FROM CART TO AUTOMOBILE 



THE use of the wheel as a means of reducing 

 friction dates from prehistoric times. The 

 introduction of this device must have 

 marked a veritable revolution in transportation, but un- 

 fortunately we have no means of knowing in what 

 age or country the innovation was effected. We only 

 know that the Chinese have used wheelbarrows and 

 carts from time immemorial, and that sundry very 

 ancient pictures and sculptures of the Egyptians and 

 Babylonians prove that these peoples were entirely 

 familiar with wheeled vehicles. 



The earliest form of wheel was doubtless a solid disk, 

 and such a wheel is still in use in many places in the 

 East; but the wheels of the Assyrian chariot were 

 spoked after the modem fashion, and provided with 

 rims of metal. The introduction of the wagon spring, 

 however, was a comparatively modem innovation. 

 The use of springs very considerably reduces the re- 

 sistance, thus adding to the efficiency of wheeled vehi- 

 cles; but the reduction is not very obvious unless the 

 roads are tolerably good, nor is it probable that the 

 ancient nations could readily have measured the effect 

 even had the idea of springs suggested itself. 



