Description
"The Atwood machine consists of a wheel or pulley, R, over the grooved edge of which are balanced two equal weights suspended by a long silk thread which is both light and strong. The axle of this wheel is preferably supported upon the circumfrences of four friction wheels, r, r, r', r', for greater delicacy of motion. As the thread is so light that its weight may be disregarded, it is evident that the weights will be in equilibrium whatever their position." — Avery, 1895