heart, life." Such was the man who gave scientific van Helmont remained to the end an chemistry its first impetus, who disentangled alchemist and a follower of fanciful theories, scientific thought from the wrappings and an individual who preferred to speculate trappings of alchemy and who, in every upon supposedly mystical matters con- possible way, proved himself to be one of nected with the chemical arts rather than to the earliest pioneers of scientific research, search actively for strictly logical explana- not only in England, but in the entire world. tionsof thechemicalfactswhichhe Boyle has been called" the " Father of undoubtedly brought to light. Chemistry."It is a true title, for although Boyle's actual chemical discoveries were Honourable Robert Boyle not in any way striking, it was he who first When van Helmont died, there had just insisted on that which we may call the returned to England after a protracted tour chemical method of scientific investigation on the Continent, a youth of noble family, which was to become so enormously fruitful one Robert Boyle, born in 1627, the 14th in after years. child of a certain Baron Youghall, Viscount of Dungarvan and Earl of Cork.Robert " Boyle's Law " had received his education partly at Eton, Boyle is known to every schoolboy as the but for several years he had, in the com- discoverer of that famous law connecting pany of a brother and a French tutor, the relations between the pressure of gases wandered up and down Europe in a some- and the volumes which they occupy.This what desultory fashion and with apparently law, known afterwards asBoyle's Law," no particular object. The Honourable Robert Boyle, founder ofEnglish was first published in 1660, after Boyle On his return to London, Boyle found Chemistry. had invented and perfected a new form of that his father had died and that he had air pump. Boyle did a good deal of experi- inheritedcertainestates,bothinthisbecause it met secretly. During his later lifement on the subject of atmospheric pres- country and in Ireland. He was, however,Boyle had much to do with the running ofsure, and itis to him that we owe the not of the temperament to settle down con-the Royal Society.Yet he would neverintroduction of the term " barometer." tentedly to an aimless country life. For oneconsent to become its president, for the It was Boyle who first drew attention to thing, his thedarken - Principle of Fireing of silver healthbad and, was The Strange Theory of " Phlogiston, or the salts by light, furthermore, he was possessed of studiouscharter of the Society prescribed the takingupon which fact the whole edifice of photo- habits, which made the idea of completeof an oath upon accession to that office, andgraphy has been reared. He, too, it was who inactivity particularly distasteful to him. Boyle. being of a very devout and religiousdiscovered phosphoric acid, wood alcohol, Thus it was in the end that the Honour- several luminescent substances, and various able Robert Boyle settled down at Oxford chemical salts. He was the first maker of - in 1654-10 years after van Belmont had phosphorus in England, and he seems to died-and in that famous city of learning havedistinguishedbetweenacidsand devoted himself entirely to scientific research. alkaline substances by means of vegetable Boyle spent 14 years in Oxford. Then he colour tests. went to London -and remained there for the Boyle's great service to chemistry, how- rest of his life. ever,liesinhis sweeping away of the A curious fellow was Boyle. He was pale fantasticalelements " of the ancients and and emaciated and very delicate constitu- of the alchemists. Although he did not dis- tionally. Mentally, he was at times subject tinguish the chemical elements as we know to fits of something akin to melancholia. As them, he introduced the first clear concep- one contemporary puts it: He had divers tion of what an element really is.Such a sorts of cloaks to put on when he went notion he set forth for the first time in a abroad, according to the temperature of the rather remarkable book which he entitled, air, and in this he governed himself by his The Sceptical Chymist and which was pub- thermometer." For nearly forty years it is lished in 1661.In The Sceptical Chymist said that he laboured under such a feeble- Boyle demolishes the old Aristotelian and ness of body and depression of spirits that alchemical theory of elements, producing itwas astonishing how he could read, clear and convincing reasons for so doing. meditate, perform experiments, and write as he did.Yet, somehow or other, Boyle Elements provedhimself tobe an indefatigable " I mean by ' Elements,' " says Boyle in worker. He left six folio volumes of scien- his book, " certain Primitive and Simple or tific works, many of them connected with perfectly unmingled bodies which not being chemistry, and all of which constitute a made of any other bodies or of one another mine of information concerning the begin- are the ingredients of which all those called nings of scientific research in England. perfectly mixed bodies are immediately compounded, and into which theyare The " Invisible Society " ultimately resolved." Boyle was one of the founders of the In other words, elements are bodies or Royal Society, which began as the " Philo- A primitive microscope of Robert Hooke'., day.It issubstances which cannot be resolved into sophical Society,"or,as Boyle himselfmade of wood and cardboard and is equipped withother substances. They have a fundamental preferred to call it, the " Invisible Society," only a single lens. " one-ness " throughout, but by combining 62 NEWNES PRACTICAL MECHANICS November, 1940

together in various proportions they are ableconcerning flame and combustion sank intoweight.For example, if a piece of lead be to give rise to numerous other compounds.obscurity after the deaths of their authors.calcinedinair,the" lead calx "(lead Boyle had an assistant at the RoyalIn place of them came the German theory ofoxide) which isleftis heavier than the Society,aclever experimenter and an" Phlogiston," which saddled the scientificoriginal mass of lead.And, in a like man- originalthinker,albeitacrabbed,ill- world for a century before it was finally dis-ner, if a piece of coal be combusted, the temperedmorose sort of a fellow who,pelled and a return was made to the correctweight of the ash plus the weight of the during his last two or three years of life,theory of the two former English experi-gaseous products of combustion exceeds the sat night and day at a table and never wentmenters. original weight of the coal. to bed or undressed himself, so engrossed ThePhlogiston " theory of combustion was he in his scientific studies. Robertbegan with one John Joachim Becher, ofUniversal Law Hooke was this man's name. He was bornSpeyer, in Germany, who was born in 1635, Such a law is a universal one, and it in the Isle of Wight, in1635, and wasand who died in 1682. Becher retained theadmits of no exception. Since, however, the originally intended for the Church.Butalchemical notion of the metals containingphlogiston theorylaidit down that a Hooke, like Boyle, was delicate, and after a" three principles," the nitrifiable, the mer-mysterious something (called phlogiston) somewhat erraticcareer,heultimatelycurial, and the combustible, and he reasonedactually escaped from a burning substance, became, in 1662, " Curator of Experiments that during the burning of a substance itsit ought naturally to have followed that the to the Royal Society combustible principle was expelled, beingash or calx, or whatever the product(s) of wafted away into the air via the flame ofcombustion may have been should have Robert Hooke the burning material. weighed less than the original weight of the Hooke's work was many-sided, and for AfterBechercameanotherGermancombustible material.Instead, however, a that reason we cannot pretend to deal withchemist, one George Ernest Stahl, who was fewinvestigators - daringspiritswho it in detail here.There is one aspect of it,horn at Anspach in 1660, and died in Berlinrebelledagainsttheimpositionof the however, which we must stress. Hooke wasin 1734.It was Stahl who put on its feetfradulent phlogiston theory-showed con- probably thefirstchemicalscientisttothe now famous but long discredited theoryclusively that the combustion products of formulate any reasoned explanation of theof " Phlogiston."Stahl. who was Becher'scombustiblesubstanceactually weighed phenomenon of combustion. pupil, took the germ of his " Phlogiston "more than the original material. Hence, as Hooke's work on combustion is a veryidea from his master and merely elaboratedthey said, the phlogiston theory could not important landmark in chemical history. be correct. Fromtimeimmemorial,mankindhas To all of which statements, George Ernest naturally been interested in combustion. Stahl,thecomfortable and self-satisfied with its accompaniment of flame and fire. German, replied that " phlogistonis,in Exactly what flame and fire are, no philoso- addition to being a principle of fire, also a pher before the time of Hooke had ever been principle of levity." able to explain.Itis,however, to the In other words, phlogiston is a sort of credit of Robert Hooke that he arrived at essence of lightness.It weighs almost less the opinion that the burning of a com- than nothing. Or, at any rate, its presence bustible (or, as he termed it, a " sulphure- in a substance cause's that substance to ous ") material, as, for example, charcoal, Boyle's own repre- weight actually less than it would do were is due to the combination of it with a sentation of his air the phlogiston to be absent from it.Hence substance existing intheair. Such a pump.With the aid by adding phlogiston to a material you gave substance, also, said Hooke, exists in salt- ofthisinstrument additional lightness to that material.The petre (potassium nitrate), because charcoal heformulated Usingcalled phlogiston was very different and saltpetre can be made to burn in a from anything else known. Not only was it vacuum when heated by means of the sun's " Boyle..s Law" the principle of lightness, but it was also rays focused by a burning glass. all-pervading. Hooke published his ideas of combustion When air was saturated with phlogiston, in a curious work entitled,Micrographia, combustible materials would not bum in it. whichdealtmainly withmicroscopical 'I'his supposition explained the fact that observations which he had made.Itis combustible materials would not burn in an probably for this reason that they were atmosphere of nitrogen or carbon dioxide. overlooked, for Hooke's guess at the real Ordinary air (containing oxygen) was said nature of combustion was so astonishingly to contain little phlogiston.Hence when. accurate that it is hardly credible that his combustible materials burned init,their views should have been for more than a constituentphlogiston readilyescaped (enturysubsqeuentlysupplantedbyathe theme, making itplausible and pre-into it. totally erroneous theory which held thesentableinthecharacteristicGerman scientific world in its grip until repeatedfashion. Strange Theory experiment eventually elucidated the real Combustion And so the strange and ludicrous theory nature of fire and flame and so confirmed ofphlogistonwent on and had its way. So theremarkableexactitudeofHooke's According to Stahl. when a substancewidespread did it become that nearly all original supposition. burns it emits a mysterious entity whichthe famous chemical investigators of the was to be known asphlogiston,a word which18th century became adherents of it.The John Mayow be derived from the Greekphlogisteo, I setrenownedJosephPriestley,apioneer John Mayow, a contemporary of Hooke'son fire." Phlogiston, therefore, according tochemical discoverer, lived and died a. con- and a Cornishman by birth, also arrived atStahl's theory, was a principle which wasfirmed " phlogistonist." When he discovered similar conclusions independently of thecontained by all combustible bodies. Whenoxygen, he calleditdephlogisticated air, former experimenter.Mayow for a timesuch substances burned, their phlogistonbecause, as he imagined, the oxygen sup- followed the profession of law, " especiallyexcaped. Materials which burn readilyported combustion so vigormisly that it in the summer at Bath," but he was scien-contain a good deal of phlogiston.Sub-must be almost entirely devoid of phlogis- tifically inclined and he devoted much timestances which do not contain much phlogis-ton.Combustible material burning in this to the study of the human body. Mayowton do not burn easily. gas emits a copious flow of phlogiston into showed that the dark venous bloodis Thus carbon (charcoal) was supposed tothe gas, which latter absorbs the phlogiston changed to bright red blood in the lungs bybe nearly pure phlogiston, whilst metaleagerly and readily. taking up an unknown substance from the(such aslead)which, when they were Such, in brief, was the now often -referred - inhaled air, which unknown substance heburned (or oxidised) became converted intoto theory of phlogiston.Phlogiston, how- called the " nitro aero " constituent of air." calces " (or oxides), were supposed toever, constituted a scientific deception of He seems to have realised, like Hooke, thatconsist of a mixture of phlogiston and suchthe 18th century and of most of the chemists flame and fire result from the combinationcalces. of that age.It was a German -imposed of the burning substance with some ingredi- Thus : theory based upon unwarranted assump- mit of the air. Had he lived, John Mayow Metal phlogiston -I- metal calx (oxide). tions and with little regard for actual facts. would undoubtedly have made Ms name as Had those early chemists made greaterNevertheless, it had its usefulness in stimu- e pioneer chemist, but he died in 1679 atuse of the chemical balance the tremendouslating chemical research and discovery, for, the early age of 35, having been married aand century's -duration error of phlogistonafter all, it did at least make some attempt short time previously, and " not altogethermight probably never have arisen.Stahl,to explain the age -long phenomena of flame to his content," as a contemporary some-the originator of the phlogiston theory, andand combustion without having recourse to what bluntly puts it. his followers, entirely overlooked the factthe many ridiculous speculations of the The early theories of Hooke and Mayowthat when a substance burns it increases inancients upon such matters. November, 1940 NEWNES PRACTICAL MECHANICS 63 you find convenient, with the object of establishing a simple routine. After each of the cards has been indivi- dually studied, shuffle them together and test your recollection of the points observed by correctly naming each card. You may fail at the first attempt, but reshuffle and try them again until you recognise each one instantly. Do not fall into the easy trap of remem- bering the landscape or recognising the y R. A. Saville-$neath

pilot's face.Short cuts of this kind tc ill not help you to recognise machines in the air. When your card test shows you to be name -perfect on your first selected objec- tive, which may, for example, include an Avro Anson, you will on next noticing this machine in the air be surprised to find that you are really seeing it for the first time. You will take note of the low wing position ; two engines of radial type, with fluted cowling ;the large glazed cabin or " con- servatory " ; the domed gun turret aft, and the unusual shape of the tail plane.As A flight formation of Handley Page "Hampden each of these points, noted, in turn, now Aircraftecognition Suggestions for Home Study THE general interest in aircraft recog-2. The number of ENGINES. confirms your own mental picture, your nition needs little explanation. 3. TAIL UNIT, whether simple or com-previous vague uncertainty of recognition Whether we play an active part in pound, i.e. single fin and rudder or twodisappears.As the plane recedes in the any of the defence services or pursue our or more. distance, you no longer regarditasa normal civilian occupation, in totalitarian4. Special features and general shape ofmeaningless silhouette, but as a friendly warfare all are targets and few escape some FUSELAGE. shape, which you will have no difficulty in concern with the subject. 5. Type of Engine (Radial or In -line) andrecognising again. Wintry conditions may be less favourable position of engine nacelle. In some eases a slighteffort may be to mass attacks, but they provide better5. Type of UNDERCARRIAGE, whetherrequired before facility is acquired in recog- cover for lone raiders and for hedge -hopping tactics. Prompt spotting of a hostile plane may enable one to get family or neighbours under cover before the deadly business begins. Lockheed Apart fromthespeciallyair -minded HUDSON student, the usual reaction to an array of aircraft silhouettes is one of bewilderment, which increases as many new types are added. The man in the street; no less than his service colleagues, may, with very little Handley Page effort, acquire a useful knowledge of the HAMPDEN subject. A photographic mind or an abnormallyretentive memoryisquite unnecessary so long as a few simple rules are observed and adefinitemethod is followed. Fix a Limited Objective Avoid the attack of mental indigestion which may followa hasty attempt to memorise many types, by firmly fixing a modest objective.If you are already able to recognise six different British aircraft, make your immediate objective twelve.If, however, you are not completely certain of six, take that modest figure as your goal. In selecting the first objective, choose those friendly machines which are most Armstrong Whit worth WHITLEK IV & frequently seen in your neighbourhood. Cut out illustrations of them whenever you get the chance and paste these on to cards, firstof all removing the name of the fixed or retractable, etc. machine.Whilst doing so, note carefully Itis an excellent thing to Three types of English bombing the principal structural differences, such'as :follow a definite sequence as here planes showing thedistinctive 1. Whether high, mid, or low WING. suggested, or any other which wing formation 64 NFWNES PRACTICAL MECHANICS November, 1940 November, 1940 NEWNES PRACTICAL MECHANICS 65 SOME OF THE "ANY INTERESTING TYPES OF AIRCRAFTIN SERVICE WITH THE HOW TO RECOGNISE THESE MACHINES BY THEIR DISTINCTIVE FEATURES

Hawkey 'Hurricane' single - seaterfighter. 1,030h.p. knits Royce -Merlin" engine BouIton-PaulDefiant" two-seater fighter. 1,030 h.p.Rolls Royce "Merlin" engine

Bristol "Blenheim" Mark 1 medium bomber Two 840h.p. Bristol ------31111111111164e24:-.;J"" -Mercury" engines Vickers Supermartm 'Spitfire' ingle-seaterlighter 1,030h.p. Rolls Royce "Merlin" engine

Fairey"Battle" high-speed medium, bomber 1,030 h.p.Rolls Royce" Merlin' engine

Gloster "Gladiator' single -seater 'ighter830 h.p. Bristo' "Mercury engine Bristol "Blenheim" Mark IV long- range -fighter bomber. Two 900 h.p. Bristol "Mercury" engines

Handley-Pags. 'Hampden" medium bomber Two 980 h.p. Pegasus " engines Bristol Bombay" homber-troop carries Two 1,000h.p. Bristol 'Pegasus" engines

Vickers'`Wellington'.medium bomber. Two 980 h.p. Bristol 'Pegasus'. engines ri

Blackburn"Skua" dive - Handley -Page "Harrow" heavy bomberfighter. 830h.p. bomber. Two 925 h.p. Bristol"Pegasus" engine "Pegasus" engines Armstrong -Whitworth "Whitley 1 Vickers "Wellesley" long -rang< heavy bomber. Two 1,030h.p medium bomber. 900 h.p. Bristo Rolls Royce "Merlin' engines "Pegasus" engine 64 NFWNES PRACTICAL MECHANICS November, 1940 November, 1940 NEWNES PRACTICAL MECHANICS 65 SOME OF THE "ANY INTERESTING TYPES OF AIRCRAFTIN SERVICE WITH THE HOW TO RECOGNISE THESE MACHINES BY THEIR DISTINCTIVE FEATURES

Hawkey 'Hurricane' single - seaterfighter. 1,030h.p. knits Royce -Merlin" engine BouIton-PaulDefiant" two-seater fighter. 1,030 h.p.Rolls Royce "Merlin" engine

Bristol "Blenheim" Mark 1 medium bomber Two 840h.p. Bristol ------31111111111164e24:-.;J"" -Mercury" engines Vickers Supermartm 'Spitfire' ingle-seaterlighter 1,030h.p. Rolls Royce "Merlin" engine

Fairey"Battle" high-speed medium, bomber 1,030 h.p.Rolls Royce" Merlin' engine

Gloster "Gladiator' single -seater 'ighter830 h.p. Bristo' "Mercury engine Bristol "Blenheim" Mark IV long- range -fighter bomber. Two 900 h.p. Bristol "Mercury" engines

Handley-Pags. 'Hampden" medium bomber Two 980 h.p. Pegasus " engines Bristol Bombay" homber-troop carries Two 1,000h.p. Bristol 'Pegasus" engines

Vickers'`Wellington'.medium bomber. Two 980 h.p. Bristol 'Pegasus'. engines ri

Blackburn"Skua" dive - Handley -Page "Harrow" heavy bomberfighter. 830h.p. bomber. Two 925 h.p. Bristol"Pegasus" engine "Pegasus" engines Armstrong -Whitworth "Whitley 1 Vickers "Wellesley" long -rang< heavy bomber. Two 1,030h.p medium bomber. 900 h.p. Bristo Rolls Royce "Merlin' engines "Pegasus" engine 66 NEWNES PRACTICAL MECHANICS November, 1940

Low wing monoplanes is suggested as aHampden, Lockheed -Hudson, Whitley. position useful basis for preliminary Obviously itis an easy matter to dis- study tinguish aircraft in sub -division (a) from Albatross Hurricane those in sub -division (6), but each of the Anson Lerwick three machines in the respective groups is of Battle Lockheed -Hudsonsimilar general structure.Following the Blenheim Lysander suggested routine procedure, we must now BeaufortMagister compare details of the fuselage. Fluted BombayMaster The BEAUFORT has a strong family cowling Defiant Roc likeness to the BLENHEIM, from which it Ensign Skua was developed. Of the two Blenheim types, Flamingo Spitfire the later Mk. IV, or long -nosed version,can Hampden Sunderland be readily distinguished from Mk. I, the Harrow Wellington short -nosed version, or Blenheimfighter. HarvardWhitley The Beaufort most closely resembles the Choose from these yourMk. IV, having a similar long nose.The first 6 or 12 of the types whichfuselage is much deeper forward and has a you most frequently see indefinite step-down orshoulder " aft The AVRO ANSON the air. Beaufort turret mounted at this shoulder, facing aft, is quite different from the gun Selection by Structural turret of both Blenheim models. The Avro An-Features sonwhich isa Within the same group the chief dis- low -wing mono- In some cases it is helpfultinguishing points of the WELLINGTON plane tochooseforpreliminaryare : unusuallyhighfinandrudder ; study a group of machinesstraight -tapered wings of high aspect ratio ; designed to the same general Large glazed cabin formula.. Atten- tion isthen more clearly focusedupon their individual characteristics. nising the first dozen types. As soon as this The 24 named monoplanes stage is reached, further progress is easy, asproviderepresentativesof Lodi -treed HUDSON long as the principle of limited objective isfour principal structural followed. One, two, or three new types maygroups, e.g.: be added weekly according to individual1. High Wing. - Bombay, aptitude and opportunity. Ensign, Flamingo, Lysander Know Your Friends First 2. Mid Wing (including low mid wing). - Blenheim, Just as in daily lifeu e recognise our Beaufort, Hampden, Lock- friends without conscious analysis of their heed -Hudson, Wellington, features; so eventually with aircraft fea- Whitley. tures, the final stageis familiarity and3. LowWing. - Albatross, Handley Page HAMPDE/V effortless recognition.Although you may Anson,Battle,Defiant, have made no serious effort to memorise the Harvard, Hurricane, Magis- names and type numbers of hostile planes, ter,Master, Roc,Skua, your increasing knowledge of friendly types Spitfire. will produce an instinctive sense of caution4. Flying Boats.-- Lerwick, when unfamiliar characteristics are noted. Sunderland. About Biplanes Let- us select as a conven- Do not-in the early stages, at least -ient example the mid -wing ri clutter up your mind by trying to memorisegroups of six machines.. The friendly biplanes and other relatively slownumber of engines is probably Armstrong Whitworth WH/TLEY training and transport planes.Many ofsecond in order of importance these, although at present doing valuableas a recognition feature. It Showing thearrangement of the fins and rudders of three distinctive work, are obsolete or obsolescent types.so happens that each of our types of aircraft They may be generally assumed to besix chosen types has two friendly.It is true that the German airengines.In the high -wing group we findlong slab -sided fuselage ;position of gun force includes large numbers of biplanes,examples of one-, two- and four-enginedturrets in the nose and tail; tail -plane is but as these are similarly employed formonoplanes, butthisusuallyvaluablenoticeably lower on the fuselage than that training and communication purposes, it ismeans of differentiationfails us in theof the Beaufort and Blenheims. unlikely that they will be seen in actionmid -wing group. We must, therefore, pass over Great Britain. If and when that occurs,on to the third important feature, theTwin Tail Types it will be an unmistakable sign that Goer-tail unit, which, we find provides this clear In considering the second group of three, ing's reserves have been sorely depleted. sub -division: what are the principal points of distinction ? (a) SINGLE FIN AND RUDDER.- Type of Engine.-The distinction between The first 24 Blenheim. Beaufort. Wellington. in -line liquid -cooled engines and -air-cooled Thefollowinglistof BritishService (b)TWIN FIN AND RUDDER.-engines may appear to be too fine, but in BLENHE/M MK/

(Left) Nose details ofthe Blenheim Mark I and IV BEAUFORT (Right) The Blen- BLENHEIIII heim and Beaufort have a strong family likeness November, 1940 NEWNES PRACTICAL MECHANICS 67 Join the Well -Paid Ranks of the TRAINED MEN THOUSANDS OF TRAINED WORKERS ARE The I.C.S. Offer Special Courses of Training in the following Subjects : URGENTLY NEEDED BY EMPLOYERS IN ALL Accountancy Highway Engineering Advertising Horticulturist PARTS OF THE COUNTRY. SKILLED MEN ARE Aeronautical Engineering Hydraulic Engineering Aero Engine Fitting Insurance BEING PAID EXCEPTIONALLY HIGH WAGES Aero Fitting and Rigging Joinery Aeroplane Designing Journalism Why not become one? You can. Agriculture Machine -Tool Work Air -Conditioning Marine Engineering Many I.C.S. Students have done Architecture Mechanical Engineering Architectural Drawing Mine Electrician so since war began-by means of Boilermaking Mine Fireman Book-keeping Mine Surveying a few months' spare -time study Building Construction Mining Engineering Building Contracting Motor Engineering Business Training Motor Mechanic The man who enrols for an I.C.S. Course learns the Business Management Moulder subject he studies thoroughly, completely, practically. Cabinet Making Patternmaking Carpentry Quantity Surveying We are not content merely to teach principles ; we Chemical Engineering Radio Engineering show our students how to apply that training in their Civil Engineering Radio Servicing Clerk of Works Refrigeration everyday work. We train them to be Colliery Overman Salesmanship successful-and we offer you the benefit Colliery Management Sanitary Engineering Commercial Art Secretarial Work of our 49 years' matchless experience. Concrete Engineering Sheet -Metal Work Cost Accountancy Ship Draughtsman Dairy Farming Steam Fitter If you need technical training, our adi1/2e on any matterDiesel Engineering Structural Steelwork Display Surveying concerning your work and your career is yours for the asking Draughtsmanship Telegraph Engineering Electrical Engineering Telephone Engineering -free and without obb:gation.Let us send you a bookletEngineer in Charge Television dealing with the subject iii ).'inch you arc specie//)' interested. Engineering Shop Practice Templating Fire Engineering Textile Designing It is packed with rathable information. DO N'T DI I 1. Fitter Textile Manufacturing lake " " your nyitchword. Forgeman Toolmaking Foundry Work Turner Garage Management Welding Thesuccessful man does today what thefailure Gas -Power Engineering Woodworking Ground Engineer Works Engineering INTENDS to do tomorrow. Write to us TODAY Heating and Ventilating Works Management COUPON FOR FREE BOOKLET (USE PENNYPENNY STAMP ON UNSEALED ENVELOPE) INTERNATIONAL CORRESPONDENCE SCHOOLS, LTD. Dept. 95, InternationalBuildings, Kingsway, London, W.C.2 Please tell me how I can become highly efficient in the subject I state below and send me, FREE of CHARGE or OBLIGATION, your Special Booklet.

SUBJECT (or EXAMINATION) NAME Age ICS ADDRESS 68 NEWNES PRACTICAL MECHANICS November, 1940 MAKE GOOD USE OF YOUR LEISURE at HOME in the BLACKOUT- INTEREST YOURSELF in the IDEAL HOBBIES- MODEL-MAKING and MODEL -OWNING

Here are attractive models for the long winter evening' -Railways, Engines,Ships. BUY NOW WHILE MONEY WILL BUY MORE, and while stocks are still available. NEW SEASON'S CATALOGUES include:- NEW GR. 12. Catalogue of Gauge "0" models, parts and accessories. Price 6d., post free. NEW TT.I2.Catalogue of the wonderful Gauge No. 6201. L.M.S. "Princess Elizabeth , " in gauge "0," L9 9 0 "00" Twin Trains. Price3d.,post free, New details like fit- 1 ting the steam dome AB.12 (1940) edition o to the rear of the top "SteamLocomotives. feedapparatus and StationaryEnginesand the new larger ten- Everything for the Model der are shown on this Constructor." handsome Gauge Price 8d.,post free. "0" model, L.M.S. "Pacific"which is available in clock- work,orelectric Set of L.N.E.R. Goods Vehicles-sec specolloPfer. THE EVENT d.c. or a.c. For furtherdetailsget OF THE YEAR G.R.12. a new editionofthefamous MODEL RAILWAY HANDBOOK Here is a special offer for the by W. J. Bassett-Lowke, M. floco.E. opening of the model railway MODEL SHIPS Priced at 3s. 6d. (postage 6d.) 150 season. Our standard gauge to build and run from our wide range of marine pages entirelyre -written with "0" steel plate goods model equipment.Anything from a miniature new illustrations-I60 half -tones vehicles at less than pre-war waterline "NORMANDIE" a few inches long and 40 line sketches - this prices. (and priced at 15s. post free for the set of parts is a Handbookeveryonein- Set LNE/O (asillustrated) illustrated) to a metre speed -boat capable of terestedatallin themodel 12 -ton L.N.E.R. Open Goods over sevenknots. Electric, clockwork and railway hobby should read. SEND Wagon. 12 -ton L.N.E.R. steam power units . . drawings .. . guns . . FOR YOUR COPY NOW! Covered Wagon, and 20 -ton dinghies ..kits of parts .. SEE THEM ALL IN L.N.E.R. Goods Brake Van. S.12 Model Ship Catalogue. Price 6d. BUILD A MODEL! Price complete 8s. 6d., post- Now is your chance for we have age 6d. placed on the market two fine Also GWR/O-similar set in setsof parts, with descriptive G.W.R.Lettering. booklets on same. Send for the ORDER PROMPTLY and se- book which interests you. Isit cure theseattractiveaddi-BASSETT-LOWKE LTD., NORTHAMPTON "Building a Bassett-Lowke Gauge tions to your gauge "0" line. 0 2-6-0 Mogul in 30 hours" or Sets on show at London andLONDON: 112 High Holborn, W.C.I.MANCHESTER: 28 Corporation St. "The Construction of a 21in. gauge Manchester - oravailable 4-6-2 Flying Scot" ? Each book- from Northampton 9!..post (Official Air Raid Shelters on all these premises) let 6d., "over the counter" or free. 8d. post free.

Keep warm with a PORTABLE ELECTRADIX TILLEY RADIATORRATE FIXING, PETROL ELECTRIC SETS lcprovides warmth in workshop, sitting -room, bedroom, etc. Burns for Lighting and Charging ordinary paraffin. No connections CJDTIME & MOTION Halfh.p. DIRECT COUPLED. or fixing.Absolutely safe. 150 watts D.C., 1,300 r.p.m.,2-stroke LIJ water-cooled 1-eyl. Engine, magneto Do notbedisappointedifyou STUDY, PLANNING, ignition. On bedplate with 30 volts cannot obtain prompt delivery of 5 amps. Dynamo. £13.75 Larger these famous Tilley Radiators. sizef kw. Petrol Electric Sets. F- 500 watts2- stroke water-cooled 1 h.p. Remember that, owingtotheir ESTIMATING, etc. 1 -mil.engine on bedmate direct - excellence, they are in great demand coupled to 50/70 volts 10 amps. D.C. by the three Fighting Services whose Hundreds of openings-in- Dynamo, magneto ignition, fuel and oil tank,S17/101-. requirements must come first. A few unused 1 h.p. and 2 h.p. al r -cooled engines on bed for direct teresting,well -paid work- drive, cheap. Steel forthe manufactureof Previous experience unneces- ELECTRIC AIR COMPRESSORS for Spray Painting and Tyre pum Vapourisersisdifficult to obtain. ing, coupled tomotor, 26/15/0 and OwnersofTilleyRadiators are sary-Our Guaranteed- 88/10/- A.C. or D.C. Foot -operated earnestly requestedto hand in " HomeStudy " courses Paint Spray Sets with Gun, theiroldVapourisers when A.C. MAINS LESDIX TIINGAR will get you in. CHARGERS. Two models.No. 1 for purchasing new ones from their Ironmonger. 70 volts 6 amps. with meters and con- Sold by all good Ironmongers -ed Stores. Catalogue from TheFREE 1940 Guide trol s, etc 400 cello a day,87/17/6. No. 2 Tungar for two 5 amps. circuits with TILLEY LAMP CO., HENDON, N.W.4. contains 12o pages of in- meters and variable volt controls, 70 formation of the greatest volts, 10 amps., for 200 cells, bargain, £121151-. importance to those seeking ROTARY CONVERTERS, all sizes, large and small, single-phase entry or advancement in and 3 -phase.Special Crypt° Constant Potential Charger, coupled to S.P. motor with D.C. output of Engineering.It gives full 8 volts 50 amps, and 100 volts details of salaries, openings 1 amp. Fine set, worth £50, with switchboard, sale 230. WIRE and prospects inDraughts- BARGAIN OFFER COPPERrdina POWER ALTERNATORS, H.F. At Hry Price manship. opportunities 50cycles, 20 amps., 10volts. Price per lb. for Double Cotton Covered. £3/10/..Ditto double, Type W. 28 SWG 3/8 32 SWG 4/8 36 SWG 6/4 inallother Branches of 500 cycles, 100 volts 3 amps. and 30 SWG 4/4 34 SWG 5/4 37 SWG 7/- Engineering includingAero 70 volts, 3 amps. D.C., P.5(1.01 - Price per lb. for Double Silk Covered. andGeneral Engineering RADIO ROTARY CONVERTERS. 28 SWG 4/4 32 SWG 5/4 36 SWG 7/8 For P.C. mains to 230 v. A.C. out- 30 SWG 4'8 34 SWG 6/- 40 SWG 12/- Inspection together with put. In silence cabinet, with filter, Posh/ye71. Redo and Winding 6d. per reef. All sizes in stock from 1.5 particulars of our special watts upwards. 30, 50,100, SPLIT PHASE A.C. MOTORS rapid courses and employ- ; 200, 400 and 800 watts; 1 kw. BastValuein England ment service and remark- 11 kw., etc. Also 50 -watt size, 1,425 R.P.M. All voltages. 12 volts and 50 volts input. able Guarantee of T.V.T. Sets, 6 volts to &C., Heavy duty rating. No radio interference.Silent SUCCESS-OR NO FEE 6/- EMERGENCY PARCELS of useful experimental running. Hightorque. electrical and radio repair material and apparatus, H.P., 75/-. I H.P., 85/-, Write now for your free copy of this re- 10 lbs. for 8/-. Post paid 1 H.P.capacitor,02/6. Stamped addressed envelope must be enclosed for ourlL. H.P. repulsion, 100/, markable publication.It may well prove BargainList"P.M."or reply to allinquiries. H.P. repulsion, 115/, to be the turning point in your career. Leitlets stamp SPECIAL OFFER. We have ELECTRADIX RADIOSa few H.P. machines. Rubber mounted, for 75/-, NationalInstituteofEngineering, 218 UPPER THAMES STREET, LONDON, E.C.4 L. WILKINSON, Guildford Place, High St., TAUNTON (Dept. 442) 148, Holborn, London, E.C.I Telephone:Central 4611 November, 1940 NEWNES PRACTICAL MECHANICS 69 practice the characteristic shape of either Tail Unit.-We have already noted thatdistinctive. type can be observed at an appreciablethese three machines have twin fins and WING POINTERS."The following distance. Each of the three machines pre:rudders, but here the similarity ends.It ischief points of difference are easily remem- viouslyconsideredisfittedwith radialour good fortune that each aircraft designerbered : engines. In the present group the Handleyappears to have a preferred shape and Lockheed-Hudson.-Wings fully tapered Page HAMPDEN has radial engines, butarrangement for fins and rudders. Theto tips; upswept from root to tips (dihedral it must not be forgotten that the Hampdenstudent soon learns to recognise this distinc-angle). Fowler flapsfittedtotrailing has a twin brother known as the Hereford,tive " signature."There are, nevertheless,edge. which is fitted with in -line Napier engines.occasions when an aircraft seems to out. Hampden.-Practically straight leading This point also enables us edge, fully tapered trailing edge.Wings to differentiate between the Vickers High fin and rudder upswept outboard of engines to tips. Mk. I WHITLEY, with radial WELLINGTON Whitley.-Large wing of low aspect ratio engines, and the more power- slightly tapered with square tips; upswept ful Merlin engined Whitley outboard of engines. Mks. IV and V. Undercarriage.-Thesix machines de- Considering fuselage,the scribed are all, without distinction, fitted Hampden is narrow and deep with retractable undercarriages. Only fair' forward, sometimes termed of the suggested first 24-the Bombay,Harrow, " aflyingsuitcase." The Lysander, and Magister-hate slender afterpart of the The Wellington bomber, which has a high fin and rudder fixed undercarriages.It is helpful to keel') fuselage serves chiefly as a boom, carryinggrow its designer's stock pattern, so that athis point in mind without placing too much the tail unit.The Whitley fuselageis machine which startsitscareer with areliance upon it as a means of recognition. long, straight, and slab -sided, with nosesingle fin and rudder may later develop twoOtherwise a temporarily lowered under- and tail gun turrets.In contrast, theor three. Conversely, a new type will takecarriage is apt to lead one astray. LOCKHEED -HUDSON fuselage is large,the air with three fins and rudders and sub- Concentration upon permanentstruc- deep,i'and of good streamline form, as may besequently be standardised with two or onlytural features is essential.When this is expected in a design developed from theone. combined with an orderlysequence of well-known Lockheed 14 air liner. There is For these reasons tail units repay par-observation, most of the difficulties which a domed turret on top of the fuselage, wellticular study, and each of the three underconfront the student of this absorbing sub- aft. consideration will be found to be quiteject disappear.

tiously abstracting the subscriptions of the Our Busy Inventors generous. By Dynamo Cute Names Americansdisplayconsiderable THEaptness in inventing names for their Rocking Air-raid Shelter Puddle Pump proprietary articles. The following are some significant current instances gathered THE latestthing in air-raid shelters willTHE hard tennis court tends. in time,from the official gazette of the United undoubtedly have a certain amount of more or less to resemble a switchbackStates Patent Office. sway.In other words, it is capable of arailway.It develops large dimples which, " Lilac Time " is the name bestowed upon swaying motion. Indeed it is nearly relatedon wet days, contain puddles. Expeditiouslyperfume extract, rouge and cold cream. to a rocking -chair.The new shelter has ato remove these tiny lakes is the object of a Radish Red " is apposite in connection convex under surface and is so arrangedrecent invention. The bottom of a bucketwith lipstick. that it will oscillate. The structure is loosely Explosives are well represented by the placed in a concave recess on the ground, The information on this page is specially supplied to term 'Tru-Shot." the recess having a larger radius than the "Practical Mechanics" by Messrs. Hughes & Youft '`Knee -Sense " is appropriate in relation bottom of the shelter. (Est. 1829), Patent Agents of 9 Warwick Court, High to hosiery. If a bomb explodes in the vicinity of the Holborn, London, W.C.1, who will be pleased to send readers mentioning this paper, free of charge, a copy " Tumble -Togs " is the name applied to shelter, the force of the explosion will of their handbook, "How to Patent an Invention." children's rompers. naturally cause the structure to rock within Youngsters' sleeping garments are desig- the limits of the recess.Consequently, it is provided with an opening communicatingnated " Snuz-Ease." will, more efficiently than a stationary " Automatic Memorizer "isthe name shelter, resist concussion from a direct hit.with a pump fitted within the bucket. Thisgiven to note -books. It will also considerably reduce the destruc-pump draws water through the opening tive effect caused by blast or splinters. Theand discharges it into the interior of the inventor claims that the shelter wouldbucket. New Toe -Tinter likewise afford protection from earthquakes. The invention is not only useful in keeping IT isfitting that a lady should devise The juvenile occupants of this wobblinga tennis court dry; it is effective in other improved means for tinting the finger refuge will be rocked in the cradle of theplaces where the removal of water by theand toe nails of the fair. shelter. usual methods is not possible or convenient. For example,it may be employed for As is obvious to all but the blind and the extracting water from the bottom of a tank.colour-blind, many modern damsels cause Long Life for Bristles the nails of their hands and feet to resemble " the roseate hues of early morn." To AHAIR brush, when not inuse,is Dummy Collector enable this colouring to be conveniently generally laid on its back and the comb performed is the object of an invention for is inserted in the bristles.The constant charming lady who stands at thewhich an application to patent inthis repetition of this action causes distortionTHEcorner of the street and with a winningcountry has just been made. of the bristles, some of which may eventuallysmile chinks a money box has an inanimate The device serves not only to protect be broken.This results in a groove orrival.And an application has been madethe hands and feet against the accidental irregular portion to appear, like long grassto patent in our land this dummy appellantapplying of tint or varnish to parts not which has continually been trampled upon.for charitable societies.There is a flat -intended. But it also provides a comfortable - Prevention of cruelty to hair brushes inbacking sheet bearing or being a representa-and easily supplied support for holding the this manner is the subject of an applicationtion of a person having relation to thetoes apart while the tinting is being carried to the British Patent Office. There has beenobjectfor which thecontributionsareout. devised a brush with a handle having aninvited.For instance, if it were for Dr. It comprises a member made of sponge elongated slot of depth sufficient to receiveBarnardo'sHomes,afull-sizedcurly -or cellular rubber.This contains holes for and retain a comb.Tapering of the slotheaded orphan would be pictorially per-the reception and separation of the fingers ensures a close fit,preventing the combsonified.Attached to the figure is .a bagor toes.The nails project beyond the from falling out. This device will contributewith a restricted. opening for the receptionmember to permit application of the tint. to the longevity of the hair brush. And theof coins. An inturned flap hinders the coinsAnd there areslits extending from the comb, assuming thatitwill always befrom accidentally making their exit. But -Iholes to one edge of the member, so that placed in its receptacle, will invariably bedo not, find any reference to means forfingers or toes can be removed without ready to hand. preventing unprincipled ft ,lt:s from surrepti-withdrawing them through the holes. 70 NEWNES PRACTICAL -MECHANICS November, 1940 MASTERS OF MECHANICS Huygens' ideas and experiments.in fact,hardest bones of beef itself and mutton he became a pupil of Huygens, assisting thewere made as soft as cheese, producing an latter in many of his experiments andincredible quantity of gravy, and a jelly collaboratingcloselywithhiminhismade of the bones of beef, the best for mechanical work. clearness and good relish ant the most delicious that I have ever seen or tasted." Expelled From France Practical Use of Steam Power However, Papin's association with Huy- gens did not last very long.Of a fervent Let us hope that all the early members religious nature, he held unpopular opinions,of the Royal Society who participated of and was, in 1681, expelled from France,Papin's "Digester" -cooked supper were of Dr. Denis Papin along with many other of his countrymen,the same opinion and were actuated by a as a result of a religious persecution whichlike enthusiasm.It would seem, however, IF any man is deserving of lasting fame inarose at that time.Papin took refuge inthat theyfailedtoseeanything very the annals of invention, such an indivi-London, where he came into personal con-remarkable in Papin's creation of the safety dual is surely the one who first applied totact with the celebrated Robert Boyle, withvalve, nor in the demonstrated fact that practical ends the fundamental idea of thewhose experimentshequicklybecamewater boils at a higher temperature under piston and the cylinder as a means forassociated. pressure than it does under normal con- generating power. During his sojourn in England, Papin tookditions. Denis Papin, a French physician of thean active part in the running of the then Papin's reputation as an experimenter of seventeenth century, goes down in engineer-newly founded Royal Society.He wassome daring and originality had extended ing history as the apostle of the piston andappointed a temporary curator of thatto Germany, with the result that he was cylinder.True it is that he was not theSociety at a salary of £30 per annum, andoffered a Professorship of Mathematics at first to conceive this nowadays universalwith the proviso that he should devise atMarburg, which appointment he accepted power -generating device.Nevertheless, itleast one experiment for demonstration atin 1687, and in which town he remained for was he who first took up the piston andeach meeting of that august body. many years. cylinder idea in his search for the secret of One of his first inventions of those days It was at Marburg that Papin made his steam power, and from his experiments the first experiments on the practical use of -and, perhaps, his nowadays best-knownsteam power.Huygens, we have already practicable steam engine directly followed.creation-washisfamous" Digester,"seen, had previously attempted to make a crude type of engine by exploding gun- powder in a barrel provided with a movable No. 6i.-A Physician Turned Mechanic, Dr. Denispiston, but Papin went one better by substituting steam for gunpowder. Papin's original steam engine was of a Papin, an Early Steam Power Pioneer very simple type. A small amount of water was placed at the bottom of a cylinder, which latter was then heated. The gener- Papin had a crowded career, which waswhich, to us moderns, is all the more note-ated steam pushed upwards a crude variety not without its romance, its glamour, andworthy because it embodied a very import-of piston.In the piston rod was a notch, its disappointments.Born in the Frenchant principle-that of the steam -pressure orwhich was engaged by a latch at the top of town of Blois, on August 22nd, 1647, he was" safety " valve. the cylinder.Thus when this latch was educated at the Jesuit school in that town Papin'soriginal" Digester "was anbrought into action, the raised piston could and was subsequently brought up to theapparatus for softening bones by boilingbe held in its elevated position. With the profession of a physician, studying medicinethem with water in a closed iron vesselpiston so held, the cylinder was allowed to both at Paris and at Orleans. under pressure.To obviate the risk ofcool. A vacuum was thereby produced explosion, Papin fitted in the upper portiontherein and thus, as soon as the piston Anaesthetics of his " Digester " a simple type of plungerlatch was disengaged, the piston was thrust When he was about twenty-seven yearsvalve, controlled by a lever from the end ofviolently downwards to the bottom of the of age, Papin settled in Paris, practisingwhich was suspended a weight. When thecylinder by the force of the pressure of the there as a doctor and gaining a considerableinternal steam pressure exceeded that of theatmosphere onitsexternalside. By reputation forhimself. He wrote,forweight,thevalve was raised,therebyattaching a rope to the piston, the rope instance, a Treatise on Operations With-allowing the steam to escape. In this guisepassing over a pulley, Papin found it pos- out Pain, in which work he described thecame the first germ-and application-ofsible to raise weights in this crude and use of various chemicals and drugs for thethe safety valve. decidedly erratic manner. purpose of deadening pain during surgical Papin's " Digester " served on one occa- operations.Here, therefore, at the verysion to cook a supper for the members ofRaising Water and Coal outset of his career, Dr. Papin is deservingthe Royal Society. John Evelyn, the famous Papin's cylinder had a diameter of 2 ft. of some little fame as a forerunner of thediarist, refers to the invention thus :" Theand a piston stroke of 4 ft.He suggested science of anaesthetics.Had he continued his medical careerin an uninterrupted Steam escape cock fashion, there is little doubt that he would Piston Filler cock have ended his days as a highly respected Elevatedcistern Paris physician, wealthy, tranquil, and well for boilers self -contented. But such a state of affairs had not beenPapin's final steam mapped out for Dr. Denis Papin.There Waterwheel happened at that time to be lecturing inengine by means of Paris Christian Huygens, the great Dutch which he proposed to experimenter, who had many inventions obtain motive power. and discoveries to his credit, among whichIt was unsuccessful was a primitive device for exploding a charge of gunpowder in a barrel fitted with an upwards -moving piston and so forcibly Water driving outwards the loose piston. Papin became very greatly impressed by Water trough November, 1940 NEWNES PRACTICAL MECHANICS 71 FOR MEN WITH IDEAS- TheMetalworking Outfit with the BIG IDEA behindit

SEE WHAT IT CONTAINS

THE INGENIOUS JUNEERO MULTI - PURPOSE TOOL plus SHEARS, SCROLL TOOL, SCREW CUTTING DIE plus Generous supply of plain and corrugated METAL SHEETS, STRIPS, RODS, ANGLE IRON plus NUTS and BOLTS, design sheets, manual, etc.

THE JUNEERO MULTI -PURPOSE TOOL

- SEE WHAT IT DOES WORKSHOP SET 1 PUNCHES HOLES

to take bolts a,Steel ships bee righr) ONE MODEL IS WORTH A DOZEN PLANS SHEARS Translate your ideas into metal-quickly-easily-permanently, with the aid strips and rodsto accuratelengths. of the ingenious and completely practical JUNEERO multi -purpose Tool, and (see left) JUNEERO materials. The new Workshop Set in handsome modern tool chest BENDS stripsto accurate nght angles with the JUNEERO Tool and a generous supply of JUNEERO materrals has orany otherangles required.Also bends been specially prepared for the industrial designer, inventor, handyman or rods (see right) THREADS RODS repairer.Price 601- complete. JUNEERO sets are also available at 151- and withtheaidof 301... Fresh supplies of materials available in11- packets from your Juneero Juneeroscrew -cutting die. (see felt) dealer.If any difficulty in obtaining your set, owing to war conditions, send remittance to us, adding1/- for packing and postage. (Abroad 516 extra). JUNEERO See and inspect DEALER Juneero Sets. Design COUPON: Write Name & Address in Margin LI= Sheets and Materials at your local Juneero Dealer. To JUNEERO LTD., Stirling Corner, Boreham Wood, Watford By -Pass, Herts. Please send me particularsofJuneero Sets and name ofnearest Juneero Dealer. NEWNES PRACTICAL MECHANICS November, 1940 AN ATTRACTIVE OFFER TO READERS OF"PRACTICAL MECHANICS" This 7 -Volume Movie Library PublishedII 7 6 at For only 13/9 The Biggest Bargain Ever Offered to Owners of Cine Cameras

All the books in this special offer ' are exactly the same as sold at doublethepricethroughthe usual channels. They are inno way a cheaper edition! THERE are many movie enthusiasts amongst readers of PRACTICAL MECHANICS-men and women who havealready produced good pictures with their cameras. The technique ofthe expert cameraman, however, may be acquired by practice and a careful study ofbooks writtenbytech- nicians for the ordinary camera user, and this 7 -volume library will enable you to produce films with the professional touch. Each bookispacked with information that will help you to master the tricks of the trade. Together they impart knowledgeyou couldnot easilygain by anyother means.

All orderswillbe dealt within strict rotation-but there isa set for every reader who applies within the next week or so.

FACTS AND FIGURES FOR THE FILMCRAFT. ADRIAN BRUNEL. The FILM PRODUCTION. ADRIAN BRUNEL. AMATEUR CINEMATOGRAPHER. technique of film production.Every step With an introduction by Alexander Korda. COMPILED BY G.P. KENDALL, B.Sc. Facts from thechoiceof subject to thefinal An important contribution to the study of and figuresrelating to exposure, effects, editing,clearlyexplainedbyanexpert. the film as an artistic medium. Deals with fades and timing, focusing data,filtering, Withappendices byotherwell-known art direction, treatment, continuity, casting, technicians.Price 3/6(for1/9,plus6d. titlelighting, timing, distances, animation direction, dialogue, make-up, set economy, postage). film editing, etc.Price 7/6(for 3/9,plus work, electrical and projection data. 6d. postage). Price 2/6 (for 1/3, plus 4d. postage). HOME PROCESSING. P. W. HARRIS, Order on plain paper if you do not wish to cut your copy of PRACTICAL MECHANICS. F.A.C.I.An expert'sknowledge of the FILM ACTING. PUDOVKIN.In this book fascinating business of developing and print- the famous expert discusses the relation ing movie films. How to print copies, pre- To PRACTICAL MECHANICS between acting and reality, film acting and pare films by the reversal method, tone and (Book Dept.), Tower House, Southampton Street, stage acting, and ways of overcoming the stain them, and how to make with simple London, W.C.2. apparatusthoseintriguing difficultiesof theprofession. Illustrated. "wipes" and Please send me by return the 7 -volume Film Price 3/6 (for 1/9, plus 6d. postage). "dissolves"whichare a featureofall Library for 13s. 9d., plus Is. 6d. towards postage, modern commercial films.Price 3/6(for making 15s. 3d. in all. 1/9, plus 6d. postage). FILM TITLING. G.P.KENDALL, B.Sc. I enclose Postal Order No Types of lettering, the use of home-made FILM TECHNIQUE. PUDOVKIN. A clear NAME and commercialtitlingoutfits,lighting, and concise exposition of the principles of exposure,animatedandtricktitles-all techniquewhich havemadePudovkin's ADDRESS comprehensively explained.Price 3/6 (for work avitalinfluenceinmodern films. 1/9, plus 6d. postage). Price 3/6 (for 1/9, plus 6d. postage). P.M. I 140 November, 1940 NEWNES PRACTICAL MECHANICS 73 that such anengine " should be employed been for the action of certain members of for raising water and coal from mines and the Royal Society in coming to his aid with for driving ships by means of paddles. small financial help, he would undoubtedly Also, by way of a faint foreshadowing of have ended his days in dire poverty. As it modern warfare,he suggested thatthe was, discouraged by his successive failures enginemightbeusedfor" throwing to construct a successfully working steam bombs," although he gave no indication of engine and by the prevailing lack of interest the exact means of so doing. in his projects, Papin surely hut slowly sank At alater date(in1707)Dr.Papin into an almost complete obscurity, from actually seems to have devised a paddle - which he never succeeded in raising himself. boat fitted with some sort of crude engine He is supposed to have died in London in as the one described above.Whether it 1712 (some writers give 1714; others 1710), ever worked even moderately successfully bet of his decease there is no clear record. we do not know. but it would appear that Of recent years the importance of Papin's the inventor made the necessary arrange- work in the evolution of the steam engine ments to transport his vessel to London in has been increasingly realised. The French order thatitcould be tried outin the nowadays claim Denis Papin as the origin- smoother reaches of the Thames. The story ator of the "atmospheric engine," thereby hasitthatthis remarkable vessel --the endeavouring to deny the claims of the progenitor of every steamship of modern British inventor, Thomas Newcomen. to times-was seized at Munden, a river town that honour. in Prussia. where itwas destroyed by a number of boatmen, who had heard vague A Mechanical Theorist accounts of its success and the ultimate Paphi, at first, as we have seen, a phy- promise of " sailing without oars which sician, and afterwards a physicist and a it held out. mathematician, was a mechanical theorist Although, perhaps, this story may be. in Papin's firststeam engine rather than a practical working mechanic. He had not the gift of mechanical construc- some respects, far-fetched, there is doubt- 'Thusit was that. Papin, whilst being full of less some truth in it, for, in the followingideas, made but littlereally sound andtion. Yet it is certain that it was Papin who year (1708) we have Papin writing ratherlasting progress with them. In some respectsfirst imagined a steam engine having a frantically to some of his old associates athe was a man born before his time. piston.It was he, also, who first saw that the -RoyalSociety,London,requesting Another of Papin's steam engine notionssteam could be used to produce a vacuum themtoadvancehimsufficientcash underneath a piston, which idea our own embodieda" displacementchamber "countryman, Thomas Newcomen, of Dart- Valve arm (analogous to a cylinder) containing water, upon the surface of which a piston or-mouth,subsequentlyelaboratedinhis diaphram floated.Steam generated in afamous " atmospheric engine," the world's boiler was made to force the piston down-first commercially successful steam power wards and thereby displace the water into anproducer.And finally, it was Papin, too, elevated tank. from which it was allowed towho first constructed the steam pressure or flow over a waterwheel.. " safety " valve, although, strange to say, This design of engine was unsuccessful,he- subsequently completely dropped the despite Papin's many efforts to improvenotion of this device. Screws clampmg down cylinc'e, upon it.In some respects, however, this Steam -power Device head engine represents a step -back from Papin's first steam engine, for the operation of the Dr. Denis Papin, therefore, must at least water -wheel engine was obviously evenbe accorded the honour of creating (or at more awkward and laborious than that ofany rateof conceiving) a steam -power Steam valv the first of Papin's engines.The steam,device in which the idea of the piston and after forcing the piston or diaphragm down-cylinder was first put to anything like hietal wards, was allowed to escape via a sidepractical use.But, as we have previously cylinder noted, Denis Papin was before his time, and cock, and subsequently the piston wasprobably for such a reason only he suffered raised to its original position in the dis-at the end of his life an ignominy and a placement chamber by means of a furtherdegree of hardship and disillusionment which supply of water being admitted therein. would have hardly been possible had he but It is a curious fact that, after originatingpossessedjustthatlittleextraability the idea of the safety valve with his famouswhich was necessary to push home his " Digester," Papin never applied the notionnotions to their successful conclusion and to to his steam engines. apply them in strictly practical fields. The original "Bone Digester- of Dr. Denis Papin.Papin Returns to England Itembodied theworld's firststeamsafetyvalve The above -described engine consti- DIESEL VEHICLES : OPERATION (approximately £15) in order that he mighttuted one of the last of Papin's essays in construct another engine " and fit it so thatsteam power. After the tragic failure of his MAINTENANCE AND REPAIR it might be applied to the rowing of ships."steam -propelled sailing vessel, he seems to The Royal Society, however, seems not tohave been thoroughly disheartened. Within By F. J. CAMM have acceded to this request. a short time, he left Germany and came Front all booksellers. 5s. art, by post 5s. (W. from over to England again. This time, however, the Publi,her: -Georg? Vewne, Ltd. (Book Dept.) Not a Great Mechanic he was not received with honour.Rather, Tower louse, Southampton Street. Ntrond, W.C.2. Despite the fact that Denis Papin was ahe was allowed to languish. and had it not fertile inventor, he was no great mechanic. He lacked the inborn ability to construct devices with his own hands. Always he had Hopeful Inventors to seek the aid of any workmen whom he couldfindtobringhis numerous and THE INVENTORSOF THE TANK ingenious ideas into actual practice.Ar-', of course, throughout his career Papin was EVEN in lease -time thereis a depart-which helped to win it.There were 1,834 faced with the severe difficulties of mechan- ment at the War Office which is keptapplications, out of which 544 were turned ical construction which were common toconstantly busy examining the indeas sub-down, 864 were abandoned by the inventors all inventors of his time.There were nomitted to them by hopeful inventors, but inand the remainder were dealt with by the metal lathes, no precise methods of drilling,time of war, the:trickle swells to a flood.Commission. grinding,screw -cutting,and machining.Literally hundreds of new inventions-and Altogether the Commission awarded a Each individual part of a machine had tosome that are not so new-are presentedtotalof i1,500,000 for inventions.The he made almost inconceivably slowly and,to the authorities every week. Perhaps onemost involved case of all was that of the with the utmost labour, by hand, and, oftenin a thousand is any good. tank, for which there were 8:5 claimants. enough, when a number of mechanical After the last war a Commission was setThe Commission reduced this number to parts came to be assembled. they would beup to make awards to those Ito had in-two-SirWilliamTrittonandMajor found not to fit. vented or claimed to have invented ideasWilson-and they received £15,000. 74 NEWNES PRACTICAL MECHANICS November, 1940 "MOTILUS" PEEPS INTO THE

A view of Mr. L. Hertz's 2'/8 -inch standard gauge railway. Note the realistic and sinple detail on cars and engines ACOUNTRY that is making enorm-his gaze from the world at large to studyMr. Robert Clark, and is the modern cruis- ous headway to -day --as far as onethe lines of a beautiful yacht, and here weing and racing yacht, Mary Bower.It is can judge from correspondence andare able to show you both the model andmodelled to the scale of -8-in. to the foot, magazines and books on the subject-inthe original.All designers should be proudwith dimensions of 18 in. in length and 4 in. model railway production,is the U.S.A.of the yachts they design, but often afterbeam. It will be noted that the model Anyone who reads the journals of our friendsthey have finished a yacht it passes out ofshows the standing rigging, but no running across the Atlantic will realise the advances that are being made, chiefly, of course, in electrically operated and controlledrail- ways. There is no doubt that the enormous Model Yacht and Model Power Boats exhibition -the World's Fair at New York last year and again this year-has beentheir hands and that is all the impressionrigging or sails.The fittings are all silver instrumentalin showing models tothethey have to remind them of their work.plated, with beautifully polished hull and general public who previously had no idea ofBut when a model is made, there is a recordbase and the model will he protected by a the scope of the hobby, and has kindled aintangible form.This model, which is ofmahogany show -case and, when mounted brighter flame of interest in the hearts ofsuper -detail finish, has been built for theunder glass,will be a real pleasure to those who were already model minded. owner, on the instructions of its designer,examine as a fine example of the cruising One of my friends in New York, Mr. Louis Hertz, a contributor to many American model journals and editor of the " Model Railroaders' Digest," has recently mailed me a photograph of his 2 On. standard- gauge layout,giving some idea of the realistic scenic effect he has produced. The background is partly painted and partly real, some of the trees, station, etc., being actual units and not painted as are the trains to the back.Mr. Hertz writes that the actual equipment in this picture is of rather early vintage-Lionel 1910, to be exact. He has about the largest layout in the U.S.A., and upwards of 200loco- motives, but when this particular picture was taken it was desired to show some of the old equipment at the same time. He writes that " this layout has now been taken down ready for moving, and when I set it up again L think the trains on the background will best be left off the painted wall ! " A Model Yacht Even the most casual onlooker will shift The power plant of an American model enthusiast's motor boat November, 1940 NEWNES PRACTICAL MECHANICS 75 MODEL WORLD

yacht of to -day. Model Power Boats Another friend of mine inthe Middle West of America-Minneapolis to wit-has further favoured me with some pictures of A recent picture oi his work-this time of model power boats. Bassett-Lowke's He writes : " I recently had the idea of fixing up an old concretefishpool and shop in High Hol- taking some pictures of my tests on model born steam boats.I put the pool into good con- dition and then began inspecting my models which I had not run through for about ten years !I found they were not good enough to kick up enough spray in the pool to appear impressive in a picture, so am now in the throes of fixing up their engines. " My first picture shows the power plant of one of my boats. The engine is a Stuart Turner. which I bought as castings; theadvertised in the papers, givingmy tele-started and told me exactly where T could boileris ofShelby 'seamless steel tube.phone number. Next morninga phonefind her ! " Model Display Walking along Holborn the other say, was pleased to see, despite the aerial bom- bardment of London, that Messrs. Bassett- Lowke ale making an excellent show, even in wartime. They must have had a splendid reserve of their best models in stock before war broke out, to enable them to make such a good display of specialities after over 12 months of war. In addition to their own productions, they were showing the " Studiette " sets of parts and lines, new flying construction kits, including the Spit- fire and Hurricane fighters and Wellesley bombers. and the German Messerschmidt fighters.Bassett-Lowke's London shop was first opened in 1909 where the Pearl Insur- ance offices now stand. Not long afterwards they moved to 112 High Holborn, where they have been for nearly thirty years, the land- mark of England's model world. They carried on in business throughout the last war and are hoping to do the same in this with the help of such papers as " Practical Mechanics," which still forms an invaluable link between model makers, who have been scattered for various reasons all over the country, and not forgetting those abroad with whom they still hope to maintain trade. THE LEADING WEEKLY FOR (LA The "Mary Rower" cruisin, yacht prototype(Right) a super detail scale model of the "Mary Bower" ENGINEERS which 1 cut to my own ideas and then hadmessage came through fromawoman who PRACTICAL ENGINEERING welded together.Cross tubes in the flametold me the boat had been found on the 4d. Every Thursday tube were expanded by a method I workedshore across thelakefrom whence she out myself, but which nevertheless was perfectly satisfactory. The blow lamp was bought ready made, and the frame on which the boiler and engine are mounted was constructed mostly from 1 -in.Shelby ' tube. " The second picture shows my' brass boat,' so called because the hull is of that metal, towing two of my very crude earlier models. The shore in the distance is about half a mile away. RPhis boat had one inter- esting adventure.She was running, in a very large circle rather too late in the even- ing, and the blow -lamp died from want of petrol. By the time I went around the lake.

where I could secure one of the row -boats , they rent, it was too dark to even dream of fofirsior.sorp-sr. finding her. There was not very much wind. but as there was a very small leak in her hull,I feared that she would sink before she drifted to shore. Next morning she was nowhere to be seen and I felt sure she had sunk.1 made a ' water telescope ' and went out in a boat and looked for her on the bottom.butwithoutsuccess. Then I The "brass boat" of a Minneapolis correspondent towing two other models 76 NEWNES PRACTICAL MECHANICS November, 1940 Watch Repairing and Adjusting-No.11 Watchmaker's Tools

hands,cuttinghair- springs, etc., are shaped"' like pocket nailclip- pers. For straightening pivots the points are flat and wide.Non- magnetic tweezers are Watchmaker's lathe and some of the split collets and stepped chucks made of brass.Prob- ably the most useful of THE skilled repairer can never havethe whole range are those for holding small too many tools. A large and variedpieces like pallets and those for removing selection gives confidence and enablespressed -inhairspring studs. The latter any repair to be undertaken. consists of a lower jaw, forked to embrace As a watchmaker's kit can be extensive,the stud and an upper jpw with a small pivot. I will deal with the smaller bench tools first.When depressed the pivot pushed out the The inability to hold an eyeglass in thestud. Hand -riveting traditional manner should be no cause for Apart from tweezers, the screwdriver is stand, stake and despair.If the old method of attaching aprobably the most used tool. Pocket screw- piece of elastic to the eyeglass does notdriverswith interchangeablebladesare thimble appeal, one of the modern methods can beconvenient, but for bench work the fixed used.One method consists of a pair ofblade is best. Some of the best screwdrivers spectacle frames to whichisriveted anare London made and can be obtained in a independent lens which can be brought intorangeofsizes.Thesizesrange from immediate use. To wearers of spectacles0.75 mm. to 2.75 inns.Although not a this is a boon as the frames can be glazed toscrewdriver, the balance screw adjusting personal prescriptions.The latest devicetool serves the same purpose. This tool has consists of a collapsibleeyeglass with atwo jaws which are closed by means of a monocle type of rim which can be slipped over shell or other kinds of spectacles.

This type is a miniature counterpart of the old-fashioned bench vice with iron leg. One model has a hollow handle.This is very convenient as it enablesa longpiece of wire to be held, thereby saving time in centring short pieces.Other hand tongs are made on the plier principle with a variety of noses.Some aredesignedforholding Various patterns of tweezers watch hands. Hour hands are held in jaws Many types of ordinary eyeglass areknurled nut.The ten sizes range fromwith holesinto which the sockets are available. Those suitable for general bench.20 mm. to .80 mm. placed.Minute hands are held in jaws work are made from celluloid, vulcanite or having a fine slit. horn. These are light and comfortable but Nipper and plier designis even more ar2o varied than that of tweezers, for each type will fracture if constantly dropped.For strengthuseeitherrigidorcollapsible can usually be supplied in at least four aluminium. The only disadvantage to this differentlengths.Watchmakers' nippers type is that constant use tends to make a Die -jawed tweezers for forming Bregnet hairspringsare made in as top or side cutters. black mark on the face. The folding patternPin -Tongs Pliers and Files is really only suitable for the pocket. Dual Other adjustable tools of similar design Pliers can be supplied with short cad long control eyeglasses consisting of two lensesare commonly called pin -tongs. Some are are useful for examining jewel holes and tiny flat,short and long round, half -round, single, others double -ended.The single -pointed,brassjaws,parallelandself- working parts. Mention must be made ofended type consist of a brass or wood handle,adjusting jaws.Others have special jaws the dual eyepiece microscope now provinga four -jaw chuck, and a knurled adjustingfor balance trueing, adjusting hairsprings popular in the detection of escapementnut. Another type is known as the pin vice.when fixed to balance, hand and collet faults. remorina. watch case adjusting and braee- Types of Tweezers Tweezers are one of the watchmaker's most useful tools, and are made in more than thirty different styles. As well as general purpose tweezers which are made with fine Various types of peers. points in a variety of patterns, there are (Lefttoright)Long tweezers designed for special purposes. For nose, half round, round taking movements apart the points are nose,taper nose,wide curved like a bird's beak. As well as extra nose fine pointed tweezers for hairspring work are a number with hollow jaws for Bregnet hairspringwork. ForcoilingBregnet springs some jaws are fitted with adjusting screws. Nipper tweezersfor taking off watch November, 1940 NEWNES PRACTICAL MECHANICS 77 let fixing. Two kinds of punches are avail- to the upper endf the gauge. Movement able. One for removing broken screws and of the steel shaft naturally moves the lower one for punching holes in mainsprings. The jaw. The distance of the pivot from the mainspring punch can be supplied with one nose-which represents the bottom of the punch or from different shaped punches cylinder-is therefore registered between and a barrel hook punch. Screwdriver availableinvarious blade widths the two jaws. When the jaws are closed the A good file is a valuable asset ; a good pivot is flush with the nose. selection of files is even better. Flat files are called pottance and pillar, the only differ- Barrel Arbor Gauge ence being in the width. Made in differentle4-2,14 The size of a barrel arbor is designed to lengths and at least half a dozen different be one-third of the inside diameter of the cuts, perhaps the most important feature is Pin vice barrel. In order that the exact size may be the safety edge. One edge has no serrations, determined when fitting a new arbor, use thus enabling one side of a right-angle to be should be made of a barrel arbor gauge. filed without damage to the other. A set of The gauge consists of a pair of calipers watchmakers'files,escapement files and having inside jaws at one end and outside needle files is a joy to any repairer. Although jaws at the other. The inside jaws of these their life is short owing- to their delicacy proportionalcalipers always open three the delight in using themisworth an times the size of the outside jaws. occasional break.In all these files, three Hand vice quarters of the length is handle. The shapes Calipers include flat taper, flat oval, three -square,gauge have curved jaws at the pivoted end Calipers are usually used for measuring, square, round, half -round and knife-edge.and a pointer and scale at the opposite end.but several different types are made, a No bench can be said to be complete withoutPinion Gauge number of which are used for testing the a screw -head file, sometimes called a slitting truth of wheels.In some fine holes are file.This is a thin blade of steel having The pinion gauge which is used to takedrilled on the inside of the jaws, in others serrations on the edge only. theheightof pinionshoulders,closelyjewel holes are fixed. A small movable Broaches, the five -sided reamers used byresembles the bow pen used by draughtsmen.toucher or feeler is attached to one arm. watchmakers, can be bought separately orThe two slender jaws are opened or closedThis feeler is brought near the wheel being in assortments. Sizes are gauged on Stubs'by means of a screw. The pinion heighttested.Any unevennesswillthen be wire gauge, from 1 to 80. The smaller sizesgaugeisa smallscrew -operated gaugereadily detected. The plier-shaped caliper are called pivot, pallet, joint and bottoming broaches. Round broaches, which can be obtained in the same sizes, are used for burnishing and hardening the surface of brass holes. Oil Containers Oil cups or containers consist of a box- woodstandwithaconcavecornelian reservoir. Some have two reservoirs, one above the other for different oils. The most up-to-date is a small stand like an inkstand with various containers and reservoirs and a place for oilers which is supplied by a well-known firm of. oil manufacturers. Gauges are essential items of the watch- maker's kit.No accurate replica can be made without a gauge. The most used are probably the two mainspring gauges. The (Left to Right) Balance poising calipers. Martin height gauge is a double -sided brass The middle finger checks lateral truth gauge.Notches corresponding to various of balance.Tool for cleaning, truing widths or heights are cut on each edge. and switching bezels.Doujieme gauge Lever sizes on one side and Geneva sizes on for thickness, staff height, etc. the other. The mainspring strength gauge- for gauging the thickness of the spring-whose extremities end in two small feet.is one of the most popular on the market. consists of two pieces of steel with a taperingThe feet are extended until they touch theSpring controlled, the plier is fitted with an space between. A space is provided at theinside of a pair of jewel holes. This measure-adjusting screw, feeler, male and female top to enable the mainspring hook to bement is recorded on two fine jaws at thecentres. passed through when gauging a spring. other end of the gauge.The recording A pivot gauge which has been describedfeetareslender and curved to enableRebushing Bearings in a previous article is similar to a main-measurements to be takenin deep set spring height gauge. The micrometer is toobridges and plates. When rebushing a brass bearing,itis well-known to need any description.For When replacing a broken cylinder use isessential that its position with regard to the measuring balance and otherstaffsthemade of a cylinder height tool. The smallother wheels should be correct. To ensure douzieme or dixieme gauge is used. Thesetubular gauge has a movable central steelthe correct depth, the wheel whose bearing gauges are divided into twelfths or tenthsshaft. The upper end of the shaft terminatesis to be bushed and the next wheel should of a ligne and are particularly suitable forin a jaw, the lower end of the shaft ter-be placed in the depthing tool.This tool measuring the overall distance from jewelminates in a pivot, small' enough to enterconsists of two sections, pivoted, spring hole to jewel hole.The two limbs of theany jewel hole.Another jaw is attachedcontrolled with an adjusting screw. The adjusting screw allows the sections to be opened or closed. Each section or side has two tail stocks with adjustable runners. The inside ends of the runners have female centres and the outside ends male centres. A pair of wheels or a wheel and pallets being tested areplaced betweenthefemale centres and the depths adjusted. When the depth is correct, one pair of runnersis released and the wheels removed. The male centres are then used to trace (Left) Swiss pattern bow -operated the correct position on the watch plate. turns, usedfor pivoting, etc. One centre is placed in the existing bearing, (Above) Many types of eyeglass are the other centre is brought to the level of available. Those suitable for general the watch plate and a portion of a circle benchwork are made from celluloid. described by slowly revolving the watch vulcanite or horn plate. 78 NEWNES PRACTICAL MECHANICS November, 1940 of the screen would give sharper definition than transmission through the granular . texture of ground glass. In any case much must not be expected QUERIESQ.4 from such a make -shift substitute for a proper camera obscura,if onlyfor the reason that your telescope object glass is so small. Magnified representations of -C\, ENQUIRIES things need brilliant illumination of the originals, and the relatively feeble radiance of the sky has therefore to be concentrated A stampedaddressedenvelope,threepenny stamps, and the query coupon from the current for satisfactory projection. This entails issue, which appears on page iii of cover, must be reduction in the size of the picture, as on enclosed with every letter containing a query. Every query and drawing which is sent must bear the ground glass screen of a stand camera. the name and address of the reader. Send your In fact, such a camera, if of half-plate size Silver Plating queries to the Editor, PRACTICAL MECHANICS, would about give you what you require. CAN you give me a formula for a liquid or Geo. Newnes, Ltd., Tower House, Southampton If you could get hold of a second-hand paste (not using mercury) for silver Street, Strand, London, W.C.2. telescope object glass of two or three inches plating small articles of copper and brass? diameter, you would obtain much better I should like the result to be permanent if TELESCOPE withitsinternaldia-resultsthanwith yourone -inchlens ; possible.-A. H. (West Ealing, W.13). AAphragms and compound eyepiece wouldmoreover, the longer focus would give you THE following is a formula for a silver-be unsuitable for projecting an expanse ofa larger image. platingpreparationnotcontainingsky on to a screen.The region magnified mercury : would be very small and dim.Moreover. Vulcanised Rubber Silver chloride .. 6 oz. even if a plane happened to cross this CANyou recommend any solvents Tartaric acid .. 12 oz. limited area it would not be perceptible for dealing with vulcanised rubber ?Pro- Common salt .. 6 oz. more than a moment.A better cameracessing is no objection, provided the liquid Chalk .. 4 oz. obscura effect would be obtained by usingis reasonably cheap and easily handled.- The above ingredients in a thoroughlythe object glass alone.This could be doneW. L. (Surrey). dry and powderedconditionarewell by leaving it in its section of the telescope is not easy for us to answer your query mixed together. Sieve the mixture throughtube and disconnecting the others; pro-ITfully because you do not state to what a finesieve and store the powder ina vided that that section does not containdegree your rubber has been vulcanised. perfectly dry amber -glass bottle. any diaphragms, orthatthey canbeUnvulcanised rubber, as, no doubt, you are In order to use the preparation, takeremoved.Alternatively, the object glasswell aware,isfairlyreadily solublein sufficient powder for the work in hand andmay be left in its cell and firmly remountednaphtha, carbon bisulphide, ethylene di- mixitwith sufficient water to form ain another short tube (cardboard, fibre orchloride,sulphurmonochloride,whilst sloppypaste.Apply this paste with ametal) taking care that it is set accuratelypetrol and petroleum -naphtha will usually perfectly clean rag to the well -cleaned andsquare. You would have to find some wayswelloutunvulcanisedrubberwithout grease -free metal surface, rubbing vigor-of supporting this tube in such a manneractually dissolving it. ously until the desired degree of plating isthat it could move in all directions, unless If, however, your rubber is " dead hard obtained upon the metal. Afterwards rinseyou are satisfied to hold it in your hand orvulcanised, it will be more or less completely the plated parts with warm water and allowto fix it rigidly in the wall or roof of yourinsoluble, although, to a certain extent, it them to dry.It is often advisable to give pill box. The screen would have to bemay be softened by prolonged immersion the plated areas a thin coating of clearattached to the tube by a light frame andin tricresyl phosphate, dibutyl phthalate, lacquer after this treatment. placed at a distance from the lens of aboutthese solvents being employed in the pure its focal length. There should be some slightstate or mixed with an equal bulk of Preparing Chamois Leather freedom to slide up and down the tube fortrichlore thylene. WHAT isthe best method of makingfocussing purposes. A smooth white paper Partially vulcanised rubber can usually chamois leather out of lamb skins ?or cardboard reflecting surface on the insidebe got into solution by soaking and macera- -W. H. (Co. Tyrone). ting in any of the solvents mentioned in will, we are afraid, find it a difficult the first paragraph. After solution has taken Youmatter to prepare chamois leather from place, it is a good plan to add to the liquid lamb skins, since, in the manufacture of THE P.M. LIST OF BLUEPRINTS about 1 per cent. of tricresyl phosphate or this material, much depends upon practical dibutyl phthalate to preventgelling " of experience. However, you may go about the F. J. CAMM'S PETROL -DRIVEN the solution. MODEL AEROPLANE job in the following way : 7s. 6d. per set of four sheets, full-size. All the solvents mentioned above are Soak the skins for two or three days in The 'PRACTICAL MECHANICS" C20 CAR fairly cheap, particularly when bought in cold water, after which immerse them in a (Designed by F. 1. CAMM) bulk from suppliers such as Messrs. A. thin cream of lime and water for a further 10s. 6d. per set of four sheets. Boake, Ronerts & Co., Ltd.Stratford, "PRACTICAL MECHANICS" MASTER London, R, but they must be handled with ten days. This treatment will loosen the BATTERY CLOCK hairs and enable them to be rubbed out with Blueprint Is. care, since some of them are inflammable the aid of a blunt knife. Again rinse the The "PRACTICAL MECHANICS" OUT- whilst others are toxic. skins in cold water so as to remove all the BOARD SPEEDBOAT 9 9. 7s. 6d. per set of three sheets. " Acetyl Chlorine lime, and finally immerse them in a bath A MODEL AUTOGIRO containing egg yolk, flour, common salt, Full-size blueprint, Is. has recently been a good deal of and alum. SUPER -DURATION BIPLANE THEREpublicitygiven' in the American and The exact proportions of these materials Full-size blueprint, Is. English Press concerning the use of "acetyl used by chamois leather makers are kept The P.M. "PETREL" MODEL chlorine" as a sleeping gas for use in war MONOPLANE secret, but there is little doubt that if you Complete set, Ss. time. Could you give me any details of the make up a thin cream of these materials to The I c.c. TWO-STROKE PETROL ENGINE chemical and physical properties of this soak the skins in you will get reasonable Complete set, Ss. compound and how it would be used for results. STREAMLINED WAKEFIELD the above purpose ?-A. F. M. (Folkestone). The skins are soaked in this bath for MONOPLANE -2s. THERE is no such substance as acetyl anything from a fortnight to three months, A LIGHTWEIGHT GLIDER chlorine "and we fearthat any after which they are carefully washed in Full-size blueprint, 2s. MODEL DURATION MONOPLANE reference to this must constitute still another clean water, and air-dried. Full-size blueprint, 2s. of the many technical inaccuracies of the If the skins are hard they can be softened WAKEFIELD MODEL newspaper Press. by rubbing egg yolk into them and finally Full-size blueprint, 2s. Are you, however, perhaps, thinking of washing it out. FLYING" LOW -WING PETROL MODEL acetyl chloride ?This chemical, which has PLANE Full-size blueprint of wing sections, 6d. the formula CH,.COC1, is a liquid, made Aircraft Spotting LIGHTWEIGHT DURATION MODEL by the action of phosphorus trichloride IS it possible to obtain a clear image on an Full-size blueprint, 2s. upon acetic acid.Itiscolourless and 8 in. by 8 in. ground glass screen through P.M. TRAILER CARAVAN pungent -smelling, fuming in moist air. It is a telescope which is focussed at 17 in., with Complete set, 10s. 6d. not, however, of much military use,, since or without extra lenses?I wish to fit the The above blueprints are obtainable post free from it is rapidly decomposed by moist air into device in a concrete " pill -box " for aircraft 3 Messrs.G.Newnes,Ltd. TovverHouse Strand,W.C.2 acetic acid and hydrochloric acid, both of spotting. --J. S. (Wembley). LammOOOOO 111111.1110111111...which are easily neutralised.Furthermore November, 1940 NEWNES PRACTICAL MECHANICS 79 it does not possess lethal or " sleeping a damp rag over the mouth and nose. ThisSteward Street, Springhill, Birmingham, or properties. will act as a satisfactory fume catcher. The British Transfer Printing Co., Ltd., You may, alternatively, be referring to If, for any reason or other, you feel thatQuinton Road, Coventry. carbonyl chloride, COCl2, a gas which mayyour system has imbibed more chromium Most transfers nowadays comprise, thin be obtained by the direct combination offumes than is good for it, take a purgativefilms of toughened gelatine laid on paper and carbon monoxide and chlorine and which isand several cups of strong tea. Such a pre-suitably printed upon. To make them, pre- extremely poisonous and lethal and hencecautionwill prevent traces of absorbedpare an approximately 15 percent. solution of value in military gas operations. Carbonylpoison from settling in your system. of hard gelatine in hot water, and flow this chloride is generally known as " phosgene." There are no special regulations respectingevenly over the surfaceof thin,well- It smells like musty hay and when breathedthe individual use of chromium -containingcalendered 'paper.Next, pass the paper in even moderate concentrations quicklyalloys in welding. You are probably think-(after the gelatine film) has set through a brings on unconsciousness. ing of the several Regulations designed tohardening bath containing one part of We cannot think of any other toxicprotect workers in the chromium -platingformalin in 100 parts of water. Allow the substances which may be referred to underindustry, which is, of course, a dangerouspaper to dry, and then print on it. Another the name of " acetyl chlorine," but youoccupation if the necessary precautions aresheet of paper is now taken, passed through may take our word that no such materialnot taken. a sizing bath of gelatine or arrowroot starch as the latter -named exists. and dried. The transfer sheet is wetted and Making Match Heads laid down in contact with the sized paper, Resistance for Arc Light CAN you give me a formula for makingthe printed gelatine surface of the former I HAVE an arc lamp movement belonging match heads that will cause as littlebeing pressed into contact with the latter. Ito a full-size cinema projector, and asmoke as possible ?-L. M. (Monteith). After a few minutes, the top paper support variable resistance which I think was used COMMON friction matches can be madeof the gelatine film can be stripped off, for lowering theatre lights.Can I run this by dipping wood chips into a pasteleaving the printed gelatine film adhering to arc with the resistance off the house lighting?made up by grinding together red phos-the sized paper support. This is the transfer The installationiswiredfortheall -inphorus, manganese dioxide and a smallrequired. For use, itis wetted, squeezed system and the meter will take 50 amps.-amount of potassium chlorate with a thickfirmly on the surface to which it is desired to K. 0. (Manchester). solution of glue. If required, the manganesemake the transfer and the support paper is WITHOUT knowing the normal currentdioxide can be omitted from the formulathen stripped away, leaving the transfer consumption of your arc lamp, andand the quantity of potassium chlorateattached to its new and permanent support. the resistance in ohms and gauge of wire inincreased. When dry, matches so preparedFinally, the transfer is varnished over with your dimming resistance, it would be impos-will ignite on friction with any rough sur-a thin, clear varnish. sibleto give a definitereply to yourface. question. As a rough guide, the normal Safety matches are prepared by dippingHome-made Toothpaste current consumption of your lamp can bewood chips into a mixture of equal parts ofI HAVE made what Iconsider a satis- estimated by the size of carbons it employs.antimony sulphide and potassium chlorate, factory toothpaste bymixingprecipitated The normal carbon diameters for varyingfinely powdered and made into a paste withchalk with a flavouring mixture. Would it current values are :- thick glue solution. Such match heads, afterbe advisable to manufactureit ?-D. M. For 6 amperes, carbon diameter of 8 mm.drying,will only ignite when they are(Manor Park).

12 ,10 rubbed on a surface which is covered with a AS far as it goes, your toothpaste is quite 24 mixtureofredphosphorus(3parts), good, but, in our opinion, it does not go 48 ,,15 powdered glass (1 part) made up into a pastequite far enough. As the terminal voltage of a normal A.C.with glue solution. Itis more or less the general opinion arc is only about 35 to 40 volts under normal If the matches so prepared give rise to toonowadays that a dentifrice made up entirely burning conditions, the series resistance willmuch smoke, slightly increase the potas-of chalk is rather too abrasive for the teeth. have to dissipate something like 200 voltssium chlorate content of the various mixtureIt would be better, therefore, if, instead of when carrying full current, the requiredand cut down the proportion of glue. usingprecipitatedchalkentirely,you value in ohms being 200 divided by the employed 50 per cent. of chalk and 50 per amperes taken by the arc. Probably a step-Making Perfumes cent. of light magnesium carbonate. This down voltage transformer would be found CAN you tell me how I can extract oil ofabrasive mixture should be " diluted " with far more economical if the lamp is to be in peppermint from the plant?If so, howa substance such as ground orris root, and it use much, with just a few ohms in circuitmuch oil can be obtained from 1 lb. of pep-should also contain a small percentage of as a steadying or ballast resistance. permint, and what apparatus is necessary ?soap and also a small percentage of pow- Will the perfumes sold by chemists sufficedered gum myrrh to act as an astringent for Welding Stainless Steel for the preparation of perfume pastilles ?-the gums. WHAT precautions should a welder takeF. 0. (Royton). There are many difficult formulae on the toavoidinhalingthefumesof IN order to obtain oil of peppermint, theabove lines, a typical one being the follow- chromium when welding stainless steel? Also, flowers and leaves of the plant (eithering :- is it necessary to take any precautions whenfresh or dried) are macerated with a small Precipitated chalk 50 perParts welding electrodes containing 8 per cent. orquantity of water for Several days and then cent.` .. more chromium, and are there any Board_distilled. A mixture of water and pepper- Light magnesium carbonate of Trade regulations to this effect?-T. B.mint oil passes over. The oil is separated 50 per cent. .. (Lincs.). from the water and re -distilled. Powdered orris root .. 15 r`HROMIUM is not a volatile metal.It Only a simple type of still is required for Powdered gum myrrh .. 5 boils at a temperature of about 2,200the production of the oil, but unless the task Best Castile soap powder . 5 degrees Centigrade.Hence, when weldingis carried out on a very large scale itis stainless and mild steels with electrodeshardly worth attempting, except by way of 100 containing chromium, one is not likely tointerest.About 1lb. of the pure oilis inhale any actual chromium metal vapour.obtained from some 250 to 300 lbs. of the The above ingredients may, of course, be Some of the chromium metal, however,plant. varied to suit your individual preference. oxidises at the high temperature to which The perfumes sold by chemists will sufficeFor instance, if a more " foamy " toothpaste itis subjected during the welding opera-for the preparation of the perfume pastillesis required, the percentage of soap powder tion, and, owing to a. sort of " spluttering-"you mention. Avoid, however, the lightermay be increased. effect, the chromium oxide thus formedperfumes such as eau de Cologne.It is The above toothpaste powder will, of passes off into the air in the form of anbetter to use the heavier perfumes and, ifcourse, have to be flavoured.For this extremelyfinespray. This emanationpossible, actual essential oils, such as oil ofpurpose the best flavourings are oil of should not be breathed in any quantity,cinnamon, oil of lavender, etc. peppermint and a trace of oil of wintergreen for all chromium compounds are more or (methyl salicylate). A judicious mixture of less poisonous. Transfer Making these two essential oils freshens up the Short of wearing a simple form of res- I Sitpossible to make satisfactory andtoothpaste flavour remarkably and leaves a pirator, or even a moistened cloth worn over reliable transfers at home ?-D. H. (Isle -" clean " taste in the mouth. the mouth and nostrils, there is little oneworth). We do not think that the toothpaste as can do to avoid inhaling small traces of YOU will find it an extremely difficultyou make it at present would stand much chromium fumes when engaged in these matter to make satisfactory and reliablechance of success on the market, but made jobs. Whenever possible, always carry outtransfers at home, and we would advise youon the above lines and suitably flavoured, the job in the open, or, at least, in well -to procure such articles from any firm ofattractively got up and, of course, adver- ventilated surroundings. If the job has totransfermakers andprinters,as,fortised, the product would be entirely suc- be performed in confined surroundings. wearexample. Messrs. J. W. Beresford & Co.,cessful. 80 NEWNES PRACTICAL MECHANICS November, 1940 ANOTHER NEW GRAYSON TOOL S. TYZACK & SON LTD., TOOL & MACHINERY SPECIALISTS TwistThe "Zyto"Drill Grinder, adjus- table for drills win. tofin.; quick and acc- Superior qual- urate indispens- able where drills tionGrinding areused15/6 Polishingand Complete ine. "011ite'" bronze bearines. Larger size, Self centric Win. to lin. drill AUTOMATIC DIE -HEAD jaw chuck. 43 Takes both hi" & I" Standard Dies.I", 1" or I" Shanks. Capacity 0-f Centre ,15/6 complete POST /3 FREE DELIVERY FROM STOCK " ZYTO " Super Quality Sliding Tallstock Dieholder. E. GRAY & SON, LTD., No.1 M.T. Shank Long 18-20, Clerkenwell Rd., London E.C.1 Barrel, Precision Fin- (LE 1174 EST 1822 ish.For it in. 0.11. Dies. Price 8s. 3d. MOTOR VEHICLES For lin. 0.D Dies, 10s. IN A Please send us your NUTSHELL enquiries. By Major S. Bramley-Moore, M.C. Describes in simple, clear-cut language the construction and working of a modern motor vehicle. Inhis official capacity the author has taught thousands of men to drive and to know what goes on when the wheels go round! 154 pages.Nearly 50 diagrams and illustrations.Bound in limp cloth.Fits the pocket. " ZYTO " The Contents Include: SIX HOLE AUTOMATIC TURRET TOOLHOLDER. The Chassis Laid Bare Automatic locking,Correct alignment assured.Tools not in use Construction of the Engine swing well clear of job in hand. No 1. M.T. Shank. 42s.Tools extra. 2/ NET The Cooling System CATALOGUE OF ENGINEERS TOOLS INCLUDING LATHES AND Lubrication of the Engine GEO. ADAMS SPECIALITIES ONE SHILLING POST FREE Of allbooksellers orbypost2/4 from The Electric Circuit at Work Object of the Gear Box C. ArthurPearsonLtd.,(Book Dept.), The Steering Gear, etc., etc. Tower House, Southampton Street, 200 Practical Questions and S.TYZACK &SONLTD. 341-3450IdSt1 LONDONE.c.' London, W.C.2. Answers GALPINSTECHNICALLY QUALIFIEDWindproof-Rainproof-Stormproof ELECTRICAL STORES'ENGINEERS 75 EE HIGH ROAD, LEWISHAM TILLEY LANTERN Key Men of the War Tilley Lantern burns ordinary paraffin. LONDON, S.E.I3 Qualify by home -study with The T.i.G.B. for Big Pay Equally useful for indoor or outdoor Telephone: LEE GREEN 5240 Technical Posts in Wartime Engineering-Aeronautical, work.Oilcapacity 11pints,giving Terms: Cash with Order. Mechanical, Electrical, Chemical, Wireless, etc. 10 burning hours.Absolutely safe. ELECTRIC LIGHT CHECK METERS, small, late Do not be disappointedifyou cannot type, well-known makers, in good condition, electrically Howto Qualify :- guaranteed for 200/250 volts 50 cy. 1 phase A.C. mains; Takeo recognised Engineering Qualificatior obtain prompt delivery ofthese famous 5 -amp. type,61-:10 amp.,7/6:20 amp., 9/- each. Post 11 - TilleyLamps. Remember that, owing on all types. such as A.M.I.Mech.E., A.M.I.E.E., A.F.R. totheirexcellence, they arein great A SPECIAL LINE ---MAINS TRANSFORMER for Ae.S., A.M.I.Chem.E., etc.,in which pro- demand by the three fighting Services Dug -out, lighting off 12 -volt car bulbs, input of Trans- fessionalexaminationsT.I.G.B.Students whose requirements must come first. former is 260/240 volts, output is 12 volts at 8 amps havegained 25 FIRST PLACESand Price 7/6 each, 6d. post. Hundreds of Passes. Steel for the manufacture of Vapourisers TEN LINE CORDLESS TELEPHONE PORTABLE is difficult to obtain.Owners of Tilley EXCHANGE BOARD, complete with nailing gener- Write to -day for "The Engineer's Guide to Success," Lamps are earnestly requested to hand ator in new condition, £613.01-.Carriage forward. containing world's old Vapourisers when pur- PORTABLE VOLTMETER IN OAK CASE, 7 x 6 x widestchoiceofen- in their 4 in. First grade moving coil. 0 to 12 volts.1016, post 1/-;gineering courses cover- chasing new ones from their Iron- ditto, size 5 x 4 x 2i in., 7/6 each, post 9d. ingallBranchesand monger. EXR.A.F. MORSE KEYS, massive silver contacts.qualifications. Sold byall good Ironmongers well-balanced movement, 7/6, post 9d. andStores. Catalogue from :- EVER READY TORCH CASES, 5 x4x 31,high grade, complete with switch and handle, oak case, brand TILLEY LAMP CO., HENDON, N.W.4 new, 2/6 each, post 6d. 300 c.p. MANGIN LENSES, convex, 41 in. dia., new, 7/6 each.The Technological EX R.A.F. WALL FITTING LAMP, brass case. glass dome, complete with 12 -volt 15 -watt bulb. 3'6 ea, Institute of post 6d.: ditto, wing type, complete, 3/6 each, post 6d. EX R.A.F. PORTHOLE AEROPLANE LAMP. 6 in.Great Britain dia., complete for red, white, or green light, solid metal construction, complete with 12/14 -volt 50 -watt bulb218 Temple Bar House (new), 6/6 each, post 6d. London - - E.C.4 OSRAM 100 -VOLT 15- bVATT PEARL LASH'S. Sd. each, or 7/- Per dozen. VOLTAGE -CHANGING TRANSFORMERS (Auto GAIN HEIGHT NOW Wound), 100/110 to 200/240 volts or vice versa. Guaranteed 12 months. 250 watts, 25/-; 500 watts.32/6:1,000 watts. WHEN REPLYING TO 50/-; 1,500 watts,62/6. Delivery 7 days from date of order TheChallonerWay D.C. MOTOR BLOWERS, 2 in. inlet and outlet. ADVERTISERS Many have already obtained those Aluminium body, laminated field,ideal for dug -out vital extra inches with the aid of ventilation.100 volt,25/-. PLEASE MENTION CRYPTO SHUNT WOUND DYNAMO, 12/18 volts, 8110 Challoner's Famous Formula amps, 2,200 r.p.m., in new condition, 37/6, carr. forward. PRACTICAL MECHANICS HIGH -VOLTAGE TRANSFORMERS, useful for all H. T. N. TABLETS test work or television. Input 200/240 volts, output 5,000 and easy system; well tried and safe. and 7,000 volts, 6/6 each. post 11-. Nostrenuousexercisesorold-fashioned MAINS TRANSFORMERS, 200'250 volts input, 12 and 24 volts at 4/6 amps. output, suitable for model trains, appliances.Ifone box is insufficient etc., 15/- each, post 1/-. HAVE YOU A RED NOSE? we guarantee to supply a further box EX R.A.F. AUTOMATIC CHARGING CUTOUTS FREE.G. Y. (Watford) writes: "t AND VOLTAGE REGULATORS, for 12 to 20 volt up Send a stamp to pay postage, and you w:II have never had confidence in any sys- to 20 amp. circuit (new) and complete in metal case. learn, free of charge, how to rid yourself of tem till I tried yours, now rye gained 3/6 each, post 9d. EX R.A.F. GLASS ACCUMULATOR TANKS, 5 x 5 such a terrible affliction. inheight, weight and fitness."Act x 8 in., new and unused, 3/6 each. Post 1/, Address in confidence- now!Full particulars lid. (part post- EX R.A.F. SWITCH PANEL, with case (new), fitted age).Sample 9d.Book on height improvement 3d., 6 small knife switches, leads, cords and cleats, complete P. TEMPLE, Specialist stamps or P.O. only.Sent under plain sealed cover. in wood case,2/6each, post 6d. 32 "Commerce House," 72 Oxford Street, W.1 Dept. C88, EX R.A.F. AEROPLANE DYNAMOS. for accumu- THE CHALLONER CO., lator charging, 12 volt 8 amp., 1.750 r.p.m.. 10/- each. (Est. 39 years.) Laboratory and Works, Hyde Heath, Amersham, Bucks. Carriage 2/6. November, 1940 THE CYCLIST 43

AU letters should be addressed to the Editor," THECYCLIST,"George Newnes, Ltd., Tower House, Southamp- ton Street, Strand, London, W.C.2. 1 'PhoneTemple Bat 4363 \ - relearams: Newnes, Rand, London Editor :F.J. CAMM in the world. He was the coloured cyclist VOL. IX NOVEMBER. 1940 No. 225who held the world's championship in 1899 and the American championship in 1900. The other books areBicycling as a Comments of the Month Hobby," which is written by R. C. Geist, President of the College Cycle Club, and By F. J. C. "Bicycle Built for Two," by James and Elizabeth Young. The Purchase Tax 12 committee members. It appeared obvious from the start of the meeting that theThe Kenora Race THE purchase tax came into operation oncommittee intended to have its decision October 21, and of courseitincludesupheld and although the committee must 148 -mile cycle race held annually bicycles and certain accessories. A quainthave felt unhappy about its decision,itTHEin Canada was won this year by a 41 -year - position, however, has arisen. Dealers willwas enabled, by reason of its 11 votes, plusold veteran, Julien Sansen.The previous not be permitted, it seems at the momentthose of the few supporters of the committeewinner was Higgins, who this year finished of going to press, to include the purchasewho turned up, to have the decision ratified.second, whilst Maurice Pothier was third. tax on stock in hand prior to October 21.It is only right that delegates who did not Sansen's time was 6h. 49m.; Higgins, Therefore, readers may expect to find in aattend the meeting should know that theiih. 49m. 30s.; and Pothier, 6h. 51m. given district some machines and accessorieschairman refused to disclose the name of the being sold at the old price and some at theproposer and seconder of the resolutionSummerTime new, for not all dealers carried heavy stocksalthough there were aspects of the matter on October 21. Those associated with thewhich the chairman, in his capacity as an AT the moment of writing it has not been Hire Purchase Trade Association, however,impartial guardian of the rights of all, decided to allow summer time to con- state that it seems fairly certain that theshould have allowed to be aired.It has,tinue throughout the year.Although this retailer will be allowed to average the priceshowever, emerged thatthecommittee,step has already been taken in Germany, of his goods within the Prices of Goods Act,unable to find a valid reason to supportthe conditions over here are not precisely asbetweenthosepurchasedafterthetheir decision, had to revert to quibblessimilar. The arguments, however, in favour Purchase Tax came into operation, andwhich they raised after the appointmentof allowing summer timetocontinue those in stock before. It must, moreover, behad been declined.We know from dis-through the winter months outweigh the remembered that the trader is not allowedcussions that some members of the com-disadvantages. to make a profit on the Purchase Tax. Munition workers will particularly appre- mittee and many delegates view the matterciate it, especially now that usual forms of The Position of the Hirer with concern. It is observed that the pro-transport are not always available and the poser and seconder of the resolution (theirfoggy weather will add to the delays. There IT also seems clear that where goods arenames are known to us), sheltering behindis little point in munition workers working destroyed or damaged by war, the hirerthe protectionconveniently affordedbytwo or three hours overtime each evening is not liable for the repair of the goods orthe chairman, had not thecourage toif that time is to be lost by late arrival in theirreplacementiftheyarelostorspeakinsupportoftheirresolution.the morning due to traffic delays.It is in destroyed, nor is he liable to continue toR.R.A. delegateswillagreethatitissuch circumstances that the bicycle demon- pay for them. Moreover, he is not liableextraordinaryprocedure(andthis isstrates its handiness.Itis the door-to- for damages or compensation for the loss ordescribingitincharitable terms)for adoor travel link between home and work, damage to the goods. committee whose decision is challenged, to give as its reason, a statement which wasas well as the vehicle to transport the owner The New W.R.R.A. - 50 " Record calculated to mislead, and which containedfrom war worry to the delights of the matters which could not have formed part ofcountry lanes when leisureisavailable. CONGRATULATIONStoMrs.Anntheir original deliberations. The special gene-Bicycles will not be so plentiful during the Briercliffe on the remarkable time sheral meeting, therefore, ratified a decision ofwar, for the materials from which they are made in her successful attack on Mar-the committee on evidence which had no partmade are more urgently needed for war guerite Wilson's 50 -mile record. As reportedin their original decision, and moreover, uponpurposes.Dealers' stocks are running low, elsewhere, she returned a time of 1h. 59m.evidence that had no relationtotime-and there is not too much time, therefore, 14s.,thusbeatingMargueriteWilson'skeeping, and for which satisfactory explana-to select a machine if you want to be time of 2h. 7m. 59s. It will be remembered,tionsweregiven,supported bylettersindependentoftraffic.problems. The that Mrs. Briercliffe held this record for afrom the Auto Cycle Union, Professor A. M.Purchase Tax will increase prices, and we few hours in July at 2h. 9m. 29s.This isLow, and J. Burden Barnes, O.B.E., andtherefore advise all readers who do not at the first time that a woman has beatenvariousspeakerswhotestifiedtothepresent possess a bicycle to obtain one now. 2 hours for a "50." There does not seemappellant's ability. See that it is properly equipped with good immediatepossibilitythat Marguerite The voting (by secret ballot, a show ofbrakes, a good headlamp, a good touring Wilson will return to the attack, althoughhands on a decision being refused) was notbag, and carry a repair outfit, spanners, it is our view that under the same conditionsunanimous -10 in favour, 20 against. Ofand spare bulbs if electric lighting is fitted. on the same course as that used by Mrs.these latter,11 were committeemen. andSelect a machine to fit you; the range from Briercliffe,shewouldhavebeenevenseveral timekeepers. which you may make your choice is not so faster.The new recordis one of which wide as it was in peace -time, but it is im- any male time trialist would be proud. portant that you should have a machine America Goes Cycling upon which you can ridecomfortably. Extraordinary R.R.A. Procedure Spend a little time adjusting the saddle IN America there isa great revivalof height, the reach and height of the handle- WHEN the spacious days of periodicals interest in cycling, no doubt as a resultbars, and the fore and aft position of the return, we shall have an interestingof theincreaseinimportsofBritish story to tell of the extraordinary proceduremachines which make the American imita-saddle. adopted by the R.R.A. at a special generaltion motor -cycle type look ridiculous.TheClub Socials meeting called by the Editor of this journal.Americans are now learning the difference He called upon the committee to showbetween pushing a weighty dreadnoughtM OST clubs have changed the venue of reason why he was not re -appointed as anand pedalling a lithe and livelyBritish their annual dinners, and many have R.R.A. timekeeper for1940.Instead ofmachine of low weight.Further evidenceabandoned the idea of a dinner and are giving the reasons, the chairman read aof this interest exists in the fact that tworunning a Sunday lunch instead.There statement which dealt with points which were new books on cycling have recently appearedwill not be so many annual prize-givings, not raised until after the committee's decisionin America, and there is a re -issue of thefor prize -winners have been asked to select (which was not unanimous).was questioned.well-known autobiography of Major Taylor,their prizes and to take possession of them Only 18 delegates turned up in addition to the who claims to be the fastest bicycle rideras soon after the event as possible. 44 THE CYCLIST November, 1940 Road Sport NOTES OF A THOSE clubs which carried on road sport ' during the past few months have every reason to be satisfied with their efforts. Scores HIGHWAYMAN of events were held and there were no incidents to bring down official criticism of the sport. By L. ELLIS Women's Road Records A Market Woman's Philanthropy INTEREST in the Women's Road Records IT is not often that a memorial is of so extensive a shows no signs of abatement. Cycle and nature that its position occupies a considerable tricycle records have been beaten and further area on the map. Maud Heath's Causeway, however, improvements in the near future are suggested. will be found on most maps of the Chippenham No attempts have been made this year on district.The lady is said to have been a market R.R.A. records, although the machinery forwoman of Langley Burrell who died in 1474.The checking any claim is waiting to be put instory goes that she had had a hard life and had motion. great sympathy with those who, like herself, were compelled to trudge through swampy country to Dispatch Riders Wanted take their market produce to Chippenham. She thereforeleft money and property not only to MANY battalions of the Horne Guard stiltprovide, but to maintain for ever, a footway from " require cyclist dispatch riders and signal-Wick Hill to Chippenham Cliff, a distance of about lers. Among these is the Altrincharn Battalion four miles.Her wishes have been carried out, and whose headquarters are at the DrillHall, to -day the Causeway stands in excellent condition Hale, Cheshire. and serves as a footpath alongside the more modern road. A monument to Maud Heath's memory stands Irish Record on a hill at Wick overlooking the Wiltshire plain. ANEW 100 -mile Irish tandem competition A statue, showing her with staff and basket, crowns record has been set up by. T. F. Quinn andthe pillar, and the inscription, which is not remark- E Kirwan (City of Dublin Club) with a timeable for its good spelling, reads: " Erected at the of 3.50.40. This is nearly three minutes faster joint expence by Henry, Marquis of Lansdowne, than the corresponding British record. Lord of the Manor, and Wm. L. Bowles, Vicar of the Parishof Brimhill,trustees1838." Where the causeway begins on Wick Hill there is a stone with An Unpleasant Experience the inscription : "From this Wick Hill begins the R.C.J. COLE, well-known membeioithe praise of Maud Heath's gift to these highways." " North Road Cycling Club, had recentlythe At Kella ways there is a pillar with a sundial. and unpleasant experience of his house being gutted by an incendiary bomb. To add to his discomfiture he was, at the time, out with other A.R.P. wardens putting out a series of small fires caused by incendiary bombs in nearby woods. The fire in his home burned Cycle "Tax" tor two hours before being noticed. )111,RIDGWATER tradersrecently suggested that 'a the N.C.U. should advocate that cyclists taxed themselves by contributing half a crown to "Spit- He Won a Dagger fire" funds I 'Bridgwater traders should concentrate WINNER of the "Major Liles" Trophy as theon trade in their own area. Best All Round Tricyclist in 1939 and winner of the Tricycle Association Championship in the same N. C. U. Move year, Gordon E. Thomas, now with the Honourable Artillery Company "somewhere in England," won THE N.C.U. has taken up temporary accommoda- a one -mile and a ten -mile massed start cycle race tion away from the heart of London and is now confined to members of H.M. Forces.For eachcentred at 35 Baltic)] Avenue, Highams Park. Lon- event the first prize was a dagger' don, E.4. Cycling Luncheon Tricyclists, Please Note tricyclists. whether members 01 the M EMBERS of Southgate Cycling Club willmeet" ALLTricycle racing Association or otherwise, having per- in the Salisbury Hotel, Barnet,on Sunday, formances to their credit at 50 and 100 miles and November 10, for an informal lunch and re -union 12 -hours in Open of T.A. events, should send particu- which will be a substitute for their 48th annuallars of these to G. E. Lawrie, 132 Henley Avenue, dinner. Ilford, Essex, so that the winner of the "Major Liles" Memorial trophy (for the Best All Round A Remarkable Summer Tricyclist) can be adjudged. IT is now permissible to give some account oithe summer's remarkable record.If you wonder why Broken Glass worn tyres stood up so well remember this-it was the driest August since 1818, the hottest June for 44 WITH so much broken glass about in many streets, years, and the century's worst drought was rivalled I stouter tyres seem advisable.Yet the average It was the warmest May for 18 years and the brightest tyre seems to stand up well: when did you last since 1929.July provided eight or nine degrees ofpuncture? We've heard of atleast one cyclist MaudHeath's Causeway, near Chippenham frost on the nights of the 13th and 27th. For dearth puncturing on a shell splinter ! of rain the past summer has not been matched for 19 another inscribed stone is to be found at the Chippen- ears I "Cycle -Widow" ham end of the path.At the foot of Wick Hill the path Is carried over a stretch of marshy ground by MUCH has been written, and spoken, about themeans of a succession of small stone arches. about Released from the Army golf -widow,"butlittleaboutthe "cycle - widow." But because her husband went cycling on sixty in number. LA OLDER of the Land's End tee John o' Groats Sundays without her, a Glasgow wife deflated the " unpaced R.R.A. tricycle record (3 days 19 hrs.tyres of her husband's machine I Words followed and A F igh2va :man's Retreat 56 mins, in 1929), Leslie J. Meyers his been releasedthere was a sequel when the wife summoned her ICR .itIN'S fame, or should it be notoriety, from the Army to resume his work of Nationalhusband for assault in a Glasgow court. The Millie V isgenerally associated with London and the importance as a key -man in an aircraft works. (a former Clarion rider) advised the pair to make it York Road, and it comes like something of a shock to up and said :"Cycling is the cleanest thing a man be reminded of his sinister figure in the placid beauty Scrap Metal can do.I wish more men would go out riding on of Corve Dale.There, sure enough, at a_place called Sundays." locallyAston Munslow, although the map says SCRAP metal is needed for use in the manufacture Munslow Aston, is a delightful little inn claiming of armaments, yet nobody in authority has yet a one-time connection with the robber.I suppose, seriously suggested that the millions of steel studs Immobilising Cycles like everyone else, I am apt to subscribe to a halo scattered all over the country in streets and roads THERE isno regulation demanding that cyclesfor Turpin Robin Hood and the other picturesque should be collected for scrap. must be immobilised, yet in some areas the policebrigands.Whether I agree with their methods or not. are acting in a high-handed manner and cases haveas one Highwayman to another I certainly admire been reported when cyclists' machines have been Turpin's choice of inns.This little place lies in the Bicycle Boom tampered with and the tyres deflated. A war reserveheart of one of the peaceful valleys of Shropshire, BICYCLES are " booming" and even in military constable, in the North London area, was found bya wide valley reminiscent of the Scottish straths or circles their utility is recognised, many cyclingthe owner tampering with the valves of his machine. Wensley Dale.The road runs roughly north-east units being now formed. The cyclist asked the policeman what he was doing to south-west and is flanked on the northern side by and the officer answered that he was "teaching thethe parallel ridge of Wenlock Edge. On the south, owner a lesson." The cyclist asked under what section more distant and more broken, are the slopes of the Still Rides an Ordinary of the Act the constable acted and added that unlessBrown Clee and the Titterstone Clee.The dale MR. TOMMY" CHARLETON, president of thesome reasonable statement was made he would extends approximately from Ludlow to Much Wen - Wellam Cycling Club and the well-known North report the matter to a higher authority. Despite his lock and is charming throughout its length.Dick of England rider, still finds great delight in riding anblustering the constable was cornered and at theTurpin is said to have arrived in Corve Dale early Ordinary. He recently put in a day's ride of 43invitation of the wheelman pumped up both tyresone morning in a brewer's dray and the story goes miles. "Tommy" is a past -president of the annualto the amusement of a crowd which had gathered! that he called at the Swan Inn at Munslow Aston. Barnard Castle meet. It is a quaint old place dating back to the fourteenth century, and is in an excellent state of preservation; Black -out in fact itis rapidly becoming modernised.Twin Sir Alfred Robinson I_OOK to your lamps-especially your front lamp black and white gables adorn the roof, and eight stone SIR ALFRED ROBINSON, K.B.E., C.B., deputy after black -out. The top half of the glass should steps lead from the road to the bar parlour.Until secretary to the Ministry of Transport, who is be blacked out and the lower part of the reflector quite recently there was an immense chimney up interested in the cyclist's cause, recently retired. rendered Ineffective. Many police prosecutions have which the sweep's boy used to crawl.I was too late He has attended several dinners of the Road Records been made regarding ineffective lights of late and, in to see this old relic, as on my last visit I found a Association. one court, a fine of £2 in each case inflicted. brand new fireplace of new and ugly design. November, 1940 THE CYCLIST 45

Whenyou get a Firestone you really are getting the best tyre for your money-thanks to the skill

OLDFIELD and experience of British Tyre SPORTS This deep rugged lyre is renowned for its Engineers whoarespending The Firestone Sports tyre is designed for substantial saving in first cost, yet giving speed with extra safety.Its light weight is achieved by extra fine quality - ensuring wonderfulmileageandsafety. Sizes their life designing and produc- flexibility and liveliness and great strength. 28xt,26xr1,28xt.26x11. Sizes 26 x 26 x 1;, red or black. Tube 1/10.Cover 4/5 ingtheworld'sfinesttyres. Tube 2/4.Cover 6/1 Look into these specifications and prices-they're extraordinary road value as many cyclists have proved.

SPORTS TANDEM With a deep tread of Sports tyre design and High quality at a wonderfully low price, cord fabric impregnated with extra rubber only made possible by the experience and the Firestone26 xr4Tandemtyrehas skillof Firestone Tyre engineers. Sizes extrastrengthandlivelinessperfectly 28x z6 x 11,blackonly.26 x balanced. 26 x red or black. Tube 2/7.Cover 6/I Tube Cover 1 6

ROADSTER The deep rugged tread of the Firestone Road- ster gives greater safety and mileage.Under- neath are cords of the finest quality, giving extra strength and flexibility.Sizes 28 x 26 x 26 x 1. Tube 2.7.Cover7/2

C.3 FIRESTONE TYRE & RUBBER CO., LTD., GREAT WEST ' D., BRENTFORD, MIDDX. 46 THE CYCLIST November, 1940 marketing a bicycle so fitted-not, I think, during the war, but rather as a part of his post-war programme. The New Minister of Transport Y sincere congratulations to Lt. -Colonel J. T. C. MMoore-Brabazon, M.P., on his appointment as Minister of Transport.I have known him for very' many years.I first met him when he was training to take his pilot's certificate of which he holds the first issued by the Royal Aero Club.I also know him as a keen motorist, and one who has been interested in road problems and transport all his life. There is no one in this country better able to fill the post, and I am certain that he will fulfil his duties with conspicuous ability and with benefit to the State and to all road users. He understands the cyclists' point of view, and will not allow motoring interests to outweigh his judgment.I am certain also that he will undo some of the messes created by Burgin and Belisha. Keith was not in the job sufficiently long to demonstrate his ability.I hope Moore-Brabazon re- mains Minister of Transport until all the multifarious road problems have been solved.It is not generally known that lie is a keen model railway enthusiast, and owns a very complete model railway system, which I understand the editor will shortly describe elsewhere in this journal. Beating the Hour

ISEE that W. J. Robinson returned 59 m. 58 s. for I a "25." The event was promoted by the Herts C.C. and he is thus the fourth to beat the hour in Ireland. It was five years ago that Donegan created the 59 m. 5 s. record for the " 25." Fleming, of course, got well inside. this figure and although there was no doubt whatever concerning his time, he had not given the required notice to the officials, and so the A scene in Brighstone village street-a reminder of past touring holidays in the Isle of Wight record was not officially recognised. In this country Dougherty holds the "25" record with 59 ns. 29 s. whilst Fleming returned 59 m. 38 a. and Nightingale AROUND THE WHEELWORLD-By Icarus 59 ns. 37 s. to the enamelling of cycle frames which Igladly The N.C.U. Spitfire Fund 1941 Road Sport pass on. very fair, IAM informed by the secretary of the Road Time The present professional or commercial method of THE abovefund has nowreached I Trials Council that the National Committee is toenamelling cycle frames is by dipping the frames or proportions and we understand a further £100 meet, probably in London7at the end of the year or pouring the enamel on to them, over a surface which (approximately) has been subscribed.The Union in January, to discuss plans and prospects for thehas previously been made rustproof by one of the has also received five Gold Championship Medals, one 1941 road season. As I see it, the prospects of road many processes now in use. dated 1896, 1906, 1908, 1909 and 1912, from a well- sport for 1941 do not seem too rosy. The services are The enamel is afterwards allOwed to drain off for known Catford member, Mr. W. Taylor. 4111r. Taylor, calling up time trialists in greater numbers. How-a matter of 15 to 30 minutes according to the con-with customary generosity, has asked the Union to ever, there are other matters which the Nationalditions, and stowed at various times and tempera- sell these gold medals for the benefit of the N.C.U. Committee of the R.T.T.C. call discuss, as well astures, according to the conditions in the particular Spitfire Fund. the future of sport during the war. The R.T.T.C. has factory in which the work is being carried out. But although the fund has been going for some been operating now sufficiently long for the experi- The enamel used for the first coating is called anconsiderable time, it is still a long way short of the mental period to be considered as closed. One point undercoating or rubber coat, and the second coat is £5,000 or £6,000 necessary to purchase a Spitfire. which has been raised and which must be discussed is.called the finishing or gloss coat.Here again it is At the present rate of progression it will take over allowed to drain for a similar time and afterwards put 18 months to collect the money. whether Press men should be allowed to serve on thethrough the oven as in the case of the undercoating. committees. Of course, it is readily understood that the amateur could not enamel his frame under these conditions N.C.U. Moves Claude Hulbert's Skit but there are many types of air drying enamels now Tli E N.C.U. has moved to temporary accommoda- on the market by- which he can get very good results. ATTENTION was recently drawn in these columns tion att5 Balliol Avenue, Bighorns Park, London, The process recommended is to thoroughly clean off E.4-telephone number Larkswood 2490. to the remarks made over the air in the course ofthe old enamel and rust, if any, with the aid of emery a talk on bicycles. One of those remarks was that the paper, and afterwards apply a coat of enamel.In bicycle isdifficult to immobilise, and this journal the case of black, one coat is usually sufficient, but Accidents pointed out that it was one of the easiest vehicles to incolours you should give two coats of enamel- immobilise. Claude Hulbert evidently thought so too, Fl TREK confirmationforthearguments for in his radio turn which followed a few nights later, undercoating and finishing. The all important part advanced by this journal against the speed limit he lampooned the remarks of the previous talker in a is, of course, to see that the work is perfectly cleanare to be found in the return of road accidents most amusing way. He said (of course, facetiously)and free from rust orgrit.Furthermore, many issued by the Secretary of the Ministry of Transport that he agreed with the speaker who said the bicycle failuresare due to the amateur buying a goodfor the month of August.If we take accidents to was difficult to immobilise. Even if you removed thequality enamel and yet a poor quality brush, thecyclists alone, we find that 55 were killed in August, front wheel he understood the Germans had been result being the bristles readily come out, which 1939, on roads subject to a speed limit, whereas in training as unicyclists so that they could ride on the for some unknown reason always seem to be full of dirt. August, 1940, this number had increased to 68.In back wheel only. Moreover, he said, should you be August, 1939, there were 64 accidents on roads not ultra -cautious and remove both front and back Improved Power Crank subject to a speed limit, and 61 in August, 1940; thus wheels, he understood that they were being taught to AN ingenious mechanism which is applicable to a for August, 1940, there was a total of 129 cyclists ride on the chain wheel only. bicycle, but is not so well known as it ought to killed, as against 119 in August, 1939.The figures, be, is shown in the sketch.Its object is to utilise however, apart from cyclists, show similar increases, Patents in War Time greater leverage during the working half of the strokeand I am hopeful that Lt. -Col. Moore-Brabazon, with without increasing the length of the crank. In thehis mathematical mind, will be able to perceive the THE warhas naturally stimulated the production application shown, two eccentric sheaves are keyedmistakes of the two Leslies, Belisha and Burgin, and of inventions and the Government departmentsto the driven shaft on each side of a chain wheel. The abolish the speed limit and the pedestrian crossings, have a special organisation for dealing with them cranks are extensions of the eccentric straps, each and the unwarranted liberties which are given to during the war. A note is taken of any patent applica- connected to a lever arm keyed to the shaft by a linkpedestrians, who in my view are far more responsible tion which, from Itstitle,appears as thoughit a. Each crank is hi advance of the arm in the direc-for accidents than any form of vehicle. As a fact, might be of interest to one or other of the Ministries. tion of rotation.This device with ball bearings there were 618 people altogether killed in the roads When this is the case, a formal letter is sent to the between all sliding parts, has been patented and oneduring August, 1939, and no less than 729 in August, applicant, asking him to submit further particularswell-known bicycle manufacturerisinterestedin 1940. and explanation of theinvention.Government departments have, of course, the power to prohibit "Shake" Earnshaw for R.A.F. the publication of the particulars of any invention which might be of benefit to the enemy and they also SHAKE" EA RNS HA W,famousprofessional have the right to take over and to use an invention, cyclist, is likely to don Air Force blue in the or to make the Invention secret; they may even delay near future.lie was recently seen at a North of acceptance of the application for the period of the England depot of the R.A.F. where prospective war to avoid publication.These actions do not flyers and groundnien undergo preliminary question. abrogate the inventor's rights to his invention, for ing prior to being called up within a few weeks. although the Government is entitled to use it for the national benefit, and are not obliged by law to make Keep Your Head -Light On any payment in respect of it, they do in practice make a suitable payment.If they are unable to I ADVISE all cyclists to ignore instructions from agree with the inventor with regard to the amount of I A .R.P. wardens and members of the Home Guard payment this is settled by arbitration. to put out their headlights during an air raid. The A.R.P. and the Home Guard are voluntary organisa- Enamelling a Bicycle tions which have no standing in law so far as lighting isconcerned.The administration of the lighting NOW that it is difficult to purchase new bicycles, laws remain in the hands of the police. A Chief many will be turning their attention to renovat- improvement Constable may instruct his officers to have cycle ing the old ones. lamps extinguished, but a policeman may not order Mr. W. T. Downes, Works Manager of the County Obtaining greater leverage on a crank duringthe you to put yollr headlight out unless he has received Chemical Co., Ltd., has sent me some notes relating working stroke. such instructions. November, 1940 THE CYCLIST 47 la bigbike-. i I r _y FOR CONVENIENCE li On your journey to work, on shopping expeditions, or for visiting your friends 'Go toit 'by bike. It's by far the easiest and most convenient method of getting about and- stsTclic:act YDUR Dunlopsaddle a also patent a LonCYCLE Choose has its waterproof, loses L arid never top saddle Ilex Dunlop Ir` TYRES a Theres DU shape machine. typeof for every Are the most reliable in the world.

40H/326

This is why THE WORLD'S BEST CYCLE BRAKES "CANTILEVERS" (Regd.) " The enclosed cable was fitted in Glasgow in September, 1933, and has been in regular use ever since.Most of Scotland has been covered,including all the roads in Skye and Mull, the whole of the west coast from Stranraer to Tongue, Writefora freecopyof and such' roadsas the' road to the Isles'and the North Strome-Applecross an illustrated booklet. Road. These examples will give you an idea of the test the brake was put to."

"CANTILEVERS " cost 12/-each,front or rear in nickel or enamel finish. Chromium Plated, 14/-. For Tandems, 13/-each, THERESILION 121' front or rear (chrome, I5/-) 200. LIVERPOOL ROAD. LONDONN.I. William The Conqueror was an Expert at Physical Jerks He could(anddid) throw his weight about to some effect, both at Hastings in1066 and elsewhere afterwards. In these days of "enlightened" travel, cyclists all over the world find physical or mechanical "jerks" conspicuous by their absence, since the cycles they ride are equipped with Williams Chainwheels THE CO figiiiier0/3`of EDWARD WILLIAMS TRANSMISSION TROUBLES Foundrx Lane - Birmingham 48 THE CYCLIST November, 1940 WAYSIDE THOUGHTS By F.J. URRY

ofthe knee and ankle joints, and the toggle of power that resides in the muscles controlling them.Mackintoshes It is the use of the natural spring in the human make- THIRTEEN miles every day is my business riding up, and its application to crank revolution is the portion unless the snow is too deep for steering secret of easy riding. Our styles may differ as does ourway, and I have never yet been more than dampened build, but the persuasion of the pedals over the dead on the journey. Good mackintoshes are the answer, centre "points" is one of the things the human cancape and leggings; not the flimsy things sold at a do better than any engine. price, but a cape with plenty of room under it, and leggings that do not fit too tightly.It is waste of Club Riding, money to buy cheap waterproofs, yet the temptation to do so is very great, for most people excuse their FROM my observations the men and lads are the bargaining on the grounds they will so seldom need worst offenders in this matter, for it seems as if the to use them, so the cheap type will do. They expect natural daintiness of the girls kept them from formingto keep them in the bag as a kind of charm against this bad cycling habit. Regular riders know what Iwet weather; but when the moment comes, and the mean, and with use most of them deplore' the fact rain descends as it most surely will, then they know that this descent froth perfection in the riding ofin less than half an hour the saving of pence has only a bicycle is so common. The club cyclist is seldombrought them discomfort. Buy the best macks you can guilty of this error whatever else may be chargedafford, and see that the cape is roomy, does not grip against him, and that is one very good reason why all your shoulders, which means it will surely ride up folk who desire to make cycling a pastime of pleasure your back when in service. Wet weather riding is an shouldgive some adherence-however slight-toart in patience. Most people start to ride harder when club riding.It is the best way to learn easily and it rains, which is absurd, for that means discomfort N mid -September I was lucky enough to obtain a comfbrtably the tips and hints that make riding afor the sake of saving rive minutes. Go more slowly; few days' leave, and as usual spentit riding abicycle far more than the mere acts of balance and just sit comfortably in the saddle, drape the cape over bicycle, and escaping the charge of selfishness by force.I stress this point because so much dependsthe bars at the front, and the bag at the rear, and joining my family at Bala, they having journeyed on correct pedalling; indeed it is the main link that keep as still as you can, except for your legs, ankles thither by car, a very small car used for the purposemakes cycling so delightful a travel method, and and feet.Use your lower gears to travel the slope or of conserving petrol. My ride to Bala was 'a perfect once it is acquired, -and there is no difficulty about bore into the wind, andif the gradientisstiff, journey, just an idle trail of miles through an ever-that-itis likeswimming.you neverforget,it. walk it. changing countryside which became more colourful as I neared the mountains and entered that superb Gate of Wales by way of the Vale of Llangollen. Lonely riding has its advantages inasmuch that you stop where you like and smoke, eat when you feel hungry, and as in this case, with no occasion to hurry, just meander amid the beauty and absorb that type of sanity which is always closely akin to nature. It was just glorious; the sense of freedom, the loveli- ness, the wind and the sun, and the personal power to collate those everyday things to the undiluted enjoyment of the moment. That is cycling in the best sense of the pastime, a conditioned achievement I would not change for any other form of travel.I was riding a six years old machine which had just been fitted with a Sturmey-Archer four -speed medium ratio hub giving ranges of approximately 69, 60, 52, me an added interest in the going.To mai the gear changes were most complementary, and I went the hilliest way to try out the various gears. Had you told me four gears on, a bicycle were desirable a few months ago,I should have found itdifficult to believe, but my recent experiences have made Inc a firm adherent to this new and delightful combination. The changes are so slickly easy-a flickof the finger-that you are encouraged to use just the gear most suitable to the grade or the wind, with the result that your riding is easier, and on the long slopes or the sharpish rises you are not conscious of tremendous effort. The Angel, Bury St. Edmunds Among The Velsh Suffolk. A famous Dickensian Inn dating from1779. DURING this littlereleaseIrodenearlythree It hundred miles among the Welsh hills, with the occupies the site of three older little car frequently trailing me and carrying the inns. The Angel, The Castle picnic outfit; nor did I flinch at the little secondariesIndeed proper pedalling s cycling, for all the rest of that rustle between the mountains and take you intothe game is centred round that nimble action. and The White Beat remote spots, because I had the bicycle and the gear In this connection I think it wise to stress, that combination to make the going without strain, and which should be obvious to the novice but apparently well within my powers. Occasionally I walked a few is not, to walk before the effort of propulsion hurts. hundred yards of the steepest pitches to stretch my There is nothing clever in riding a hill for the sake of legs and look around at ease with the world, but for pride ; in fact it is unwise, for strained muscles are not Druvno Rain Dia most part I could sit up and spin that 43 to the a pleasant trouble, and the aches that result some- HAVE ridden all day n.driving rainwithout summit of the passes, slowly and enjoyably. times prohibit sleep. How do I know? Well, I was getting wet through. The edges of my coat have I had been lunching with the family about a mile once young and thought I could race without proper been dampened, and so have the ends of my sleeves, on the Dolgelley side of Barmouth Bridge on a high training, and naturally paid the penalty. while a change of stockings (which I always carry in plateau of ground completely hidden from the road, the bag) has been grateful and comforting, because and had just started to amble back to Bala with the Change of Exercise heavy rain on a long journey trickles down the wind behind and the perfect vision of the Mawddach leggings and percolates the lace holes of your shoes. Valley in front of me, when a couple of riders passedTHERE is really no great need to do much walking, When I have to face driven rain for a fair period of me, making for Barmouth. We exchanged the usual even inahillycountry,if one'smachineis time I usually tie a light handkerchief round my neck greetings, but as these cyclists passed my unseen moderately geared; butIfrequently tramp the to preserve what dignity my collar may command, people on the bank, they overheard this conversation, length of a hill just for a change of exercise and theand I always roll up my shirt sleeves to keep them That was old Frank Urry; what a pity we did notexcuse for a smoke. Hills that are easy to ride in the free of the drift of moisture thrown up by the front stop and talk to him, he might have mentioned us in summer or when the wind is favourable, often prove wheel when coasting down hill. his notes."Such is the small reflection of fame; quite tough in other circumstances, so because you That is all there is to it, but the greatest of these but 1 object to the qualifying adjective to my name, once rode a grade fairly comfortably, it is no reason things is to ride easily and then you will ride enjoy- for though I have become a trifle bleached on top, why you should always be able to do so. And fitness ably.Personally, I can and do enjoy a rainy ride, I refuse to consider sixty-one summers as signifyingcounts tremendously in this matter.If you havethe airisusually so clean and the roads so very a state of decay. been out of the saddle for some time, you will findmuch your own. Besides it seldom rains all day in lack of practice has its handicap, and most certainly this country, and those immediate hours after the you won't get fit again by the process of strainingcessation present the wanderer with some ofthe " Middle -Footing It" on the leash as it were. The golden rule for pleasureloveliest visions in pastel shades of softness possible wowEvER, I do not want to bore you with mycycling is to take it easily always, and then in due to imagine. " small adventures, and only recite them inthe time you will begin to realise the latent power of the 1 remember some years ago persuading a friend of hope they may encourage a few folk to ride a bicyclehuman body to adapt itself to this " mechanical mine, who hated wet riding, to join me on a journey more for the joy of wandering, than for the healthinesswalking" and enjoyably cover anything up to a to Peterborough, an eighty milestrip, and though of the game or its undoubted convenience. There is hundred miles in a day, if you want to, without he was dubious at the start of that ride, he frankly such a lot to learn about cycling as I see the matter feeling unduly fatigued. admitted at its ending he had never enjoyed a day's by observance of the multitudes who use a bicycle- I ride to business every day of the working week cycling more. And it rained all that day, and far into wrongly I think in so many cases. because I like cycling, the fresher air of the highway the night until every lazy stream had become a torrent Take for instance the people who trundle along the as opposed to train or bus or car, and the individual and the Soke of Peterboros' seemed well named. road "middle -footing it." They look stodgy and they freedom from time tables or the price of petrol. The pleasure of that ride was based solely on our easy are stodgy, moving the wheels by the application of"But," say my unconverted friends, "What aboutjourneying, which averaged rather less than eight sheer brute force instead of that nimble pressure pfthe bad weather; what about when it rains and miles an hour,including meal times, and finally power that comes of correct pedalling.What isblows, the nights are dark, and the black -out looksbrought us to Peterborough with only a change of correct pedalling? It is the full use °We flexibility awesome ?' stockings necessary for our comfort. November, 1940 THE CYCLIST 49 look round there was nothing to see but heaps of f a rubble and piles of scrap metal. itler Hac BeenCyclis Rectfying Frontiers Hitler has talked much and often about frontiers, By Reginald C.Shaw and rectifyingthem, and liberatingpeople and making unhappy folk rejoice, but the truth is he IAA sure that Hitlerii (Mid have been a much knows nothing about such things., When he's been happier man if somebody had given him a bicycle cornered and confined-as he will le-the people of and taught him to ride it. Germany must be shown what a fool he was, and I have been everywhere that Hitler litabeen.In what fools they themselves were, because at present fact, I got there first-and I did it with much less they think he is the only wise man in Europe. fuss. Somebody will have to buy them all bicycles and Take Czechoslovakia, for instance. When I crossed take them touring.They've never done that in the frontier from Austria I had with me a mere hand- erniany yet.(Jr course they do snake same use of ful of mounted men-C.T.C. members. We rode up bicycles, but they don't use them for pleasure.,Nor to the frontier guards quite openly and produced would you, if your machine was a German model. twenty-five bits of paper (one for each of us), given to Great clumsy things they are, with two-inch tyres and us by the Foreign Travel Department of the C.T.C. prehistoric brakes. They a're out of date, like German Not a shot was fired.People were glad to see us: ideas of neighbourliness. they wanted to give us presents, to shoW us' this and When this war is over there will be,1 hope, a that, and to make sure that we were really happy. stream of British cyCles flowing to the Continent, We were. followed by a stream of British tourists to show the Hitler, on the other hand, had quite alot of people what to do with them, Then they may learn difficulty in getting into the country.He talked sense. They may learn that the way to live at peace about it for months before actually trying it.And with your neighbour is to pay hint a friendly call now then he needed More than twenty-five men on and again, on a bicycle, and without your temmy- bicycles.He had to have hundreds of tanks.An guns and screaming bombs.They may see in the awful expense, and a tremendous amount of trouble. end that frontiers are only front doors, and that they will be opened for you if you knock on them instead In Poland of trying to knock them down. lt, was the same in Poland.When my platoon swooped down on the frontier post in the Carpathians Staying At Home we met no opposition whatever. In fact the customs Staying at home is not good for anybody.Those officials asked us to step into their office and make who never pay calls on their neighbours are the ones ourselves comfortable until the rain stopped. We who cause the trouble-like Hitler.He had never couldn't stay as long as that, but we did hang around been outside his own country until he started rainp- for an hour or two. aging about Europe with his clockwork soldiers. Later on, it is true, an old lady shouted out to us That's the trouble with most Germans : they think as we rode towards Cracow :" Are you going to start there is no need for them to go anywhere; they think another war?" but she didn't bother to take cover. they know all there is to know about the rest of the although I bet she did when Hitler and his gang world without the trouble of looking at it. came swaggering into the district. We must take them in hand when the present spot When I visited Warsaw there was something to see. of bother is over. We must take them by the hand and It was a beautifid city, a placeIshall never forget. Poznan Memorial to theRestored Poland -- lead them gently over the countries they have smash- But when the Bavarian boor turned up to have a one of the first things Hitler destroyed. ed up, and make them realist' what fools they've been.

safe place-and I notieed that it weighed just about double one of Illy bicycles !-I observed that the My Point of View tyres were as flabby as they could be, providing the rider with the peak of discomfort.I refrained from making any remark, because for one reason. you can't By "WAYFARER" teach parsons anything. and, anyway, Isis tyres were in such condition that they might, have rebelled at His back wheel was ditoneti i.rom the rest of hisfurther presssite. But what "gets me" is the habit of bicycle, and the tyre was dismantled. At the momentsome people in using tyres which are not in really of our encounter, he was endeavouring to inflate the reliablecondition. Even at enhanced war -time tube with the bellows God gave hint, expecting thus prices, tyres are cheap enough, in all conscience, and. to achieve sufficient distension to enable the puncture in my view,itis an excellent investment so to to be located. What a hopeless dawn ! "shoe" your wheels that you purchase immunity from trouble. That way lies confidence in your bicycle and enjoyment in your pastime, And it may also prose Asking- For It to be the cheaper policy, as a man 1 met recently is Nipump-always a good one-made short work now convinced. '' of the inflation job, and them as the leak refused to show itself, 1 took the tube and set off in search of water, which was discovered in a horse -trough at Devoid of Wisdom a farm half a mile awayIn less than no time I was THJS merchant had a bit of bother with one of his back again, anditdid not take long to make a ' tyres, and took it to a shop to be mended.The repair, assemble the tyre, and replace the wheel.I repairer, a wise old owl, whose word .can be relied allowed my friend to carry out the inflation actupon, pointed out that the tyre had seen its best because a cursory examination of the cover revealed slays, and that a repair would not be a good invest- that it possessed two or three "sore places," and Iment. The customer knew better, or he was "econom- preferred not to have the responsibility of bursting theising," and declined to launch out into the expense of tyre through what, in the circumstances, might bea new tyre. The very next day he was in trouble over -inflation.That was rightly his "funeral," not again. The tyre gave way as lie was cycling to his mine.Then, having a spot of good advice lyingwork. He lost half a day's pay through being late- I 113E! handy. I gave him some with regard to the folly ofand he then had to face the expense of new "fur- IEll II riding forth without a pump, and the further follyniture" for his wheel. A distorted idea of "economy.' of using a tyre which was manifestly worn out. On to ply mind ! the first point, it may be remarked that there is more than one way of carrying a pump :on the second point, I always feel that cyclists who take a chanceFour -Wheel Cabs Galore with tyres are crying aloud for trouble. And, often enough, they get what they demand ! My friend saw t -NN one of my recent evening jauntsintothe glowing countryside, Icame across afield the wisdom of my remarks, and I then went -on mywhich was veritably littered with four-wheel cabs way, delighted to have been able to render a slightof the horse-drawn class, the purpoSe being, of course. service to a brother of the wheel-and thankful thatto prevent enemy aeroplane landings.It was a my schedule, such as it was, could afford a break ofcurious sight, and one could not help wondering about 30 minutes. where this collection of old-fashioned vehicles had been reposing since the motor ear came along and Pump It Hard pushed them off the road.I, personally, -have some- cyclist THIS may be a good point at which tosay athing of a reputation as a hoarder, but-believe it The Foolish ' word or two on the subject of tyre inflation. Howor not-I have never gone in for hoarding four-wheel WAS pedalling my way very serenely along timemany of us fail to pump hard enough !One might cabs ! Thames Valley a few days ago when I discerned a. have to make allowances when using the boulder - brother cyclist who was grappling with the minorstrewn streets of, say, industrial Lancashire, but, in nuisance caused by an unauthorised perforation in general terms, we should pump board -hard, thus gain- one of his tyres. As one good cyclist should always ing in personal comfort and prolonging the life of our A NEW BOOK say to another, in such circumstances, I called out : tyres.To my way of thinking, a flabby tyreis "Are you all right?"-and the reply proved that hedistinctly uncomfortable, and it is always a joy to was in anything but that desirable and happy con- harden it.I find it a good plan, during the inflation dition.He answered my question with another :process, to pump the tyre as hard as you think it GEARS AND " Have you a pump? iHad I a low, indeed? shotild be, and then test it, pressing the two thumbs, Would. I venture to cross the road without one? So,close together, firmly into the thread of the tyre -- GEAR CUTTING with time to burn, a halt was called, and I set aboutremembering, the while, that the tyre has to carry assisting a fellow cyclist in slight distress. He proved your10, 12, or 14 stones. Then, having decided that By F. J. CAMM to be a school -teacher, who was regularly doing atheis just right, push some more air into the 20 -mile ride each Gay to get to and from his job.tyre, and that will be that ! A few evenings ago I 5,- or 516 by post Owing to the fact that one of the brazed -on pegs hadencountered a perfect example of how not to use from George Newnes Ltd., Tower House, Southampton broken off, he was not carrying a pump, and thus, tyres. A parson came to my holm to supper, and Street, Strand, W.C.2. with a puncture, he was well and truly "in the cart.' he travelled by bicycle. As I. -put his machine in a 50 THE CYCLIST November, 1940 Sportfolio Classified Advertisements RATES -Twelve words 2t. (minimum). 2d. per word after.Each paragraph charged separately. Racing News of the Month NEW CYCLES HOBBS OF BARBICAN, manufacturers of modern frames, cycles, tandems and tricycles. Special- Irish Polo ists in frame design.Lists and individual quota- THENorthern Ireland Bicycle PoloAssociation tions free.Personal attention to every order. -34, ' recently held their annual general meeting to elect Barbican, London, E.C.1. officers for the forthcoming year.The following wereGroseSpur All British Cycles,75s.Art List 100 elected :I. Carton, chairman; I. Paddington, vice-models free. -Grose, Ludgate Circus, London. chairman; W. I. Mullan, hon. secretary; W. Nelson, treasurer; A. Smith, press secretary;S. Harkness BAINES Super Responsive Cycles.Ultra short and T. Thompson, referees' representatives. W/Base,orstandarddesignmodels. New The winners of the Northern Ireland Summer catalogue free. --Idle Road, Bradford, Yorks. LeagueweretheRangers,with the Wrens as runners-up. ACCESSORIES i-IEORGEGROSE, the best house for all cycle accessories.Write for beautiful art illustrated Ann Brierclifte's "SO" Record list, post free, 3d. -Ludgate Circus, London. NN BRI ERCLIFFE, Glasgow amateur, brought ^ the British women's 50 -mile record inside two CLOTHING wTATERPROOF your coat(leatherorcloth), Ann Briercliffe, West of Scotland Clarion, who broke hours on October 6th, when she clocked lh. 59m. 14s. for the distance.This is eight minutes forty-five gloves, shoes and saddle without stiffening the British W.R.R.A.50miles record on October 6th. seconds better than the previous best, which wasthem by brushing on Granger's Solution Grade 1212, is the first below two hours colourless or coloured.1/- bottles, 1/9, 3/- tins from Her time of lh.59m. 14s. recorded by Marguerite Wilson, the Claud Butler Camping Outfitters, Stores and Halfords. to be recorded by a woman. and Stormy -Archer professional, in July. Mrs. Briercliffc- used an East of Scotland course INSURANCE Scott Still Winning for her successful attempt.Good conditions pre- ASK your dealer for one of our Insurance Certifi- vailed, and she finished fit and undistressed.She cates; or write direct Vehicle and General In- WILLSCOTT,the popularScottish crack used a variable gear, and Mr. G. R. Herd, officialsurance Co., Ltd., Royal Liver Buildings, Liverpool, recently added one ntore "25" to his longlist timekeeper of the Women's Road Records Associa- of successes, this being the Lancia "25" in which he tion, followed throughout the ride by car. TYRES clocked lh.1711.41s. Some very fast times were She also broke her previous Scottish "50" record returned in this race, and Scott only just managed toas well as the Scottish "25," "15" and "10" records, NEW TYRES. Clearance, best makes, "pip" J. Armour of Auehterdon Wheelers, who waspreviously held by Eleanor Collins, of Edinburgh. 10,00033k% off standard prices.Carriage 16s. behind the Crawiek rider.It is interesting toThe improvements in the three latter records were paid. Price List on application. -Davies, Tyre note that Mrs. Ann Briereliffe rode in this race and also substantial, and the new times are 53m. 30s., Factory, Wednesbury. returned a time of lh. 14m. 50s. 31m. 56s., and 20m. lls.All the new figures are subjecttoconfirmation -bythe, Women's Road Fast 25 Milers Records Association andtheScottish Women's MOST of theMidlands'fastest25 -milers were Cycling Association. THE CYCLOMETER included in the 75 entries for the East Midland Clarion "25" which was run off recently.The race MANUFACTURERS was won by P. E. Possart, Solihull, who clocked New Hill Climb Records 1 h. 4m. 44s. FFIRST and second men in the classic Hamilton C.C. Standard Model - 2/11 each hill climb beat the previous fastest time for the Be Luxe Model - 3'6each Glasgow Finals hill. T. 111'Nulty,GlasgowWheelers,clocked To Fit 24", 26" or 28" Wheels. THEfinal of the Scottish Track Cyclists' Association 1m. 2/55., and J. B. Jamieson, Bonawe C. & A.C., CAtamillal half -milenovicechampionship,heldatthe Ise .53 4/5s. Jamieson held the previous record ofH. J. Thormann Engineering Co. Ltd. Plate I Westhorn track, Glasgow, was won by G. Edwards of lm. 59s. put up last year. The hill has a gradient PERREN STREET,LONDON, N.W.5. BRITISH the Nightingale C.C. of-in-7 and a length of 600 yards. MADE

\\\\,/ z",.-. , 1. &elsboa Protr\Ong ° - Retax" ;Int -_,./--e,_____:_-,-_, --1 It's a wise cyclist who YOu r_liSteries hashis brakes fitted with Fibrax Brake Blocks. They never fail TRE VITA BATTERY SAVER BULBS to grip in any situation MAKE EACH BATTERY YOU USE LAST AS LONG AS TEN -a sudden stop, a slow Ref. 124.2.5v. withI Ll mm. Ball Balloon and M.E.S. Cap for use either down in dense traffic, a for Head or for Rear, or for Torches ...... 71d. safeguard on a hill -it's Ref. G247.3.5v. with III mm. Ball Balloon and M.E.S. Cap for use either for Head or for Rear, or for Torches .. .. all the same to Fibrax. Economical, too, they WHEN A BRIGHTER LIGHT IS REQUIRED willfaroutlastany TRE VITA ECONOMY BULBS ordinary block. What- MAKE EACH BATTERY YOU USE LAST AS LONG AS FIVE ever your make of machine, there's a Fibrax Brake Block Ref. G246.2.5v. with III mm. Ball Balloon and M.E.S. Cap for use either tofitit.Ask your dealer. for Head or for Rear, or for Torches' ...... 71d. Ref. G248.3.5v. with 11', min. Ball Balloon and M.E.S. Cap for use either -for Head or for Rear, or for Torches ...... VA. WHEN REALLY BRILLIANT LIGHT IS REQUIRED TRE VITA BRIGHT LIGHT BULBS WILL GIVE YOU THE BRIGHTEST LIGHT PROCURABLE Ref. G245.l.5v. with III mm. Ball Balloon and M.E.S. Cap for use either for Head or for Rear, or for Torches ...... 7Sd. BRAKE Ref. 6257.1.5v. with 11I mm. Ball Balloon and M.E.S. Cap for use either for Head or for Rear, or for Torches ...... 7.1d. Ref. G258.3.5v. with 111 mm. Ball Balloon and M.E.S. Cap for use either BLOCKS' for Head or for Rear, or for Ton hes .. LINERS

- For REAR LAMPS use Ref. G125. L5v. with 11 ! mm. Ball Balloon and M.E.S. Cap.. .. 7.' d. WITH CYCLE DYNAMOS-TRE VITA" TUBA "GIVE LIGHT AT WALKING SPEED. Send for Price List.Individual bulbs supplied.No charge for postage Vitality Bulbs Ltd., Neville Place, Wood Green, London, N.22. FIBRAX LTD., 2, Tudor Street, London, E.C.4 4. BUY, EXCHANGEOR SELL Advertisements are accepted ior these columns at 3d. per word (minimum 12 words at3s.-advertisements of less than 12 words are charged at the minimum rate of 3s.) subject to a discount of for 6 consecutive monthly insertions or 5% for 12 consecutive monthly insertions. TERMS :-Cash with order.Cheques, Postal Orders, etc., should be made payable to George Newnss, Ltd.The Proprietors reserve the right to refuse or withdraw advertisements at their discretion.All advertisements must be received on or before the 5th of the month preceding date of publication and should be addressed to the Advertisement Manager," PracticalMechanics," George Newnes Ltd., Tower House, Southampton Street, Strand, W.C.2.

LITERATURE MUSICAL INSTRUMENTS MISCELLANEOUS BAND GUIDE.Hints on the Bugle, Drum, Flute, TELESCOPES, MICROSCOPES, Scienti tic 160 PAGES ILLUSTRATED REVISED WORK- StaffParadeformation,etc. Free,postpaid.- instruments, etc.Send for lists.Sale or Exchange.- SHOP HINTS and Calculations in Calvert's Mechanics' Potter's (Manufacturers), West Street, London, W.C.2. C. V. Bolton. F.S.M.C., 49a Leigh.Road, Leigh, Lanes Handbook, 8d.,postfree.-Sherratt & Hughes, St. Ann Press, Park Road, Timperlev. Ches. CASTING MOULDS.-For Lead Soldiers, Indians. Animals, etc. Sample mould, 3/-.Catalogue stamp.- STAMPS Industries 2, Waldegrave Park, Twickenham.

qtiol FREE I! Twenty Unused Colonials." Neurope, Ilse 1 Fifty for 1/1}:_d.-G. H. Barnett, Limington, PHOTOGRAPHY Somerset. PHOTOGRAPHIC MATERIALS. Plates, films, mounts, chemicals.Interestingmoney -savinglists s7 TOOLS free.-" 'timber's," 105 Queens Road, Brighton. a,Kol GRAYSON.'S CdaAs-boring Outfits andTube. WATCHMAKING 50,00 Cutters-avoicErisk.--Velow. "Easily the Best Soldering DRILLS, Taps, Dies, Files, Chisels anch.Pupphes. WATCH & CLOCK REPAIRERS. Send dd. for Fluid Obtainable." This Best quality at keenes6.prices.-Grayson & Cothpatty, complete list of material and tools.-Blakiston & Co., statement by a regular user 300 Campo Lane, Sheffield. .Hinsdale, Southport. of "BAKER'S" expresses the opt a' general opinion of the Motor .10/11,NO NEW POWER TOOLS ofquality. aSily made from our and Engineering Trides. IOa'bandgtis, 54s.;..ligsavis,2es.tido Bench castings Drills,lls.;circulag Saws frcum25s.;3 -inch S.C. Soldin6d., V- and 1/6 tins. From also in bulk. Toolroorn LatheS, ffitlIp.£4 5s. New 1 -inch chromium - plated Mmrometets, 12s. 6d.; Electric Drills, 37s. 6d., 12/6 Per Set SIR W. BURNETT & Co. (CHEMICALS) LIMITED Grinders.-John P. Steel, Bingley. .HALLAM & SON GREAT WEST ROAD. iSltWalta,..M11)°1.1°StR. Machine Von, It" Jaws, 1" Deep, opens 31"; complete Upton, Poole, sets of parts, only require drilling and tapping, Dorset. 3/9 set.Burke. M- A ETHOL . . Aeroplanes and Speed 13 it. 1. to 60 xfore. WORM DRIVE 400 Genuine Carborundum Wheels, 11" Wide, 1" Hole, Send 4ff. for par' c tars. . 5" Diam., 1/9; 51" to 6", 2/6; 61" to r, 3/6. Burke. JUBILEEHOSE CLIPS 2,000 Small High-speed Twist Drills, .020" to .065', 2; - The long -life clip with per doz.Burke. I'LL TEACH YOU the ever -tight grip 3 -any Lot.SEVEN LOTS £1 TO PLAY THE PIANO The Best Known Dos. Ass. Whit. & B.A. Taps, to 1" Diam. R.H. Without Drudgery, Fatigue or Failure Even if you are of middle age and do For Radiator Joints, 20 Ass. Ditto, Left-hand, to Diem. not know a note.I can quickly make you play so that you will be welcome Air, Oil, and Water Sq. Toolholder with Four H.S. Tools. everywhere. Sun -clear,fascinating iessons, using ordinary musical nota- Hose Joints Eight Assorted H.S. Tools tor Above. tion, no freakish methods. BY POST, in your home. making failure Impossible. We guarantee a Tight .6" to ilf" Silver Steel, 13 pieces, 13" long, Precision - and enabling you to read and play at sight any standard musical composition.I have Joint ground to size. enrolled more than 1,900 adult pupil.. during the War, have taught over 51.000 Stocked by allGarages a" to I" Silver Steel, 4 lbs., 2" to 4" Long. during 36 years, and I CAN TEACH YOU. and Accessory Dealers Send for free booklet, "Mlnd, Muscle and 1" toll" Silver Steel, II lbs., 11" to 3" Long. L. ROBINSON & CO Keyboard," and form for free advice. Say if Precision -ground, Advanced, Moderate, Elementary. or 25, London Chambers, " 1017,E" Super High-speed Steel, Beginner. nAss., 2" to '3" Long. MR. H. BECKER GILLINGHAM, KENT (British by Birth and 500 Ass. Brass and Steel -plated Screws, etc.; B.A. & Descent) (Dept. 158). Fine'Threads, 4g" to 69.FleetStreet. 100 Bright Hex. Bolts with Nuts, i" to 1" Diam., 1" to 3" 1. E.C.4 Long.SurpriShne Value. 12 Ass. Fine Thread Taps, }" to I" Diem. Trice The 'ADEPT' Bench Hand Shaper £3.10-0 thgif strpke of ram, 31 ins.; Length of FOVLES Three Doe. Tungsten Hack -saw Blades any size,Si"; LltAltVil:of slide, 3 Ins.; Size of Table, 10"; 12". BOOKSELLERS TO THE WORLD tiz4VrHe' eleifseo Ps:Or% zaea,tilrise.: New and secondhand books on all technical subjects 1" Diam.,suitablefor MatinatnoUlestance between tool and table, 18 Grinding Wheels.I"to ins.; IPHIght, 15 lbs. Also the 'Adept' 113-125 CHARING CROSS RD., LONDON, W.C.2 Flexible Shaft use. No. 58.14. Shaper, Cildn.struke. Telephone: Gerrard 5660 (16 lines) £7-4-0. Three H.S. Tap or Reamer Fluting Cutters, it" Dlam , Manufactured by -I" Hole. Woith 6,- each. Machine F. W. PORTASS Vice12 3 SELLERS STREET, SHEFFIELD. 15 ass. Files,4" to Ii".Handy variety. 12 ass. Toolmakers' Needle Files.Indispensable. 12 ass. Carborundum and Fine Emery Wheels, I" to CHEMISTRY EXPERIMENTS f" Thick, 2" to 4" Dim.. all 1" Hole. IN YOUR OWN LABORATORY 3lbs.Best Blue Twill Emery Cloth Strips, I" to 2" Wide; ass. Superfine to Coarse. Post Free OFFER of SAMPLE PARCEL £1 orders Carr. Paid except abroad. containing many usefulpieces of J.BURKE, 41, SUNNYVALE ROAD, SHEFFIELD CHEMICAL APPARATUS OUR ADVICE BUREAU Increasing numbers of Myford 3A" and 4" Lathes are being used on Aircraft work, COUPON 2/9 because of their adaptability. Write for This coupon is available until Nov. 30th., 1940, Write also for and must be attached to allletters containing FREE PRICE LIST illustrated list to -day. queries, together with 3 penny stamps. A stamped of other Sets. addressed envelope must also he enclosed. (Scientific Dept. A), 60, High SI. MYFORD ENGINEERING Co Lid PRACTICAL MECHANICS, NOV., 1940. Stoke Newington, London, N.16. [Weston, ilottinqham,b5oee A fen JI961 Booklet. "Experiments in Chemistry," 6d. P.O. All applications respecting Adve,tising in this Publication should be addressed to the ADVERTISEMEN" \ AGER, GEORGE \l.1\ Ts ES L'I'D., Tower House, Southampton Street, Strand, London, W.C.2. Telephone :'emple liar 4353 Send for copies of Gamages Tool Bargain Leaflets GUARANTEES THE VALUE for Metalworkers GAMAGES and Woodworkers High -Speed ELECTRIC HAND -DRILLS A high-grade tool with exceptionally fast penetrative power.Takes up to1/4 -in. drill. Gamages' priceissubstantially lower than that asked for similar drills elsewhere. Complete with good length of flex. For 200/240 volts A.C. or D.C. Please state voltage when ordering.

BOXES OF TWELVE ASSORTED FILES The best and cheapest way to buy Files. British made and ex- This Super cellent quality. Sizes 6 to 12 in. WORKBENCH 12 for 516 DOUBLESIDED Post 9d. TO -day'sValue Also sizes 4 to 8 in., 12 for 3/3. Below Post 7d. At Pounds rigid. Fitted with strongand very side), 2 in. Exceptionally (one either Super Quality Record " 7-in. vices Smooth, cleanfinish. ELECTRIC SOLDERING IRONS two English beechtop. bench stops, British niade.Length, 12 in. Fitted thick solid Fitted two with a 6 -oz. copper bit, loading 80 Extra heavydeal underparts. erul).All parts excep- watts. Complete with 2 yards of tool racks(one at each Bolt heads are power flex, two large together. and adaptor. and bolted missed. Splendid GUARANTEED tionally heavy not to be SIX MONTHS pelleted. A bargain value. sunk and 4 ft. 6 in. long Post 7d. £101 2 ft. 6 in. high .6 9 1To-day's Value 2 ft. 3 in. wide£6 I7 Heavy Duty, Block Type Borden Tube Type outside our freedelivery area Carriage forward CONDENSERS MFD capacity.PRESSURE GAUGES Suitable for volt-Calibrated to 10 lb. per square POWERFUL 12VOLT A.C./D.C. ages up to 1,000inch, but can be calibrated to A.C. or 2,000 D.C.approxi- GEARED MINIATURE MOTORS Testedto4,000mately at a very keen price volts D.C. Dimen-double ? sions approxi-this pres- A.C. MOTORS (cy5c.es) Commutator type. sure. Overall measure- mately 4% in. wide KAU &DKRER Will work through any 9in. overall height,Amazing VALVE TESTER suitable transformer. ments (excluding fin.thick,bakelite.value. Rating, 12 to 14 volts shaft) 2% by 2% by case. To be continuous, to 2% in. Weight 2 lb. two minutes at cleared at 23 volts. Shunt wound, but an enormous Post Incorporat- reduction. 7d 2. ing bi-metalthermal can easily be altered cutoutand auto- toseries, matic clutchto avoidthen machine operates on 30-40 breakage undersad-volts. Post 7d. SET OF POCKET SOCKET SPANNERS den stoppage. Re- For ignition and household use.Smallest and most comprehen- versing switch.self- INSULATED PLIERS sive eight -piece seton market.Comprises seven sockets and lubricating bearings. Ro- , , 1, and tor speed(noload)Tested to 12,000 Made in C.S.A. handle. Sizes %, 2000,r.p.m. Output volts -ar hexagon, jin. round knurled, spindle speed 38 r.p.m.Insulated with and 1/4 in. square. All brand new and remark-thickrubber,in Complete in steel ab e value. two sizes, rack. Length, 4f" Illustration is approx. one- 6 in.2t. Post 7d. third actual size.Post 7d. 7!6 7 in., 2/6. Post 3d, Britain's Biggest Value inTool Chests 61SHEFFIELDIE MADE TOOLS 1 INCHEST FOR 97'6 Contains an exceptionally comprehensive range of fine quality tools-suitable for practically all woodworking Jobs.Chest stained and polished walnut colour.Size: 27 in. by 11 in. by 7/in.Fitted with fixed compartments for small articles, and movable tray with 24 spring clips to hold chisels, bits, etc. Contents :1 Skew -back Handsaw, 22 in.; 1 Tenon Saw. I! in.; I Set 3 -blade Compass Saws; 1 Pad Saw and Handle; 1 Smoothing Plane, 2 in. double iron; 1 Joiner's Hammer, No. 2; 1 Claw Hammer, No. 1; Joiner's Mallet, 5 in.; All -steel Hatchet, No. 1; 1 Cased Oilstone, 8 in.; 1 Joiner's Square, 6 in.; 1 Sliding Bevel: I Spirit Level, 6 in.; 1 Spokeshave, 21 in.; 1 Marking Gauge; 1 Cabinet Turnscrew, each 4 in., 6 in.; 1 pair Pincers, 6 in.; 1 Handled Chisel, each I in., 1 in., f in., 1 in.; Handled Gouge, f in.; 1 Joiner's Plain Brace, 9 in.; 1 Centre Bit, each f in., f in., f in.; 1 Special Auger Bit, each fin., % in., if in., 1 in., f in.; 1 Boxwood Rule, 2 ft.; a pair Combination Pliers; 1 Putty Knife; 1 Paint Scraper; 1 Mitre Block, 9 in.; 2 Gimlets; 2 Bradawls; I Glue Pot; 1 Cold Chisel, 6 in. by in.; 1 Tack Hammer ;16 -in. Half -round File and Handle; 1 4 -in. Saw File and Handle; 1 Centre Punch; 1 Nail Punch: 1 Packet of 12 Sheffield Twist Drills; 1 Pencil. Carriage (outside our free delivery area)3,- extra. England 8, Wales

GAMAGES, HOLBORN, LONDON, E.C.1 Telephone. HOLborn 8484 Published about the 30th of each month by GEORGE NEWNES, LIMITED, Tower House, Southampton Street, Strand, London, W.C.2, andPrinted in England by THE SUN ENGRAVING CO., LTD., London and Watford, Herts. Sole Agents for Australia and New Zealand-Gordon & Gotch, Ltd.Sole Agents for South Africa-Central News Agency, Ltd.Subscription Rates :Inland and Abroad, 9s. 6d. per annum.Canada, 9s. per annum.Registered at the G.P.O. for transmission by Canadian Magazine Post.