104 



to photograph it. The plate was exposed ten minutes, but 

 there was not the slightest trace of anything on it. 



The adjoining cut represents tlie apparatus employed, 

 except that the receiver was replaced by the globe described 

 above. The light round the ball gives a fair idea of the 

 momentary appearance, and it is impossible to represent 

 more, as this flickers and changes so rapidly. 



This corona when compared with the solar corora has the 

 special features — 



1. The rifts and general radial appearance, including the 

 bending and crossincr of ravs. 



