330 
region of Cumulus and Cumulus congestus seem- 
ingly leading into the storm, the cells growing 
larger the nearer to the storm mass they are. 
These clouds and their relation to the main storm 
are also seen in Figure 3. At the juncture of the 
western edge of these clouds with the area of 
precipitation a dark sloping line is visible, bor- 
dered by two bright lines. This configuration is 
assumed to be the result of a vortex circulation, 
ROBERT M. CUNNINGHAM 
the precipitation particles being concentrated 
on the perimeter of the vortex. This apparent 
vortex was short-lived; it is not visible on Photo 
SS (taken one minute previous) ; and it appears 
about double the size but very faintly on Photo 
No. 90 (taken one minute later). One may im- 
agine that the Cumulus cloud material on the 
right is streaming into the storm while the pre- 
cipitation is flowing out and that the region of 
Gad 
Enlargement of part of Photo 89 
