184

FRICTION OF CARRIAGES

Plate II. Plat bearing surface 2-~ inchesbroad, 3 feet 9^ inches long; the plane, apiece of road selected for the purpose, wasquite straight, and with a uniform inclinationof .0738 inches in a yard, or one yard in 488.The carriages were the same as used upon theroad for the conveyance of Coals , and similarto that shown in Fig. VII. Plate IV. Thewheels were fixed upon the axles, and turnedwith them ; their diameter w as 34 inches, witha projecting ledge of three-quarters of an inch,to keep them upon the road.—The body of thecarriage rested by a chain of brass or iron,upon the axles of the wheels, as explained inthe detail of the experiments ; the axles beingof w r rought-iron, 2$ inches diameter at thebearing.