Continuity 63 



experiment, and given by the theory, is 

 equivalent to a shrinkage of the earth's 

 diameter by rather less than three inches, 

 in the line of its orbital motion through 

 the ether of space. An oblate spheroid 

 with the proper eccentricity has all the 

 simple geometrical properties of a station- 

 ary sphere; the eccentricity depends in 

 a definite way on speed, and becomes 

 considerable as the velocity of light is 

 approached. 



All this Professors Lorentz and Lar- 

 mor very soon after, and quite independ- 

 ently, perceived; though this is only one 

 of the minor achievements in the electri- 

 cal theory of matter which we owe to 

 our distinguished visitor Professor H. A. 

 Lorentz. 



The key of the position, to my mind, 

 is the nature of cohesion. I regard co- 

 hesion as residual chemical affinity, a 

 balance of electrical attraction over re- 

 pulsion between groups of alternately 

 charged molecules. Lateral electrical 

 attraction is diminished by motion; so 

 is lateral electric repulsion. In cohesion 



