1906.] GEOLOGY IN RELATION TO WATER SUPPLY. 297 



and lowlands, so that as the material is now found it has the 

 appearance of water deposits rather than glacier deposits. 

 Because of its method of deposition stratified drift is always in 

 layers and the coarse material and fine material are separated 

 from each other. Layers of coarse gravels and sands of dif- 

 ferent grades and classes are interbedded, and a section cut 

 through the stratified drift shows ordinarily considerable varia- 

 tion in texture. These sands and gravels contain a large 

 amount of pore space and water occupies them up to 30 or 40 

 per cent, of their volume. Sands are the great water-bearing 

 beds and wells sunk in them below the level of the ground 

 water are certain to have an adequate supply. However, the 

 level of ground water in sand is liable to fluctuate more than 

 that of bowlder clay or bed rock, and it is advisable to sink 

 wells to a depth somewhat below the water table. So great 

 an amount of water is contained in stratified drift that it is the 

 custom in Connecticut to sink a number of wells in close prox- 

 imity to a considerable depth below the level of ground water 

 and to use them as a single reservoir. For instance, on the 

 New Haven plain the sands are saturated at a depth of less 

 than 20 feet, and wells sunk to depths below that point have a 

 supply of water in proportion to their depth. The gymnasium 

 at Yale University is supplied by twenty of these wells driven 

 closely together. 



The water supply of Connecticut constitutes the mineral 

 wealth of the State. Abandoned lands are being bought for 

 summer homes and the essential condition of purchase is an 

 adequate and satisfactory water supply from lake, spring,_or 

 well. Moreover, there are few farms in the State which would 

 not give greater yields of hay and grain crops if the amount 

 of available water were increased. I expect to see the day 

 when irrigation is generally practiced in Connecticut. There 

 is abundant water in rivers and lakes for the purpose ; it needs 

 only to be differently distributed. A careful detailed study of 

 the water supply of the State and of the geological factors 

 which control it would, I think, result in added wealth of crops 

 and added value of the State as a summer resort. 



