3S4 ANNUAL RECORD OF SCIENCE AND INDUSTRY. 



feet wide, and in no part less than twenty feet deep, with the 

 central part thirty feet deep, where but fourteen to fifteen 

 feet had previously existed ; that the temporary deposit 

 which had formed in the Pass and between the jetties dur- 

 ing the time in which a portion of the flow into the Pass 

 had been interrupted by the work at its head has, since the 

 restoration of the normal flow through the new channel at its 

 head, by its removal caused the Pass to enlarge again ; an ac- 

 tion that has, since this restored flow began, removed from 

 between the jetties in the last three months over half a mill- 

 ion cubic yards of deposit, and established through more 

 than half the length of the jetties a much larger and deeper 

 channel than had ever previously existed, the size of which is 

 already, throughout more than two thousand feet, twenty- 

 eight feet deep by three hundred feet wide, while for many 

 hundreds of feet it exceeds thirty feet deep by three hundred 

 and fifty feet wide; and, finally, the report affirms what is of 

 the last importance to the permanent success of the work 

 that the gulf current athwart the jettied mouth of the Pass 

 effectually prevents the re-formation of the bar in advance 

 of the jetties by deepening the outer slope of the bar, and 

 sweeping away any such portion of the discharged sedi- 

 ment as the river current fails to carry to unknown dis- 

 tances seaward. 



The fact is worthy of mention, finally, that on the 1st of 

 November, 1877, the steamship City of Bristol, of the well- 

 known Inman line, passed through the jetties without de- 

 tention and without touching. Her draught was twenty- 

 one feet eight inches, and the tide at the time was two 

 and a half inches below " average flood-tide," which is the 

 plane of reference established by the United States engi- 

 neers. 



OTHER AMERICAN ENGINEERING WORKS. 



Concerning the East River Bridge, the Hudson River Tun- 

 nel, the New York elevated railroads, and the Poughkeep- 

 sie Bridge (which are probably the most noteworthy domes- 

 tic engineering works in course of construction), we have 

 nothing especially noteworthy to record, save that all are 

 making gradual progress towards completion. 



