442 THE CHEMISTRY OF THE SUN. [CHAP. 



photosphere ; from that point where the surface of the ring enters 

 the atmosphere, some distance farther down. 



The American photographs in 1878 supply us with ample 

 evidence that this will be somewhere about latitude 30, and 

 here alone will the first spots be formed ; the reasoning being the 



FIG. 134. Tracing of the results obtained by the cameras in 1878, showing inner 

 portion of equatorial extension, and how the surfaces of it cut the concentric 

 atmosphere in lat. 35 N. and S., or thereabouts. 



same as that employed when we considered the atmosphere alone 

 without the ring. 



(1) Above latitude 30, as a rule, we shall have no spots, 

 because there is no ring, and further, the atmosphere is of lower 

 elevation ; so that there is not sufficient height of fall to give 

 the velocities required to bring down the material in the 

 solid form. 



