1887.] NEW YORK ACADEMY OP SCIENCES. 85 



underground water-ways, rendering systematic explorations 

 necessary. 



The questions which naturally arise, concerning these de- 

 posits, are: What have been the causes of the peculiar arrange- 

 ments of sand, gravel and clay? Are the gravel deposits the beds 

 of ancient water courses, along which the finer sands and clays 

 have been washed away by the stream? Can these old river beds, 

 if they exist, be traced and identified throughout their courses? 

 In the exploration between Albany and Troy, the appearance 

 of the gravel found seems to indicate a common origin with that 

 of Utica, and it is the opinion of Mr. Knox that the same beds 

 extend along the valley of the Mohawk between these points, but 

 by a route not identical with the present course of that river. 



The mode of exploration which has been described renders it 

 more simple and less expensive than might be imagined, to con- 

 duct such researches, although not probably within the means 

 of private explorers. 



An instance has recently come to my knowledge which adds 

 new interest to this subject, inasmuch as in this case water was 

 procured in abundance from a sub-surface deposit in loose ma- 

 terial in a region where the small rainfall and the absence of 

 permanent surface streams has heretofore been considered a 

 serious obstacle to any permanent settlement of the country. 



Mr. Arthur Macy, a graduate of the School of Mines, having 

 been appointed to take charge of the famous " Silver King" 

 mine in southwestern Arizona, found that for the extensive 

 milling operations indispensable in the treatment of the ore, 

 an amount of water would be necessary for which no adequate 

 supply appeared available. A valley of several miles in extent, 

 lay above the mines, and from the appearance of the country,, 

 he concluded that this valley, from which flowed a small 

 torrent in the rainy season, must contain sub-surface water. 

 He excavated two open wells, one 15 feet and the other 25 feet 

 deep, at the outlet of the valley, and about 300 feet above his- 

 mills in vertical elevation and three miles distant from them. 



A 3-inch pipe was carried from the mills up the valley to th& 

 wells, where it was connected to two siphons, one from each 

 well ; through these siphons, without the use of pumps, he ob- 



