976 Transactions of whe American Institute. 



that any Increase of such power would tend at once toward an 

 improvement. 



If tlien, we examine the present tidal action in the a arbor, we 

 find that it is entirely witliout a parallel in other localities, and are 

 able to apprehend one radical source of the loss of power in its 

 important ebb flow, and the simple remedy. 



New York harbor, by the channel of the East river, has a direct 

 tidal connection with Long Island sound, in a distance of about 

 sixteen and one-half miles. This river differs entirely from the 

 Passaic, Ilackensack, and Hudson rivers, which bring a large supply 

 of fresh water into the harbor, not being in any sense an affluent or 

 feeder, but simply a tidal channel. 



Now it apjDears, from a little study of the ordinary daily naviga- 

 tion of this channel, that except for powerful steamers, it is restricted 

 to tlie times of favorable tidal currents, for vessels passing between 

 the harbor and the sound. About the time of slack low water at 

 Governor's Island, it will be observed from the swing of anchored 

 vessels, that while the Hudson is running down witli a strong .ebb, 

 between Castle Garden and Castle William, there is an eddy toward 

 tlie East river, while vessels lying opposite tlie Brooklyn south 

 ferry house are swinging around, showing a cessation of the East 

 river ebb, at Buttermilk channel sometimebeforetliat of the Hudson. 



Consequently, tlie rule for vessels going into tlie sound is <to come 

 down the Hudson on its ebb, so as to take tlie first of tlie East river 

 flood and carry it into the sound ; vessels at Throg's Neck take the 

 East river ebb to Governor's Island. Pilots assert th-at the first of 

 the flood can be taken at the Battery and carried about thirty miles 

 into tlie sound ; it is also an annual winter experience' that ice carried 

 through Ilellgate and Throg's Neck, from the harbor, sometimes 

 obstructs the entrance to Throg's Neck, for several days, for westward 

 bound vessels. 



The distance from Sandy Hook to Throg's Neck, is about thirty- 

 four and one-half miles, the center of the sound, opposite Bridgeport, 

 being midway between Sandy Hook and Montauk Point, or about 

 seventy-four miles from either. 



A reference to the tide tables and charts of the coast survey, 

 shows that the crest of the ocean tidal wave, which enters the Atlan- 

 tic from, its commencement near Australia, strikes Sandy Hook about 

 an hour before Montauk Point. The velocity of the wave of oscilla- 

 tion from Sandy Hook to Governor* Island is 20,34 miles per hour 



