In the groove of the pulley there is a silk string passing through two holes in the platform, at the ends of which there are two identical, perfectly balanced objects.
One of the two objects is placed on a metal disk (diameter 5.8 cm) that can be tilted and which is attached to the zero of a vertical graduated rule placed between the two columns.
Behind the two columns and the graduated rule there is a pendulum free to swing composed of a thick, brass-plated lens having a diameter of 16.3 cm and a suspending rod 106 cm long.
A lever attached to one of the columns holds the pendulum at rest in the position of the maximum range of oscillation.
If after placing another object on the one lying on the metal disk the pendulum lever is lowered, the pendulum begins swinging and, simultaneously, the disk overturns, freeing the two objects which fall vertically under the weight of the added object, with an acceleration given by the ratio between that weight and the overall mass of the three bodies in movement. ...continues