0EOt:MtiER 7TH , 1907.

THE AUTOCAR B :Journal publis bet > in tbe interests of tbe mecbanicalll? propelleb roab carriage.

EDITED BY H. WALTER STANER.

No. 633. VoL. XIX. SATURDAY, DECEMBER 7TH, 1907. [PRICE 3D.

THE AUTOCAR.

(Published Weekly.)

Registered as a n~wspaper for t r ansmission in the United Kingdom,

Entered as second-class matter in the Hew '!c,rk (N .Y.) Post Office.

EDITORIAL OFFICE :

COVENTRY.

PUBLISHING OFFICES :

20, TUDOR STREET, LONDON, E.C., ENGLAND.

CONTENTS.

PAGR

NOTES • • • • • • • • .. .. .. .. • • 927-928 US E FUL HINTS AND TIPS (ILLUSTRATED): To R E MOVE A STuo-To

PREVENT DAMAGE TO Rnt OR TYRE-A M EANS OF PREVENTING GREASE DROPPINGS-THE FAN IN COLD WEATHER . . • • 929 TH E NEW 35 H .P. TALBOT CAR (ILLUSTR ATED) , , . . • • 930-931 HINTS AND TIPS FOR AUTOMOBlLISTS-THE ATTENDANCE AT OLYMPIA 93I IN QUEST OF A CAR (CoNCLl!DED) , , 932-933 THE VALVELESS CAR (ILLUSTRATED) 934-935 THE NOAKES LUBRICATOR (ILLUSTRATED).. • • 93 :i NoTEs ON BRAKES. Bv E . T. HUMPHRIES 936-937 THE 22 H.P. S .C .A.T. CAR (ILLUSTRATED).. 938-939 G AS ANALYSIS A ND CARBURATJON • • 940-943 THE FIRST CAR THROUGH SoMALTLAND • • 944 CORRESPONDENCE • • . . • . 945-950 ON THE ROAD. Bv OwEN JOHN • • • • • • 951 A STUDY IN WIND SCREENS (ILLUSTRATED) 952-953 REVJEW . . . . . . • . . • . . . . 95 4 A SOUTH AFRICAN GYMKHANA ( ILLUSTRATED) • , • • • • • • 955 To PRESERVE CAPE C ART Hooos {ILLUSTRATED)-MORE JOURNAL·

ISTJC METHODS

FLASHES , , • , , , , ,

THE BENT ALL (ARBURETTER..

• • 955

956-958

. . 959

AEROPLANE DEVELOPMENTS • . • • . .

A N EW ARMSTRONG-WHITWORTH ENGINE..

. • 960

. • 961

SoME QUERIES AN D R E PLIES, . • • • • • •

• • 962

THE R EPAIR OP (RACKED CYLINDERS ( ILLUSTRATED) . .

963

THE ROLLS-ROYCE FOOT BRAKE (ILLUSTRATED).. • • • . , , 963 A Two- J ET CARBURETTER ( I LLUSTRATED) -MORE RECORDS AT BROO K• .- LANDS • • • • • • • . • • • , , . 964 hJIRUBBER·COVERED SHACKLES (ILLUSTRATED) • . 964

l'THE AUTOCAR " SUBSCRIPTION RATES: British I sles, 161. Abroad (thin paper edition). 2Jo . Sd . per annam.

otes. amage to the A great deal has been said lately about the damage which is alleged to be done to the roads by the use of studded tyres. P er onally we consider th e proof is lacking tha t studded tyres damage roads seriously. Even allowing for the extra speed, a studded tyre is far less damaging to a road than the metal tyres of a cart and the metal shoes of a horse . Peoole seem to forget that the horse obtains his grip o; the roads entirely by his metal shoes, but they thin k it is very wrong indeed that a motor ca r should obtain its j.!rip through metal studs. In a ny case, it stands to commonsense that whatever damage the studs may do, the horse and t he narrow metal tyres of th e average horse ca rt do in fi nitely more. As a matter of fact, it is not the studs themselves which hurt the roads . We l.ielieve it is the combination of studs and slip, and that if spring checks were unive rsally used there would be very few compl aints about the damage which studded tyres do to the road. It is only necessary to look at the tracks of tyres upon an ordinary soft road and it will be seen that the studded tyre makes no greater impression on the road than the plain tyre, though we have no doubt that when the studded tyre is slipping it does more damage than the plain , but road makers may at least be consoled by the fact that if this be so it is also true that the studded tyre is grinding its studs away and destroying itself at about double the rate a plain tyre would under similar circumstances .

It should be remembered that there are two forms of non -skids which do not damage the roads. One of these is the Parsons chain. To begin with, the chains are not used on a dry day, as th ey are so easily put on and taken off, and in the second place th ey must be fitted loosely on the tyre so that the tyre can creep in the chain. In other words, the effect of the Parsons chains is the same as though the studs of a studded tyre allowed the tyre to g_ain on them. That is to say, the tearing action of the studs on the road is obviated . This point is not generally app reciated . The car does not drive th e chains; it drives the tyre on the road, ,.th e effect of the chains being to all intents and purposes as though they were laid down for th e tyre to run over, and the anchorage given to the road is necessarily very different from that of the metal studs, as in the case of the studs the drive is passing to the road through the studs. Not only so, there is the safeguard in the P arsons chains th at th ey must be fitted loose ly on the tyre, as if they are not so fitted th ey q ui ckly destroy the tyre. The othe r non-skid is the Eyre, which is a lso a lways out of action when th e roads are dry . It will be remembered th at this consists of loops which proj ect beyond the tyre of the wheel, and only come into action when the car moves laterally. They never damage the road except at the moment of side-slip, and then th e damage is infinitesimal. The theoretical obj ection to th em is that they do not come into action till the side-slip has actuall y sta rted, and when they do act it must be rather suddenly. That is to say, th ey allow a side-slio to start and th en arrest it after it bas developel to some extent. Whether this is a serious objectfon or not in actual practice we do not know . In any case, th ese two non-skids at least do not damage the roads, and whatever may be the opinion about studded tyres it is only fair th at the fact should b borne in mind that non -skids exist which have practically no more effect upon the road th an a plain tyre .

We have mentioned the matter at some length , in view of the fact that the auth orities are giving seriour; attention to the studded tyre question , and whil e we think they a re entirely mistaken in th eir belief that th e st udded ty re does serious damage to th e roads, we also think they should differentiate between th e fix ed studs and the more or less fl exibl e chains or loops.