The strength or weakness of wheels plays an important part in the durability of the vehicle, for in whatever manner the various forces are mechanically met they at last concentrate themselves on the wheel; it is highly necessary, therefore, that great pains should be taken in constructing them. The stock is not necessarily the foundation on which to build a wheel, and, further, there are many objections to its being so constituted. In the first place, when its centre is all scooped out for the reception of the axle-box, and its sides are mortised out to receive the ends of the spokes, it is nothing but a mere shell. Every mortise hole is more or less a receptacle for water, which the best workmanship cannot wholly exclude; and as one part of the stock is always more porous than another, that is the part that will soonest absorb wet and begin to decay. If, therefore, the stock could be dispensed with greater durability would be insured. [Illustration: Fig. 16.] [Illustration: Fig. 17.] A thoughtful inventor, turning over these things in his mind, has, during the last few years, produced a wheel of novel construction, which is found practically to be superior to the one in common use. All the spokes, instead of being shouldered down to enter the stock, are made wedge-shaped at the end, and instead of the wheel being constructed from the centre to the felloe, it is constructed from the felloe to the centre. Every felloe is made and fitted with its two spokes, which, as they converge towards the centre, press upon each other in such a manner that when the whole periphery is put together a solid centre is produced by the spokes themselves, as shown in Figs. 16 and 17; so that instead of being dependent on wooden stocks the spokes are dependent upon each other, and by being tightly wedged together create a mutual support and resistance. The whole are secured by two metal flanges, one at the back and one at the front of the centre of the wheel, which are tightly screwed up, by which means the greatest amount of solidity is obtained for the entire structure of the wheel.