o>i Mosquito Extermination. 17 



weeds, and undergrowth, while in other cases it was difficult 

 to keep the oil on the surface of exposed ponds where it could 

 be blown ashore by winds. 



Altogether, the results on the higher levels, both of oil 

 treatment and drainage, were eminently successful. In cer- 

 tain regions, which were so infested with mosquitoes that one 

 could scarcely walk through them, the pest was so completely 

 removed that scarcely a mosquito could be found. The oil was 

 a temporary expedient, the drainage a permanent one. 



The great difficulty, however, was found in the marsh areas 

 bordering New Creek behind the beaches. There the areas 

 were too large for the proper application of oil, and though 

 it was industriously applied the frequent tides carried it away. 

 There were also large areas which could not be reached by any 

 appliances at hand. 



The prevailing winds would blow a sufficient supply of 

 mosquitoes from these marshy areas to the near-by residence 

 districts to reduce the apparent value of the successful work 

 done on the highlands. During the remainder of the season 

 in question, the only mosquitoes found in abundance were 

 those known to breed in brackish water. 



It became obvious through the experience gained on this 

 area that the true remedy lay in dyking the mouth of New 

 Creek just above the beach line, and with flood gates lower the 

 water level in the marshes behind the beach to practically the 

 level of mean low tide. Such dykes are, of course, common in 

 ether countries, and some of the dykes built by the early Hol- 

 landers on Staten Island are still in service. 



Arrangements were being slowly and with great difficulty 

 perfected to accomplish this dyking of New Creek when Rich- 

 mond County became the Borough of Richmond in Greater 

 New York. The processes of administration changed, result- 

 ing in new conditions which have since held this work in 

 suspense. 



It is hoped and intended, however, that it shall proceed at 

 an early date, and when done it will offer an exceptional op- 

 portunity to show what can be done in a community of suffi- 

 cient size to demonstrate the eft'ectiveness of methods, and for 

 reasons which are obvious, upon observation of the area it can 

 be done for a nominal expense as compared with the cost in 

 manv other situations. 



