Atwood Machine

This was in the Whipple Museum of the History of Science in Cambridge. I used to do calculations based on two masses joined by an inelastic cord and hanging over a frictionless pulley. This equipment gets real results for that. Mass M1 is pulled downwards by gravity and upwards by the Tension T. Resultant force M1.a = M1.g - T. If mass M2https://en.wikipedia.org/wiki/Atwood_machine
 says that elevators and funicular railways are approximations to the Atwood Machine.