How did Robert Boyle prove experimentally that in vacuum, all bodies fall at the same rate?
Boyle's experiment: 
Fig. Boyle's experiment of coin and paper (a) in vacuum, (b) in air.
i) Robert Boyle took a long glass tube, a heavy coin and a piece of paper were placed inside it as shown in the Fig. below
ii) The ends of the tube were closed and air of the tube was removed by a vacuum pump.
iii) When the tube was quickly inverted, it was observed that both the coin and the paper hit the bottom at the same time.
iv) On repeating the experiment with air inside the tube, it was observed that the piece of paper falls slowly while the coin hits the bottom immediately.
v) thus, Galileo's assertion was proved, that in vacuum all bodies irrespective of their mass fall towards the earth with the same acceleration.
