PERPETUAL MOTION. 



is embodied in the corpuscular vibrations of 

 comparatively few atoms, and liberated by 

 their disintegration. 



3. A Clock which is Never Wound and Never 



Stops. 



The radium clock, as it is somewhat fan- 

 tastically called, an invention 

 of the Hon. R. J. Strutt, is 

 another instance of what 

 appears to deserve the name 

 of perpetual motion. 



A half-size sketch of it is 

 shown in Fig. 40. 



It consists of an electro- 

 scope suspended from the 

 lower end of a small glass 

 tube containing a little 

 radium of about the size of a 

 wall-flower seed. This 

 is fastened to the top 

 of a larger glass ves- 

 sel, which is a vacuum 

 tube that is, has had all the air pumped out 

 of it before it was sealed up. The action is as 

 follows : 



Among the things which come from the 

 atoms of radium on their disintegration are 

 the alpha rays. These are, for small things, 

 somewhat large groups of corpuscles, and, for 

 swift things, somewhat slow missiles, flying out 



ifti 



Fia 40. THE RADIUM CLOCK 

 PERPETUAL MOTION. 



