1290 
connection the essential differences between water-like 
substances and ideal gases are noteworthy. 
The experimental evidence is still fragmentary, but for 
water it shows definitely the existence of the expected 
higher-than-head-on pressures for oblique, regular reflection 
and of the Mach effect. There is included a brief survey 
of the experimental work done to date at Oxford, England; 
at the David Taylor Model Basin, Carderock; at the Explosives 
Research Laboratory, Bruceton; and at the Underwater Explosives 
Research Laboratory, Woods Hole. 
