MATTER IN MOTION 



93 



for ever. The whole is therefore in equilibrium, 

 but since the lower loop of the chain is sym- 

 metrical it could be cut off without destroying 



Figure 16 



The Frontispiece of Stevinus 

 (From Mach's Science of Mechanics) 



the equilibrium, and we should have left the two 

 balls on the one plane balancing the four on the 

 other. 



You will say that Stevinus is assuming the 

 impossibility of perpetual motion, and that this 

 is only another way of stating the same prin- 



