Eight-Year Cycle in Relation to Physical Cause 137 



(1) The significance of the newer theories of electric- 



ity as a means of explaining the mode of 

 action of the Sun upon the Earth is only be- 

 ginning to be realized. 



As an indication of progress I should note, 

 in addition to what has already been said, 

 the new view as to the nature of the inter- 

 planetary medium. In 1896 when J. J, 

 Thomson and Roentgen were extending the 

 researches of Crookes, Schuster raised the 

 important question as to whether the inter- 

 planetary medium could transmit an electric 

 current : 



''Speculative theories on the magnetic and 

 electric relationship between the Sun and 

 Earth lack all solid basis until we can give 

 an answer to the question, whether inter- 

 planetary space is to be considered an elec- 

 tric conductor or not." ^ 



A quarter of a century later, in 1921, Dr. 

 Bauer could make this reply: " . . . the 

 evidences are getting stronger and stronger 

 that interplanetary space, as the result of 

 solar radiations and emanations, may indeed 

 be an electric conductor, the possibility of 

 which Schuster suggested." ^ 



(2) Even now there is no adequate provision for 



the observations of the essential phenomena. 



1 Terrestrial Magnetism, vol. 1, 1896. Quoted jjy Dr. Bauer: "Meas- 

 ures of the Electric and Magnetic Activity of the Sun and the Earth, and 

 Interrelations." 



Terrestrial Magnetism, March and June, 1921, p. 37. 



- Bauer, Ibid., p. 38. 



