1424 
The investigations of the surface reflection for an 
underwater shockwave and of the condition where the Mayer. 
corner solution fails to describe the reflection are in certain 
ways similar to the investigations of the Mach effect. There 
the conditions, under which the reflection of a shockwave by a 
rigid surface can no longer be described by the two shock con- 
ditions of incident and reflected wave, have to be determined. 
The mathematical relation between the oritical angles of in- 
cidence for both cases is derived in the last section. 
iv 
