Some of the five-gallon 

 cans which were exposed 

 by Dr. W. G. Penny's 

 Pressure Group at various 

 distances from the A-Day 

 explosion in air. Peak 

 pressures produced at 

 these distances were 

 computed from the de- 

 grees of crushing of the 

 cans. Some of the cans 

 were fastened to life- 

 preservers so that they 

 could be recovered if 

 blown overboard. 



Dr. V. E. Brock (right) and Ensign Richard Cron, Navy diver, examine 

 a camera specially designed for use underwater, as in photographing 

 damaged portions of sunken ships. This work was made difficult after 

 Test B by the potential dangers from radioactivity in the water or in 

 the ships themselves. 



Plate 9 



