1530 
Empirically, the lower pressure range results of 
12 13 
Arons and Halverson can be expressed in the form ~~: 
iC (ie a6 fore) fi 
where P is the shock wave peak pressure in lb./in®. 
Comparing equations (99), (100), and (101), we obtain: 
ie -6 
: ha ji [ ern FOS RF Bae 
Combining equations (98) and (99) and expanding to first order 
terms; 
() = Age = —2.24 *10°? Pe. ff 
AR Ap \. (103) 
The empirical pressure-distance relation for TNT isl4; 
Devele (eo eae it 
(104) 
where W is charge weight in pounds and R is distance in feet. 
Substituting (104) into (103): 
r re 473 
€4) = - 9.84(10° (Me) sec. ff 
’ 
(105) 
9.4 A complication is now introduced into our consideration 
of the viscous effect on the rate of change of rise time with 
distance. The variable X which in section 8 was simply 
