THE AUTOCAR a Journal publtsbet') in tbe interests of tbe mecbantcall\? propellet') roab carriage.

EDITED BY H. WALTER STANEq,

No. 7r9. VoL. XXIII.] SATTJRDAY, JuLY 3rsT, rgog.

[PRICE 3D.

The Autocar.

(Published Weekly).

Registered as a Newspaper for transmission in the United Kingdom.

Entered as second-class matter in the New York (N.Y.) Post Office.

Three Editions every Friday,

The THREEPENNY EDITION, printed on Art paper. The PENNY EDITION, printed upon thinner paper. The FOREIGN EDITION, price 3d., printed on thin paper for transmission abroad.

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CONTENTS. NOTES USEFUL HINTS AND TIPS (ILLUSTRATED) .• THE ASTON HILL•CLIMB {ILLUSTRATED) LONG DISTANCE COMPETITION IN SWEDEN ON THE R OAD THE R.A.C. \IVARWICKSHIRE MEETING (ILLUSTRATED) ON THE TRACK . . 8ROOKLANDS AUGUST M EET!NG PROGRAMME R OAD VlARNINGS .. THE PERSECUTION OF MOTORISTS JN \VALES

PAGE.

. . 155-156

157 . . 158-159

r 5g 160- 161 162-164 . . 165-1 66

166 . . 167-172

Boov DEliIGN AND CoNSTRUCTtON (lttUSTRATED)-A FouR NOTE

173

GABRIEL H ORN (I LLU5TRATED)-FRONT \,VHEEL BRAKES MOTOR UNION NOTES • • SMALL C AK TALK .. SOME PRACTICAL ACCUMULATORS AND ACCUMULATOR BOXES

174 1 75 176

( lLLUSTRATED)-PALMER CORD TYRE STUDS (ILLUSTRATED) -SUMMERS' \VtND SCREEN (lLLUSTRATt:D) THE VIEO VVHEEL (lLLUSTRATED)-A SECURITY BOLT IMPROVE-

MENT ([LLUSTRATED) . , THE R.A.C. HEADLIGHT TRIALS (ILLUSTRATED) • . CORRESPONDENCE (lLL UO::TRATED) FLASHES • • C LUB D OINGS

177

178 179-180 185-190 19 1- 192 193- 194

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Abroad (thin paper edition), 22s. Sd. per annum. Index to Advertisements appears on page 40.

Notes. Practical Tyre Improvements. From descriptions and reports which we have published recently, it 1,ill be seen that some really practical advances are being made in the matter of rendering pneumatic tyres still more reliable. The pneumatic tyre of to-day, as compared with the tyre of only three or four years ago, not to mention any earlier date, is extraordinarily reliable, especia lly when new. We use the 11·ord new advised!~·. and do not merely mean that a tyre is reliable for a week or two, but rather that it is very unlikely to go wrong till it has passed through about threequarters of its active life. From this period and distance it may burst at any time. We do not mean that it will blow a hole in itself six inches Ion!!, hut rather that some old puncture which has gradual ly brought about a loca l weakness in the cover will suddenly en large so that the air tube 1rill fail and bloll' quite a small hole through the cover. This sort of th ing is now being stopped by the reinforced air tube - in other words. a tube which is not entirely dependent upon the support of the cover. but which has some strength of its own.

We believe there is a great deal more in this principle than is at present appreciated, that its virtues are not wholly re·1·ealed by the recent successful officia l trials 1rhich have been made, and that the advantages are even greater than would appear at first sight. Strengthened air tubes should unquestionably result in longer life to the covers, because they can be used fo r much longer distances without fea r of bursts, so that a vast number of t)Te stops should be abolished. On the other hand, the strengthening of the air tube. although it renders bursts very unlikely. does not make puncturing impossible. and a coYer, whether old or new, is always subject to this risk, and it is therefore interesting to note that. simultaneously with the successful attempts to improve the air tube as such, success is also being attained in the direction of protecting it from outside attack by making the col'er more nearly invulnerabl e. while the old idea of interposing an a rmour betll'een the cover and the air tube is also showing promise. This is, as it were, a middle course. It takes it for granted that the nonpuncturable cover can scarcely be made, and that therefore something which is practic'ally invulneraule should be interposed between the c01·er and the air tube.

Recent Advances. Although it is true that an ab olutely non-puncturable and, at the same time, practical pneumatic tyre has not yet been produced, it is 11·ell to bear in mind that great advances ha 1·e been made, anrl th at every advance spells longer life, as if the tread ne1·er cuts and ca rcely e1·er punctures it means that its real strength i unimpaired. The main . cause of serious tyre trouule is failure of the ca nvas, ~a used by cutting and rotting. Only the deep cuts damage the canvas at once, but clamp penetrates the holes in the tread of the tyre and sets up rotting of the canvas 1ralls encn 11·hen the cut is not deep enough to damage the canrn3 at the moment of the cut occurring. As the strength of the cover depends enti rely on the strength of the fabric, it will be seen that, useful as an unpuncturable am:.our between cover and air tube may be because it . protects the air tube, it will not alone conduce to the longevity of the cover. That can only be ensured by protecting it by a tread which is as nearly unpun ·turable and uncuttable as mav be. If the canvas cannot be cut, it will never rot, is there will be no holes on the treacl through which water can penetrate to the canvas.

It is not our practice to mention specific articles when dealing with general principles in these notes. ~ evertheless, it is . ometimes desirable to do o to make our meaning clear. As an illustration of a combination which should _give something very near to the present possible maximum of reliability, w~ may suggest a