Page:Motors and motor-driving (1902).djvu/272

240 1901 by the Falconnet Perodeaud Co., of Choisy-le-Roi. As will be seen by fig. 19, the cover is full of closely set strands of crimped wire, the points of which project slightly above the tread, and thus present a rough surface to the road. It is claimed that not only is side-slipping prevented, but that the cover is also more durable and less susceptible to punctures. As to its behaviour at high speed no evidence is available.

The Wilkinson.—At the Wilkinson Tyre Manufactory, Huddersfield, is made a somewhat similar tread, which can be solutioned on to any cover. The wires in this case, however, are straight, not crimped, and are less numerous; they are also stronger individually, and project further. The tread is made in three sections, and as the wires are worn down the rubber of the external section can be pulled away, the process being repeated after further wear. On light cars there is evidence to show that this tread is satisfactory, and really prevents skidding, even in bad grease, but it has not yet been tried on fast and heavy cars.

The fact that solid tyres are considerably cheaper than pneumatics, and, of course, immune from puncture troubles, causes many automobilists to make experiments in that direction. As mentioned at the outset, however, the solid tyre is most conspicuously wanting under the very conditions when the pneumatic may seem least desirable, but is really the superior type. The problem is curiously complex. On a light, slow car, of the old Benz type, solids may safely be used; on a light, fast car the mechanism will suffer and the passengers' comfort be affected. With a heavy car the need for solids becomes greater so far as punctures are concerned, but again the demands of the car itself and the passengers assert