176 



JOHN CLARK AND RONALD EISLER 



So'! water 



— ■"""^^lE'L '•t'W 



Figure 2. — Relation between fresh water and salt water in water-bearing sands when not disturbed 

 by pumping: A, U-tube .showing balanie between two liquids of different specific gravities; 

 B, section through an island composed entirely of sand and surrounded by salt water; C, sec- 

 tion through a sand island underlain by impervious material ; D, section through a coastal plain 

 composed of alternate layers of pervious and impervious materials. (From Barksdale, Sund- 

 strom & Brunstein, 1936 — Supplementary Report on the Ground-Water Supplies of the Atlantic 

 City Region; fig. 5, p. 26.) 



