SALT MARSH DRAINAGE 157 



to bring the water to the pump and to take it away arc engi- 

 neering questions that can only be decided by a competent 

 engineer after detailed study of the particular problem. 



In parts of Hudson County, New Jersey, where the meadow 

 elevation is very near mean sea level or lower and in the low- 

 lying marshes near Philadelphia, Pa., very excellent systems of 

 pumping have been worked out. These pumps are electrically 

 driven and are automatic in operation, being regulated as to 

 starting and stopping by a simple float, which is raised or lowered 

 by the water on the marsh, and starts or stops the pumps accord- 

 ingly. 



A 12-inch low-head centrifugal electrically driven pump, 

 installed in a low area of Hudson County, N. J., in 1915 at a 

 cost of about SI ,300, satisfactorily drained a territory of about 

 700 acres at a cost during the mosquito season of about $80 a 

 month. 



