7. Cumulonimbus, L3. 



The anvil is fully developed and its edges are frayed out. Cumulus 

 clouds of a lighter shade appear against the gray cf the anvil; at the 

 center, they are mergmg with the cirrus mass. Below, there is a roller 

 of dark fractocumulus. The anvil alone, after the cumuliform parts 

 have disappeared, would be coded //s (pi. 44), but in this picture the 

 cloud is coded U. (Photo at Washington, D. C, by P. A. Miller.) 



8. Cumulonimbus, L3. 



Here the cumulonimbus is shown as a regular "factory of clouds." 

 The cirriform parts (H3) of anvils extend overhead and beyond the 

 limits of the photograph. The principal mass appears to be only 

 one of several cumulonimbus clouds in the vicinity. This one has not 

 advanced far enough to be coded X9. (Photo at Pensacola, Fla., by 

 Air Service, U. S. Navy.) 



44 



