13 ;iSEC 



104 pSEC 



54 ^SEC 



!0I jiSEC 



Plate I (top row). Photographs of spherical pentolite charges at three instants after 

 detonation. 



Plate II (second row). Photographs of cylindrical pentolite charges (4/1 length- 

 diameter ratio) at three instants after detonation. 



Plate III (lower left). Mach intersection of two shock waves at a point 12 inches 

 from two 0.11-lb. tetryl charges 8.4 inches apart. 



Plate IV (a and b, lower right). The gas products from a 56-lb. TNT charge, fired 

 100 feet below the surface, at two instants. 



