1548 
measure the energy flux of both the incident wave and the 
bottom reflection for various angles of incidence up to the 
critical. The flux in the bottom reflection was corrected to 
the same radius as the incident flux,and the measured ratios 
of E/ 24 are given in Table II. The observed ratios are com- 
pared with theoretical ratios based on the result of acoustical 
theory: 
2 
C 20 7; 
(ae Cos 6, - (/- oe Sin*8 ) z 
Ae, ae 
Theoretical E/E, = (124) 
set seal, (& 2 4 
fe 2556,+ (1- Ss 5/n*6,)* 
(: Cc, (Bie 
In accordance with the discussion of Chavter I, (2/2: was 
taken as 2.7 and Cp/C; as 1.15. 
It is evident in Table II that the observed ratio 
E,/Ei is in general significantly lower than that given by 
equation (124). This could be adjusted at lower angles of 
incidence by using somewhat lower values of 2 // 9 but such 
an adjustment would not serve to explain the fact that the observed 
ratio remains less than unity even when the critical 
angle is approached or exceeded. It is probable that the low 
values of observed E,/E; indicate substantial energy lass to 
inelastic processes and absorption occurring at the reflecting 
interface. 
12.2 Energy flux ratios were measured rather than amplitude 
ratios in order to take advantage of the smoothing or averaging 
afforded by the integration process. An average amplitude ratio 
STS 
