284 POPULAR SCIENCE MONTHLY. 



eliminate mosquito breeding places; but that sort of reclamation is 

 expensive and the total bill would be so great as to make it impossible 

 to obtain consideration from any legislature. For the purpose of 

 preventing mosquito development, reclamation is not necessary; it 

 needs only such works as will enable all surface water to drain off 

 completely in less than a week, or as will fill all depressions to a 

 general level, whatever that general level may be. 



The average marsh bottom is a tough clayey mud of variable depth, 

 overlaid by a turf from six inches to a foot or more in thickness. This 

 material is like a huge sponge from which the water will run out 

 if it gets a chance, and which will absorb an enormous quantity of 

 surface water. Its texture is also such that it will maintain even a 

 narrow ditch perfectly and, if it is deep enough — two feet or more — 

 no growth will start from the bottom. For slow drainage a ditch six 

 inches wide, that will affect from thirty to fifty feet on each side can 

 be cut by machine, and will dry off even the heaviest precipitation of 

 rain in twenty-four hours. If a spring tide soaks the marsh the drain- 

 age is slower; but the surface will be free of shallow pools within 

 forty-eight hours. 



Lest it should be considered that this is all a statement of belief 

 merely it should be said that in 1903 several bad areas near Newark 

 and Elizabeth were experimentally ditched. When the work was 

 begun the marshes were soft, full of holes, water-logged and hip boots 

 were a necessity. The crop of salt hay could not be gathered until 

 winter and lawn shoes for horses where they could be used at all, were 

 a necessity. Throughout 1904 it was possible to walk over the 

 drained area at all times, dry-shod except after heavy rains, and then 

 twelve hours were enough to dispose of every pool or puddle. The 

 crop of hay was heavier than for many years past, much of it was 

 cut by machine and horses could be taken everywhere. Practically 

 no mosquitoes developed on these areas. 



The most convincing work however was. done on the Shrewsbury 

 Eiver, extending from Seabright to North Long Branch and including 

 nearly all the marsh area on both Monmouth Beach and Rumson neck 

 sides of the stream. The territory had been roughly surveyed dur- 

 ing the season of 1903 under the direction of local associations, and 

 during the winter, at the request of these associations, one of the 

 field agents and afterward an engineer was sent down to lay out a 

 general drainage scheme. Before even the frost was out of the ground 

 work was begun, and very soon afterward, in early March, wrigglers 

 made their appearance in every pool and millions of potential 

 mosquitoes were on the marsh. But the weather remained cold, larval 

 growth was slow and the work was systematically pushed so as to 

 reach the worst places first, the sods removed from the ditches being 



