1887.] NE"W YORK ACADEMY OF SCIENCES. 81 



a specified sum per foot the sinking of an artesian well to any 

 reasonable depth, yet the great cost and the uncertainty of 

 success of any one boring, as regards the volume of water 

 which may be permanently obtained, have caused this method of 

 search for water to be adopted for cities and towns only as a last 

 resort. 



If it be proper to classify the systems which have been re- 

 ferred to as the "artesian^' and the "driven well" systems, it 

 can be said of the latter that the methods of exploration and 

 well-sinking which have been recently developed seem to ofEer 

 incontestable advantages, and to promise results of the greatest 

 value and importance. Facts have been established, in the ex- 

 plorations already made in different jolaces, which seem to offer 

 strong inducements for further and systematic researches, not 

 only from an economic, but from a scientific point of view. 

 Among the scientific questions presented, those which appear to 

 be of special interest relate to the causes of some of the peculiar 

 phenomena of deposition and arrangement presented in the in- 

 terstratified beds of gravel, clay, and sand which are found to 

 exist ; and, if these are connected in any way with ancient river 

 beds, the possibility of tracing out these beds with greater cer- 

 tainty. 



A study of these surface deposits by the methods which 

 have been introduced for the driven wells, and which are attended 

 with little difficulty and expense, comparatively, seems to offer, 

 at least, an attractive field for economic and scientific explora- 

 tions. 



Through the kindness of Mr. W. D. Andrews I have ob- 

 tained sketches which illustrate the construction of one of the 

 four "plants" on Long Island from which the supply above- 

 mentioned is obtained, and also a sketch illustrating the pro- 

 cess of boring or prospecting adopted ; and another repre- 

 senting a section of the deposits of sand, gravel, and clay in the 

 vicinity of one of these plants to the depth of 433 feet. 



In these sketches. Fig. 5 represents a plan of the whole 

 "plant." The system of driven tubes occupies a space about 

 800 feet long and 15 feet broad, parallel with the line of the 

 Brooklyn aqueduct. The tubes are in two rows about 15 feet 



