136 



EXPERIMENTS ON CENTRIFUGAL FORCE. 



sented in fig. 99. The two uprights of the frame are 

 connected by a crossbar, which is fixed about 3 cm above 

 the foot of the frame. 15 mm above this bar each 

 upright is pierced by two parallel holes, about 10 or 

 15 mm distant from one another, and rather narrow. 

 Two equal cylinders, one of wood, the other of cork, 

 about 2 or 2 C1B *5 long, and of the same diameter, are 

 also pierced by parallel holes, having precisely the same 



FIG. 98 (an. proj. ^ real size). 



distance between them as those in the uprights. 

 Two threads are passed in the manner shown in the 

 figure through the cylinders, stretched tight, and fixed 

 by their ends to the uprights. A third thread, from 4 

 to 6 cm long, connects the centres of the two cylinders, 

 and keeps them at a certain distance apart. If both 

 cylinders are placed as shown in the figure, so that each 

 may be equally distant from the nearest upright, and 

 the apparatus be set in motion, the sound of something 

 striking against the frame will be heard very soon. 

 When the apparatus has been allowed to come to rest, 

 it will be found that the wooden cylinder has moved 

 close to the nearest upright. The heavy piece of wood 

 has manifested a greater centrifugal force than the 



