IX.] 



POBMS OF PROMINENCES. 



115 



The different forms which these prominences assume some- 

 times are very striking. Here one is reminded, by the fleecy, 

 infinitely delicate cloud-films, of an English hedge-row with 

 luxuriant elms ; here of a densely intertwined tropical forest, the 

 intimately woven branches threading in all directions, the pro- 

 minences generally expanding as they mount upwards, and 

 changing slowly, indeed almost imperceptibly. 



It does not at all follow that the largest prominences are those 

 in which the intensest actions, or the most rapid change is going 



FIG. 47. Solar prominences (Young), showing lateral currents. 



on. The greatest action is generally confined to the regions just 

 in, or above, the chromosphere. 



This and subsequent observations led me to propose a division 

 of prominences into two classes : 1 



1. Eruptive. Those in which great action is going on, lower 

 vapours being injected ; in the majority of cases these are not 

 high, they last only a short time are throbs, and are oft 

 renewed. They often accompany spots, but are not limited to 



1 Proc. Roy. Soc. No. 120, 1870. 



I 2 



