GROUND-WATER INVESTIGATIONS—SAYRE 225 
ing rapidly in the middle thirties. In 1935 the total use of ground 
water in the United States amounted to about 10 billion gallons a day. 
The development was greatly accelerated by the needs of the war, 
so that by 1945 the total pumpage had nearly doubled.2 Although 
the war ended more than 2 years ago there has been no sign of a 
decrease in the use of ground water. In fact, both surface water and 
ground water are now being used in greater quantities than ever 
before. As the use of water approaches ever more closely the limits 
of the available supply, it is believed that water-resources investiga- 
tions will be needed with ever-increasing urgency because water 
constitutes the prime factor in the continued development of the 
Nation’s industrial and agricultural economy. 
§ Guyton, W. F., Industrial use of ground water in the United States. Abstract, Journ. Washington 
Acad. Sci., vol. 39, No. 3, pp. 105-106, Mar. 15, 1949. (To be published in Proc. Geol. Soc. Amer.) 
