MECHANICS AND USEFUL ARTS. 51 



over pulleys at the top and bottom of the shaft. The balance 

 weight works also in a pair of guide-rods. Mr. Barlow has de- 

 signed a brake attached to the roof of the lift, and acted on by a 

 powerful double-handed screw on the inside of the roof. The 

 effect of applying the brake is to release 2 arms which clip the 

 guiding-rods on each side, and effectually stop the descent in a 

 few feet. At the bottom of the shafts, and under the level of the 

 subway, are engine-rooms and coke-cellars. The engines at each 

 end are of 4 horse-power, and these will at any time supply more 

 than sufficient power for all purposes. The lifts are adjusted at 

 each end with their doorways inwards towards the subway. On 

 emerging at the bottom of the shafts, the passengers enter a 

 chamber, which constitutes the " station," at and from which the 

 one omnibus, which constitutes the entire "rolling stock " in use 

 at one time, arrives and departs. There is space in these wait- 

 ing-rooms for a seat along each side. We found the workmen at 

 the Tower Hill shaft busy with the fittings and finishings of this 

 chamber, and passing thence we entered the subway and pro- 

 ceeded through its entire length under excellent guidance. 

 Ordinary passengers, when the tunnel has been opened for traffic, 

 will not realize the curious sensation and experience of a passen- 

 ger through on foot, from the noises overhead, on and near the 

 river, so distinctly heard in the subway, which is air-tight as well 

 as water-tight. Arrived at the Tooley Street end, we found the 

 waiting-room occupied by the light iron omnibus in which pas- 

 sengers are to be conveyed. The vehicle, seated for 14 passen- 

 gers, is tolerably roomy as regards width, but is necessarily 

 rather low in the roof. The seats, cushioned and with stuffed 

 backs, are placed lengthways, the entrances being at the ends. 

 The wheels are 16 inches 1 diameter, and at each end of the car- 

 riage a powerful lever brake is fitted, to be worked by the con- 

 ductor with his foot. The service will of course be of the shuttle 

 character, the 2 halves of the omnibus being duplicates, the front 

 end of the vehicle in one journey being the hinder end in the 

 return. The gauge of the rails is 2 feet 6 inches, and the descent 

 from each end to the centre of the subway is by a gradient of 1 in 

 30. We found the works connected with the Tooley Street shaft 

 rapidly approaching completion, but not quite so near it as those 

 at the north end : the' subway itself may be pronounced finished, 

 and the omnibus fit to take the road at any moment. 



The omnibus will be hauled by a wire rope running upon a 

 horizontal pulley-wheel fitted between the rails at one end, and 

 passing round a vertical pulley-wheel at the other. 



THE KANSAS AND MISSOURI BRIDGE. 



This bridge was designed and located by Mr. W. W. Wright, 

 Engineer in Chief, and is being constructed under his supervis- 

 ion. The superstructure is to be of wrought iron, resting upon 

 cast-iron piers, formed of large pneumatic piles sunk to a bear- 

 ing on solid rock. These piles are 8k feet outside diameter, with 



