Page:Motors and motor-driving (1902).djvu/268

236 Also keep oil away from the tyres, or it will rot them.

Do not be afraid to pump the tyres hard, especially if carrying a full load. They should never splay more than half an inch.

Never let the car rest on deflated tyres.

In the case of wire wheels, make sure that the spoke-heads are properly covered by the tape.

Test spare tubes by inflation in water, for possible minute leakages.

Do not, however, construe air-bubbles from the valve as a sign of permanent leakage. The needle of the Michelin valve does not fit absolutely tight under the light inflation of an unprotected tube, but under full inflation in the cover may be air-proof. A good plan when tube-testing is to stop this slight leakage by moistening the needle in the mouth.

Keep all spare tubes completely deflated and away from the light. Brown paper is a good preservative. Do not wrap up two tubes together, or the pins may cause punctures.

Always carry at least two spare tubes when driving, and more if the wheels are unequal in size. Spare covers should also be carried when those in use are much worn.

Never start a journey without a pump, a lifting jack, and a fully furnished repair box. See, also, that the pump nozzle has not become detached from its socket.

At every stopping-place it is worth while to examine the covers, in case nails or flints have become embedded in the tread.

When a nail cannot be found, in case of puncture, the cover should be carefully examined for possible flints or pins.

Be sure that the wheels are strictly parallel to each other. To determine whether a tyre is fully inflated, stand on the step and oscillate the car; the expansion of the tyre at its lowest point should be inconsiderable.

The Michelin 'cradle,' or metal nail-catcher, is a useful device to attach to the back wheels, as it may strike off nails