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marsh. The methods by which this is to be accomplished may 

 vary from the digging of a simple systemi of lateral ditching to 

 the installation of an expensive and elaborate . system involving 

 canals, dikes and tide-gates. 



In 1906, when mosquito extermination by drainage of the 

 salt marsh was a theory rather than a demonstrated and ac- 

 cepted fact, Professor Smith, of the Agricultuiral Experiment 

 Station, recommended and earnestly advocated the drainage of 

 all the salt marsh in the State by mieans of ditches ten inches 

 wide and thirty inches deep, and so placed as to remove the 

 stagnant water from the marsh. No definite system, or prin- 

 ciple seems to have been followed in this early drainage work 

 and examinations of the marshes drained in those days show the 

 ditches running in all conceivable directions and intersecting 

 where they may. Some care seems tO' have been exercised in 

 the selection of outlets, but a common mistake was the use of a 

 ten-inch ditch as the outlet for six or eight other ditches. 

 Ditches of the width of ten inches have subsequently become 

 known as ''mosquito ditches," and this is still the standard width 

 for the present ditches. 



Continued observation on the meadows has shown that this 

 type of ditch, namely, ten inches wide and twenty-four to thirty 

 inches deep, with vertical side walls, is the most efficient for area 

 of cross section, and the most easily maintained. The width is 

 so small that the ditch can be easily bridged by hay-cutters and 

 in the firm meado\y can be crossed by wagons without being 

 bridged. Its seepage action in drawing the water fromi the sur- 

 face of the meadow on both sides of it is as great as that of a 

 wider ditch, for it is obvious that the area of cross section has 

 no relation tO' seepage action, which is principally affected by 

 depth. 



Furthermore, in the course of a year or two the width of 

 the ditch is such that the overhanging grass conceals the surface 

 in such a way as partially tO' protect it from the floating sods 

 and debris which are found in the wider ditches. It has also 

 been observed on the salt marsh that the wide ditches with the 

 sloping sides dug by the farmers for drainage purposes afford 



