56 N. J. Mosquito Extermination Association 



THIRD SESSION, FRIDAY AFTERNOON, FEBRUARY 7 



(The meeting was called to order at 2:30 p. m., by President 

 Engle.) 



President Engle: It is time that our afternoon session should 

 come to order. The first number on this afternoon's program is an 

 account of some mosquito elimination work in Pennsylvania. 



Mosquito Eradication Work of the Pennsylvania Department 

 of Health in Southeastern Pennsylvania, and its Applica- 

 tion to War Industries. 



BY FRANKLIN ROYER, FORMERLY ACTING DIRECTOR OF THE 

 PENNSYLVANIA DEPARTMENT OF HEALTH; C. A. EMERSON, 

 JR., CHIEF ENGINEER, PENNSYLVANIA DEPARTMENT OF 

 HEALTH; WM. V. BECKER, MOSQUITO ERADICATION EN- 

 GINEER, PENNSYLVANIA DEPARTMENT OF HEALTH. 



Beginning with the southern section of the city of Philadelphia 

 and extending down the river for a distance of seventeen miles, 

 the Pennsylvania shore of the Delaware lies, for the most part, 

 below mean high tide. In 1740 the Swedish settlers, who a century 

 earlier had established the first colony on this side of the Delaware, 

 began the reclamation of these tidal marshes. They constructed 

 miles of dikes along the river and its tributary streams, dug many 

 miles of ditches to drain the enclosed areas and installed tide- 

 gates to carry off the water. This work was extended and the old 

 drainage facilities maintained for many years by co-operative com- 

 panies whose charters, in some cases, antedate the Revolution and 

 whose activities extended into the present century. Finally the 

 burden upon the few remaining members of these companies became 

 too heavy, the dikes were permitted to disintegrate, the tide-gates 

 fell into disrepair, the ditches became choked with vegetal ion and 

 silt. From pleasant, prosperous farming land the major part of 

 the territory reverted to unsightly mosquito breeding swamips and 

 stagnant ditches. 



Overlapping this period of decay, came a period of industrial 

 development. The city of Philadelphia slowly pushed out its 

 boundaries, constantly encroaching on the adjacent marshes, and 

 undertook the maintenance of the old dikes and tide-gates within 

 the city limits. Old industries expanded, new industries were at- 



