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public opinion could be aroused to the necessity for it. It be- 

 came, therefore, necessary to determine the general direction of 

 flight and the conditions which govern it, in order that the 

 ditching, which the Commission in Atlantic County, aided by 

 the State, should cut, could be placed most advantageously from 

 the standpoint of giving the principal centers of population the 

 largest amount of relief. Mr. Eaton, the Chief Inspector of 

 the Atlantic Commission, took the problem in hand in a vigorous 

 manner and secured a number of voluntary observers located in 

 different parts of the county, who agreed to furnish him with 

 the time when mosquito broods made their appearance. He 

 also obtained from the Weather Bureau a record of the speed 

 of wind, relative humidity of the air and the precipitation 

 throughout the mosquito breeding season of 19 14. By a study 

 proceeding along these lines, supplemented by observation the 

 writer was able to make in other parts of the State, it became 

 clear that mosquitoes travel with winds of low velocity (10 

 miles an hour or less with a probable optimum of 5), high 

 relative humidity (80% or more) and warm temperature. 

 Tine same study served to show that the winds of this type come 

 almost entirely from the west, southwest and southeast. Of 

 course, the winds from the southwest and west were the only 

 ones which would serve to bring into Atlantic City large num- 

 bers of mosquitoes. Accordingly, the Atlantic County Commis- 

 sion centered its efforts on draining the Atlantic County marshes 

 from a point north of Atlantic City, southward along Somers 

 Point and up the Great Egg Harbor River and its branches, and 

 the result has been that with only a small percentage of the 

 marsh drained Atlantic City and even Pleasantville and the 

 Shore Road to the south have largely been freed from serious 

 trouble. 



During the summer of 191 5 an investigation of the local 

 mosquito problem at Princeton, N. J., has served to show that 

 the ordinary methods of studying the distribution of mosquitoes 

 on the wing, which applied to the salt-marsh species and to the 

 house species, will not work for the malarial species. Night 



