MECHANICS AND USEFUL ARTS. 121 



at a cost of 3,500,000 dollars per mile, the bulk of which has been 

 applied towards compensation for damages. The length of the new 

 line is nearly 3 miles, and has 6 stations, — one at Westminster 

 Bridge ; one in the Broadway, at St. James's Park ; one at Vic- 

 toria, where it joins the Chatham and Dover line ; one at Chelsea, 

 nearSloane Square ; one at South Kensington ; and one in the Glou- 

 cester Road, West Brompton. Of the whole length of line about 

 one-third is tunnel and the rest open cutting. 



No very special engineering difficulties were met with in the 

 construction of the line, except the continued presence of water, as 

 some parts of the works are below low-water mark. The great- 

 est depth below the surface to the rails is not more than 32 feet, 

 the quickest curve is 440 feet radius, and the greatest incline one in 

 250 feet. Considerable difficulty was experienced during the 

 construction of the line, from water, both from the sewers and 

 from the surface drainage. On one very wet day in the early 

 summer no less than 6 sewers burst at once, and gave the 

 pumps enough to do to keep their contents, with the surface drain- 

 age, from flooding all that was then built of the line. To this 

 diiy, and as long as the line is in use, there must always be per- 

 manent pum})ing-stations for the more surface drainage, there 

 being no outlet toward the river without raisin <2r it to a hifrher 

 level. This water difficulty, however, is very ingeniously met 

 by Messrs. Fowler and Johnstone, the engineers of the line. The 

 side walls, both of the arched tunnels and open cuttings, are made 

 of extra thickness, and, above ali, are connected beneath the 

 ground by an inverted arch of concrete nearly 3 feet thick. This 

 effectually prevents the water rising up through the floor of the 

 line, and equally prevents the surface water from draining off. 

 For this surface drainage, the refore, special provision is made, by 

 mtnins of pipes laid in the centre of the line, which carry the water 

 on to tiie pumping-stations, where it is raised and sent away 

 into the Thames. Passing under the middle of the Broadwa}^ the 

 line is carried, not in a tunnel, but in a broad, lofty, square cham- 

 ber, with a flat roof, on massive wrought-iron girders. This is a 

 beautiful piece of work, both in its design and finish, and is of the 

 most unexceptionable character from beginning to end. While 

 passing along the Broadway special preeauiions were taken to 

 guard against any possible vibration afiecting Westminster Abbey, 

 The walls on the Abbey side are here made 7 bricks thick. Be- 

 hind this comes the Victoria sewer in a tube of iron, and behind 

 all a bed of peat 7 feet thick. The peat cliecks all vibration, but 

 as the nearest point at which the line passes is more than 90 feet 

 from the Abbey walls, its deadening properties are scarcely re- 

 quired. 



After Westminster Bridge the first station is St. James's Park, 

 and leaving this the line continues in an open cutting to Bucking- 

 ham Row, where it enters a tunnel of about 500 yards in length. 

 Here the water occasioned so much difficulty that engines had to 

 be kept going night and day, pumping at the rate of nearly 4,000 

 gallons a minute. The tunnel at this point passes but a few feet 

 below the surface of the ground, yet it forms the foundation of 



11 



