302 



ENGINEERING. 



the " Bergen," as the new boat is named, would 

 have many advantages over side- wheelers for 

 war service, since her screws and the most 

 vulnerable parts of her machinery are under 

 water. The "Bergen's" builders are Thomas 

 C. Marvel & Sons, of Newburg, N. Y. 



Ferry at Greenwich, England. More than two 

 centuries and a half have passed since a ferry 

 was first established at Greenwich, on the 

 Thames, below London, but no attempt has 

 been made until the present year to introduce 

 modern methods. The peculiar difficulties of 

 the situation include a sloping river- bottom 

 and a tidal rise and fall of 20 feet. At high 

 water, therefore, the boat can land at the bulk- 

 head line, but at low tide she can not approach 

 it within three or four times lier length. To 

 overcome this, an inclined railway, 348 feet 

 long, has been laid on the bottom, the whole 

 securely bedded in concrete. Up and down 

 this incline a landing-stage is moved by means 

 of suitable machinery, and two platforms are 

 made to travel back and forth between the 

 landward side of the stage and the wharf, what- 

 ever the distance may be. k ' On each side of 

 the river," says London " Engineering," in a 

 detailed description of this ferry, u close behind 

 the abutment, two cast-iron cylinders are sunk 

 close to each other to a depth of 145 feet below 

 the level of the roadway. The cylinders are 

 10 feet diameter on top, increasing in size by 

 varying cones to 11 feet 6 inches in diameter 

 at the bottom. The metal varies in thickness 

 from |- inch to If inch. The contractor for 

 this work, with fine old English crusted con- 

 servatism, is doing the sinking of the cylinders 

 with divers, so that it is at once evident that 

 speed of sinking and cost are matters of com- 

 paratively small importance. 



" The cylinders are for the purpose of wells, 

 in which weights will be worked to act as 

 counterpoises to the traveling carriages and 

 landing-stage. Sufficient engine -power has 

 been provided to overcome the inertia in mov- 

 ing these platforms, and also any additional 

 weight of traffic which they may carry. As 

 the slope on which they travel is 1 in 10, one 

 tenth of the weight in the wells will balance 

 that of the platforms and landing-stage." 



It seems well nigh incredible that such primi- 

 tive methods of propulsion should be used in 

 the greatest capi'al of the world, and there is 

 no obvious reason why the double-ended Amer- 

 ican ferry-boat system should not have been 

 used to advantage in dredged ferry-slips, in- 

 stead of the comparatively complicated stages 

 and platforms here described. 



Moving the Brighton-Beach Hotel. During the 

 winter of 1887-'8S the ocean made such en- 

 croachments along the beach of Coney Island 

 that the foundations of the Brighton-Beach 

 Hotel were undermined and the entire base- 

 ment story was washed away. The most ap- 

 proved devices were tried in vain to prevent 

 the inroads of the sea, and the hotel proprie- 

 tors finally decided to move the building back 



six hundred feet to a place of safety, a work 

 of no small magnitude, since the building, a 

 wooden structure, was 465 feet long, 150 feet 

 deep, and three stories high. The estimated 

 weight was 5,000 tons. The contract was 

 awarded to B. C. Miller & Son, of Brooklyn, 

 who agreed to do the work for $12,000. 



The first operation was to lay twenty-four 

 parallel tracks underneath the building and 

 extending landward about three hundred feet. 

 A mile and a half of rails and 10,000 ties were- 

 used, the ties resting upon planks. The build- 

 ing was then jacked up, and 112 ordinary plat- 

 form cars, hired for the purpose, were rolled 

 under the building, bavins transverse timbers 

 laid across them for the sills to rest upon. A 

 twenty-foot section of the hotel was raised 

 enough to admit the passage of the cars with 

 an inch or two to spare, and when the car was 

 in place the section was lowered, care being 

 taken to adjust the bearing so as to secure as 

 even a distribution of weight as possible. The 

 cars were jacked apart before the weight was 

 allowed to settle upon them. Heavy tackle- 

 blocks and falls were next attached to the 

 twenty-four lines of cars upon which the bridge 

 finally rested, and the running parts were 

 attached, as shown in the illustration, to loco- 

 motives, some of the falls crossing one another, 

 so that each gang of locomotives had its pull- 

 ing-strain distributed over more than half of 

 the building. 



On April 3 the ropes were tightened for the 

 first time, and the building was moved a short 

 distance without difficulty. The next day, with 

 four locomotives, it was moved to the end of 

 the rails. The track already passed over was 

 then taken up and moved in front of the loco- 

 motives and the rest of the journey completed 

 without the least difficulty. Probably it is the 

 most considerable feat of house-moving ever 

 undertaken. 



Harbor Improvement. Commercially speaking, 

 one of the most important works recently un- 

 dertaken by the United States Government is 

 the deepening of the channel in New York 

 harbor. In view of the greater length and 

 deeper draft of ocean steamers, it has become 

 necessary to deepen the channels, and at the 

 same time to straighten them, because quick 

 turns are impossible for very long ships. Large 

 steamers are obliged to fix their hours of sail- 

 ing so as to reach the bar at high tide, and in- 

 ward bound vessels are frequently obliged to 

 anchor outside and wait for high water. In 

 1884 an appropriation of $200,000 was made 

 by Congress for the improvement of Gedney's 

 channel, and Col. G. L. Gillespie. of the United 

 States Corps of Engineers, was directed to make 

 a survey with a view to determining the best 

 course of procedure. The result of careful 

 soundings showed that no shoaling whatever 

 had taken place since the first accurate coast 

 survey of 1835, a channel twenty-three feet 

 deep having been maintained by the natural 

 scour of the tides. It was held, therefore, that 



