GEOLOGY OF THE NEW YORK CITY AQUEDUCT 



239 



somewhat unusual quality of material at this place as indicated by 

 the wash and core saved and because of the suggestion it gives 



^ / / / / # a \i\ I )/ // iririr 



Fig, 38 Key map showing plan of exploratory borings at the Harlem 

 river crossing, location of the New Croton aqueduct which crosses the 

 Harlem in a pressure tunnel and the Old Croton aqueduct which crosses the 

 river on High Bridge 



about the structure and condition of rock beneath the river, the 

 record and interpretation notes are given. 



