detect the fact of a puncture at once in a back tyre, when the road is itself bumpy. In a four-seated car the rear passengers should glance occasionally at the driving-wheel tyres out of consideration for the driver, and if either of them be splayed at the point of contact with the road he should be apprised of the fact at once.
If he decide, upon dismounting, that the tyre is punctured, and not merely short of inflation, the car should be jacked up so as to permit free movement of the wheel. The tyre should then be cleaned, the best article for the purpose being a brush with wire bristles; the type is known as a 'jeweller's scratchbrush.' Loose dirt should also be wiped from the spokes. If these precautions be neglected every movement of the wheel
_0262.jpg)
Fig. 2
will cause particles of dirt to fall into the hollow of the cover, whence they must be removed at all costs. If a cloth be damped with water or petrol the dirt will cling to it readily, and can be quickly wiped away.
To Remove the Tube.—To remove the airchamber tor examination the valve cap should be unscrewed and inverted, the pin being then pressed into the valve stem so as to push away the needle (see fig. 2). Deflation may be expedited by loosening the large nut and pulling out the plug, especial care being taken not to lose the little needle with its shell-shaped head. Then unscrew the winged nuts almost as
