1476 
Abstract 
The theory of oblique reflection of low amplitude 
exponential shock waves is considered in more detail than in 
the preceding report (NavOrd 424) and is extended to include 
higher order reflections in shallow water. Errors arising from 
use of the plane wave approx niaton are discussed. 
Recently published data on the attenuation of harmonic 
sound waves in sea water are used to develop a theory of the 
effect of viscous attenuation on the front of a shock wave 
propagating over long ranges. Crude correction is made for the 
compensating effects of finite amplitude. 
Experimental data on impulse and energy flux at long 
ranges are reported. The energy dissipation is analyzed in 
terms of the theory of viscous attenuation and an attempt is made 
to account for the siope of the pressure-distance curve. 
Experimental data on negative gauge pressures in surface 
reflections are reported and analyzed in terms of a new treatment 
of the expected region of bulk cavitation. The data indicate a 
very low value of the "breaking tension" of sea water. 
An improved microcoulometer circuit for the calibration 
of piezoelectric gauges is described. 
So Val 
