FALLING BODIES. 
201 
to reenter tlie tube; then the paper disk fell more 
slowly than the silver. What do these experiments 
show ? 
Is it not that all bodies fall with the same velocity 
in a vacuum,, no matter how large they are or of 
what substance they are composed ? In other words, 
“ the earth exerts upon each particle of matter sepa¬ 
rately a force which is proportionate to the mass of 
the latter, independent of the material of which it is 
composed. On the moon, which has no atmosphere, 
a feather and a bullet would fall with the same ve¬ 
locity.” 
Our third experiment was also made in the cor¬ 
ridors of the schoolhouse. First we made a pendu¬ 
lum with a lead ball and a string, that oscillated 
exactly once in a second. We did this because we 
could mark time better with the pendulum than we 
could with the watch. From the point of support to 
the center of the ball the pendulum was thirty-nine 
and one-eighth inches long. 
Then we let a ball fall from different heights, until 
we discovered, if we held it sixteen feet above the 
floor, it struck the floor in one vibration of the pen¬ 
dulum—that is, in one second. The pendulum and 
the ball were started at the same time by tying them 
together with thread about a foot long and hanging 
them over the support so as to leave both in a proper 
position. They were then released by cutting the 
thread. 
ISText we wanted to find out how far albody would 
fall in two seconds. We discovered that if the ball 
