Proceedings of the P olytechkic Association. 963 



estimated the flow age of a single tide, between IS'ew York and the 

 Jersey shores, at 327,000,000 of tons in weiglit. Assnming that 

 this- is on a full tide of six hours, and that, during the year, at least 

 one-quarter of it is carried around the Battery to the East river and 

 into the sound, we find that there is tlius lost from our ocean chan- 

 nel, the weight and momentum of about 82,000,000 of tons of water, 

 twice in each clay^ on an average, during the whole year round ; and 

 all this, if of the best flowing water for scouring purposes, and such 

 as can be made to go outward to the sea, causing a far greater out- 

 loard flowage than can be brought in by the flood tides. 



If it is asked why not let this condition of things go on, and finally 

 make the Hellgate passage the main eliannel to the city, as it might 

 be made if all obstructions are cleared away ; the reply is that our 

 commerce does not all come from the east, and other great and 

 important interests of the country at large would greatly sufler ; and 

 besides, an insurmountable objection is found in the well known fact 

 that Long Island sound, between Riker's island and Sand's point, 

 freezes up in severe winters, for weeks and even months at a time. 

 Some gentlemen say that the ice from the North river flows into the 

 sound, and spreads out beyond Throg's ISTeck in broken pieces, but 

 quite thick, and in considerable quantities, and that the winds and 

 incoming tides from the sound then bring it back to the narrow 

 channel at Fort Schuyler or Throg's Keck, where it is joined together, 

 and chokes up the passage, and the cold weather soon freezes it all 

 into one solid mass ; thus putting an end to navigation until warm 

 weather again throws it open. This being so, if we keep the North 

 river ice entirely away from the East river, we shall greatly benefit 

 even the sound navigation, besides that of the entire East river up 

 to our city. * 



Having discovered that so large a portion of the Hudson river 

 flowage is lost to the Sandy Hook channel, that it is very largely the 

 cause of the dangerous navigation at Hellgate, and that it fills the 

 East river with ice in winter, and ' possibly aids in the freezing of 

 Long Island sound near Fort Schuyler, we have suggested that a 

 remedy lies in the use of a dyke or dykes across the East river. The 

 proposed dock plan, having several dykes or causeways, is intended 

 to correct the water flowages, and at tlie same time to keep up the 

 passage of vessels through the East river ; and also furnish greatly 

 increased accommodations for our shipping, and all classes of ®ur 

 people ; and thus give a new impulse, in an onward course, such as 



