Demonstrates that objects fall at the same speed, regardless of weight, in a vacuum. Consisting of a 16mm diameter glass tube 50cm long, fitted with two rubber bungs, and a 40cm length of tube for connection to a vacuum pump. Two objects with different weight and air resistance (e.g. a mass and a piece of paper or a feather) can be placed at the foot of the tube, and when inverted the objects will fall back to the bottom of the tube at the same rate – in a vacuum. Further studies of the effects of air resistance can be carried out, such as timing the fall of paper through variations of air pressure in the tube, to gauge the effects of air resistance on the acceleration of an object under gravity.