Dr R. A. Millikan 163 



being flung off into space. Yet nothing was found to 

 upset the belief that our solar system, presumably like all 

 other solar systems, was doomed to eventual dissolution. 

 The discoveries made only tended to give a clearer idea of 

 the ways in which energy was dissipated. The matter was 

 put in a nutshell by that brilliant writer and scientist 

 Professor Jeans, who wrote : 



Mass is converted into radiant energy, but that process is 

 nowhere reversible. Matter will thus ultimately be all con- 

 verted into radiation — i.e., it will simply disappear. . . . Thus 

 observation and theory agree that the universe is melting away 

 into radiation. Our position is that of polar bears on an ice- 

 berg that has broken loose from its ice-pack surrounding the 

 pole and is inexorably melting away as the ice-berg drifts to 

 warmer latitudes and ultimate extinction. 



Then came a glimpse of something new. In 1903 

 M'Lennan and Rutherford discovered certain radiations 

 near the earth's surface so penetrating that they were 

 capable of passing through thick screens of lead. Profes- 

 sor Jean Perrin, who holds the chair of physico-chemistry 

 at the University of Paris, was greatly interested, but 

 unable to decide upon the source or nature of these rays. 



In 1910 the Swiss scientist Gockel went up in a balloon 

 to a height of more than three miles, taking with him an 

 enclosed electroscope (the instrument used for measuring 

 electric discharges), and what he found was that at this 

 height the radiation was stronger — far stronger than 

 nearer the earth. So its source, it seemed, was some- 

 where outside the atmosphere of this planet. Hess, in 

 Austria, and Kolhorster, a well-known German scientist, 

 made similar experiments. 



The latter sent up an electroscope to the great height of 

 nearly six miles, and found that the power of these new 

 rays was actually seven times greater there than on the 

 ground. After further investigations he announced his 



