xxviii.] CONES. 437 



to great heights; and, besides these, the production of 

 streamers. Two results must follow from this which we have 

 already referred to, viz : 



1. In consequence of the increased temperature of the lower 

 regions, the velocity of the lower currents towards the poles, 

 and therefore of the upper currents from the poles, is enormously 

 increased. 



2. Violent up-rushes of the heated photospheric gases, mount- 

 ing with an initial velocity of a million miles an hour, will also 

 produce local disturbances in the upper atmosphere. 



FIG. 131. The eclipse of 1858, showing cones. 



In this way, the sudden rise to maximum in the sun-spot 

 curve, and the lowering of the latitude of the spots, follow as a 

 matter of course from the unequal strength of the currents 

 from the pole. 



Does the hypothesis explain then the slow descent to 

 minimum and the still decreasing latitude ? It does more, it 

 demands it. For now the atmosphere over those regions where 

 the spots have hitherto been formed, is so highly heated, and its 

 height is so increased, that any disturbed material descending 



