142 



EXPERIMENTS ON CENTRIFUGAL FORCE. 



to it, it will rotate, when the motion begins, in il 

 vertical position; but as soon as the rotation become 

 more rapid, or if the disc be ever so lightly touched 

 and thereby displaced from the vertical position, th< 

 centrifugal force drives the opposite sides of the disc a^ 

 far as possible from the axis of rotation, and causes the 



FIG. 100 (an. prof. real size}. FIG. 101 (an. proj. real size) 



disc to place itself horizontally, as in fig. 101. In thi 

 interesting experiment the centrifugal force becomes 

 with sufficient velocity of rotation, so powerful as t 

 overcome the force of gravitation. 



The little hook is bent of a short piece of wire. The ends ai 

 pushed through two holes punched on opposite sides of the centr 

 and the projecting portions are then bent at right angles with tl 

 flat pliers, or the ends may be twisted. 



