Proceedings of the Polytechnic Association. 1021 



A gentlemen compared the probable results of damming the East 

 river, with what had evidently occurred in times past in the case of 

 the Harlem river. The channel would be filled up with deposits, 

 and the outlet to tlie ocean be lost. We should not risk the advan- 

 tages which we now possess for the sake of uncertain results of an 

 enterprise like the dam proposed. 



Prof. Yanderwevde explained at length the formation of cur- 

 rents through the East river, from the difference between tlte time 

 of flood tide in tiie Sound and at other points on the shore of Man- 

 hattan Island. 



Dr. Bradley favored a tunnel under the East river. The tunnel 

 should have a level grade, and be reached at either end by elevators 

 worked by steam power. 



Dr. Hallock said that, with reference to the dams or causeways, 

 no matter what the width of the passages left therein, slack water 

 would be caused, and from this at the sides of the channel silt 

 would be gradually deposited, which in the course of time would 

 narrow and destroy the channel. 



Remarks were also made by several others among the crowded 

 audience who attended the meeting. 



Prof. Yanderweyde stated that tlie Xorth river has two outlets 

 to the ocean, that of Sandy Hook and the East river. He was con- 

 vinced that the filling up of th#East river will improve the navigation 

 of Sandy Hook. Twenty-five years ago there was a necessity for 

 making a ship canal at North Holland on account of the river filling 

 up. 



The debate continued to a late hour, and it was evident that the 

 meeting was of opinion that both the State and N^ational Governments 

 should institute a series of examinations and inquiries which would 

 throw some new liglit as to the question whether the East river tide 

 is the cause of the gradually filling up of the bay at Sandy Hook. 



Phenol-Camphok Disinfectant. 

 Mr. O. G. Mason, exhibited a specimen of carbolic acid and 

 camphor combined. The mixture is two ounces of gum camphor 

 and one of carbolic acid in crystals .which makes a liquid ; from this 

 was taken one ounce, and mixed with thirteen ounces of prepared 

 chalk, making about one pound. The object of camplior in this 

 compound is to destroy or neutralize the peculiar smell of carbolic 

 acid wlien usedfor disinfecting and other purposes. 



