1562 
and spread of the profile and add the spherical effect of sas 
we would expect a pressure-distance dependence of the form 
es ee ein for 0.5 lb. charges 
(147) 
Fay 7 Roe for 300 lb. charges 
This calculation omits a small contribution from the residual 
Rankine-Hugoniot dissipation. 
Most experimental peak pressure similarity curves have 
been found to have exponents of 1-13 to 1.15, and the results 
reported in NavOrd 42422 show that this slope persists into the 
low pressure region to which the calculations leading to equations 
(147) apply. 
Our interpretation of this result is that in the high 
pressure region the contribution of 0.13 to 0-15 to the exponent 
comes from the combined effects of spread of profile and Rankine- 
Hugoniot shock dissipation. As the range increases, the Rankine- 
Hugoniot effects drop off, and the slope would tend toward the 
magnitude of 1.06 as given by the asymptotic theory; but it is 
in this region that viscous effects become appreciable, and 
apparently take over most of the role initially played by 
Rankine-Hugoniot dissipation in such a way as to make departures 
from the straight line on log-log paper undetectable within 
experimental error. 
IV. Distortion associated with reflection from the sea surface. 
15- Introduction 
15.1 In the derivation of equation (19) it was tacitly 
assumed that the wave reflected from the sea surface was 
simply inverted without distortion or attenuation. This 
=~ 8 ~ 
