1 1 



While the suffragists and the antis argue over a voting 

 woman's obhgation to bear arms, there is no such debate 

 amongst mosquitoes. The mosquito army is composed entirely 

 of females — ''the female of the species is more deadly than the 

 male." 



Hardly more than a dozen years agO' Professor Smith, the 

 then State Entomologist of New Jeisey, proposed and demon- 

 strated the efficiency of trench warfare in the enemy's country — 

 on the salt marshes — where the submarine larvae recruit the 

 bloodthirsty millions for the mosquitO' army. 



These trenches, or more properly ditches, as constructed under 

 Professor Smith's directions, were lo inches wide and 30^ inches 

 deep and were connected at one or both ends, either directly or 

 through some larger ditch, with tidewater. The illustration 

 shows a gang of three men digging one of these lo-inch ditches. 

 (Fig. 2.) 



This vertical section through the meadow surface shows the 

 meadow grass on top, the layer of sod or peat about two feet 

 thick, and the mud underneath — this mud may be anywhere 

 from one to thirty feet deep. The surface of the grass meadow 

 is slightly above average high tide — but is flooded by spring and 

 storm tides. 



Scattered over the meadows are innumerable small depres- 

 sions, or ''rotten holes" as they are called. Spring tides and 

 rains fill these holes with water, forming thousands of small 

 pools on the meadow surface, and it is from these pools that the 

 salt-marsh mosquitoes come. It is the problem of the engineer to 

 devise the most effective way of preventing adult mosquitoes 

 from emerging from these pools of water. The following 

 methods will prevent this : 



1. The hole might be filled with earth, but it is too expensive. 



2. The pool might be covered with a film of oil every week or 

 two during half the year, but it is too expensive. 



3. The water may be drained off, and this is the best method 

 to follow. 



The engineer's problem then resolves itself intO' devising an 

 effective process of drainage within reasonable cost. 



