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if the bank is set well back, as I have suggested, this is not usually 

 necessary. Where drainage is by means of tide-sluices, these 

 should be carefully designed and constructed. They must be 

 of ample area, but not too large. They are often made too small, 

 so that the water has not time to run out during the period of 

 low tide. The lower the water is held in the meadow the shorter 

 will be the period which the drainage water can run out of the 

 sluices. Ordinarily it will vary from four to six hours at each 

 tide. 



If it is found after some years of cultivation that the marsh 

 has subsided to such an extent that it can no longer be kept dry 

 by the sluices, then pumping should be resorted to. The most 

 inexpensive pumping arrangement is made up of a centrifugal 

 pump driven by an oil or gasoline engine. Owing to the increas- 

 ing price of gasoline, however, it is better to use an engine burn- 

 ing kerosene or the heavier oils. If the operation is a very large 

 one, it may be well to use steam. A pumping plant is much 

 more economical when it serves a considerable area. As I have 

 stated before, the minimum unit should be i,ooo acres, but if a 

 larger area can be served from a single pumping station, the 

 economy will be still greater. Perhaps it is well to remind you 

 that youi should not be deterred by the fact that pumping must 

 be a continuous process once it is begun. You do not have to 

 bother about the expense of a thousand years in the future in 

 any particular year. It would be as reasonable for a farmer to 

 complain of the fact that his outlay for fertilizer must be con- 

 tinuous. 



When Prof. Headlee suggested this address, I felt somewhat 

 reluctant, for the reason that I have been accustomed to consider 

 this question only from an economical and engineering stand- 

 point. I have by no means undervalued the excellent work 

 which has been done by way of mitigation of the mosquito 

 nuisance in the State, but I have been more and more impressed 

 with the necessity that we should find a more economical and 

 permanent method of dealing with our tide marshes than mere 

 temporary mosquito ditching. If we can accomplish the elimi- 

 nation of the mosquito, while we are at the same time adding 



