ENGINEERING. 



345 



quay, which is 18 metres broad. Tho port 

 of HonK-aux has been very deficient in dock 

 fjirilities, vessels having to wait sometimes a 

 month lu-t'or.' they could oome alongside the 

 quays. The port has only been able to accom- 

 modate 200 vessels. Along the docks which 

 are to be made around the new basin 80 ships 

 of tho largest tonnage can lie at the same time. 

 Another basin has been made alongside it for 

 the repairing of men-of-war. 



Extensive improvements are in progress in 

 the harbor at Antwerp, under the joint au- 

 spices of the Belgian Government and the mu- 

 nicipality of the city, designed to unite the pur- 

 poses of extending the harbor and of obviating 

 the floods which sometimes sweep through tho 

 streets of the town. The works, costing accord- 

 ing to the estimates $7,655,000, embrace the 

 straightening of the bank of the Scheldt, tho 

 deepening of its channel by dredging, and tho 

 building of a quay wall of brick faced with 

 stone 47 feet high, 19-6 feet thick at the top, 

 and 28 feet thick at the foundation, and tho 

 construction of three basins with locks con- 

 necting them, one 874 by 197 feet, and the 

 others 806 and 738 feet respectively in length 

 and 164 feet in width. 



For the projected American isthmus canal, 

 see INTEROOEANIO CANAL. A plan for a ship- 

 railway across the Isthmus of Panama attracts 

 much attention. Captain Eads, who has made 

 a thorough study of the possibilities and diffi- 

 culties of this plan of transportation, has elab- 

 orated designs for its construction, according 

 to which it would cost about $50,000,000, or 

 not more than one third of the lowest estimate 

 for a canal. It holds out the promise not only 

 of a perfectly practicable, safe, and economical 

 method of transportation, but also of a very 

 profitable financial investment, which can not 

 be said of any of the proposed canals in the 

 present state of commerce. The railway would 

 have a road-bed not over 40 feet wide, and 8 or 

 10 rails for the car to run on. This would be 

 composed of several separate sections, each 

 about 100 feet long and running on some 200 

 wheels, some of them driving-wheels propelled 

 by an engine attached to the outside of the 

 section. The number of these sections (every 

 one of which constitutes a locomotive) to be 

 joined together in making up the car would 

 vary according to the length of the ship. Rub- 

 ber or steel springs should be placed between 

 the wheels and the frame of these sections. 

 Drawn by five such locomotives, a vescel and 

 cargo weighing 10,000 tons could be transport- 

 ed without giving a pressure on the track under 

 each wheel of more than 12 tons, or a pressure 

 on the road-bed to exceed 1,200 Ibs. per square 

 foot; this is about double the pressure under 

 the driving-wheels of an ordinary goods lo- 

 comotive, and not one half the pressure on 

 the ground under ordinary railroad-ties. The 

 grades would be even and moderate. It would 

 be possible to haul vessels over such a railway 

 at a speed of fifteen or twenty miles an hour, 



or at tho same rate of speed as is ran by freight 

 trains over ordinary railways; although it ia 

 not proposed to run at a greater speed than 

 eight miles an hour. The cost of transporta- 

 tion would probably bo less for the same ton- 

 nage of freight than on an ordinary railway, 

 since all the operations would bo performed 

 by machinery. The transfer of the ships from 

 the sea to the cradle could be accomplished in 

 two different ways : the platform holding tho 

 cradle might be lowered to receive the vessel 

 by means of a lock or by the aid of hydraulic 

 engines. The lock should be in two compart- 

 ments, a deep one with sea-gates, into which 

 the ship would be floated, and in which after 

 the gates are closed it would be raised by the 

 admission of water to the level of the upper 

 lift, in which it would be floated upon the car. 

 After tho ship rests firmly on the cradle in tho 

 upper compartment, which is to be on the level 

 of the railroad track and connected with it by 

 a gate, the water is to bo drawn off and tho 

 gate opened, leaving the car and its burden 

 high and dry on the continuous track. By 

 the other proposed method an iron frame of 

 great strength and solidity, containing the car 

 and a portion of the track, would be lowered 

 in the basin far enough to allow the ship to be 

 floated into the cradle, and then raised by 

 means of hydrostatic cylinders until tho track 

 on this platform meets the main track. 



The reward offered by the State of New 

 York in 1871 for an economical method of 

 propelling boats on the Erie Canal has not 

 been the means of evoking the new system 

 which it was hoped might be developed by the 

 active brains of American inventors, although 

 a good number of novel schemes of more or 

 less merit have been offered for consideration. 

 The five thousand or more boats which navi- 

 gate the artificial waterways of the State are 

 still propelled for tho greater part by animals, 

 and the rest of them by objectionable methods 

 of steam propulsion. The problem seems now 

 to have found its best solution in the adoption 

 of the Belgian system of towing. The New 

 York Steam Cable-Towing Company have ob- 

 tained the exclusive privilege for fifty years of 

 laying a cable for this purpose in the Erie 

 Canal, and have been engaged in propelling 

 boats by this means between Buffalo and Lock- 

 port. They have now extended their cables as 

 far as Rochester, and will probably before long 

 have them working over the whole extent of 

 the canal, from Buffalo to Albany. This sys- 

 tem of towage is not new, having been in use 

 in Europe for eighteen or twenty years ; but 

 the substitution of the lighter and cheaper 

 steel ropes for the ponderous iron chains, and 

 the use of a clip-drum or driving-wheel instead 

 of the indented windlass, are great advance- 

 ments in respect to economy and expedition. 

 Two cables, made of steel wire with a hemp 

 core, are laid in the bed of the canal on different 

 sides. One is used for towing the boats down 

 the canal and tho other the boats going in the 



