230 



THE WEATHER 



FIG. 162. A Cumulo-Nimbus, or thunder head. This cloud has begun 

 to rain, but not long ago. The longer cirrus fringe at A shows that portion 

 probably began raining before the other visible portions. 



FIG. 163. Strato-Cumulus, lower surface. Note the uneven shading. 

 The dark spots are sometimes caused by the greater thickness of the cloud at 

 those spots; sometimes by the shadows of higher clouds falling upon the 

 strato-cumulus layer. 



