42 ANNUAL OP SCIENTIFIC DISCOVERY. 



present commissioners. During the year ending November 1, 

 1867, 1,043 feet heading has been made, at the rate of 71 feet a 

 month up to last July, and at a rate of 119 feet a month since that 

 time ; thus making the east end heading 4,474 feet in extent. 



The central shaft from the summit of the mountain to the line 

 of grade is to be 1,030 feet in depth. Its size is 27 feet by 15, and 

 is of an oval shape. Up to November 1, 1866, this shaft had been 

 sunk 354 feet, of which distance 153 feet was in the previous year. 

 During this time work was suspended for three months on account 

 of necessary work upon machinery. From November 1, 1866, to 

 October 19. 1867, the date of the sad accident which has cast a 

 temporary gloom over the enterprise, this shaft has been sunk 227 

 feet, making the present depth 581 feet. The west shaft is 316 

 feet deep, is sunk to grade, and is being satisfactorily worked 

 on both faces. At the west end of the tunnel, the distance from 

 the west shaft to the instrumental pier, which stands at or near 

 the west portal of the tunnel, is 2,447 feet. It can thus be seen 

 that 6,791 feet of progress on the tunnel have actually been made, 

 besides considerable other work which might properly be reck- 

 oned. 



TUNNEL FROM NEW YORK TO BROOKLYN. 



Since last winter, when, on account of floating or fixed ice, 

 communication between New York and Brooklyn or Williams- 

 burgh was either cut off for hours or rendered insecure and pre- 

 carious for days, there has been a desire that some more certain 

 if not more rapid means of intercommunication should be con- 

 trived. A charter for a bridge company \vas secured at the last 

 legislative session, and preliminary surveys are now in progress 

 on both sides of the estuary known as East River. The bridge to 

 be constructed will probably be a suspension bridge, with one or 

 two stories, and of a length between points of suspension exceed- 

 ing that of any other on the continent. But vast as is this under- 

 taking, the approaches to the bridge proper are hardly less in 

 magnitude. 



As long ago as 157 we published (vide " Scientific American," 

 Vol. xii., No. 30) a plan proposed by Mr. Joseph De Sendzimir, 

 by which a passage across the East River could be secured with- 

 out a structure exposed to gales, and without approaches entailing 

 travel of three times the width of the 1 strait. It was, in brief, 

 similar to that now in progress across the Thames at London for 

 the Pneumatic Despatch. It was a submerged tube of iron sunk 

 in the bed of the river, the central portion level and the remainder 

 rising gradually to either shore. In order to diminish the grade, 

 the tube, on the Brooklyn side, where the natural descent is 

 greater than on the other side, makes a curve or bend. The 

 deepest portion of the river-bed is only 47 feet below the surface 

 at IOAV water, and the tube may be "either supported on piles 

 driven into the bed of the river oHie upon a bed scooped for it so 

 that the top may reach only to the surface of the bed. That this 

 plan is feasible cannot be successfully denied; that it will offer 



