I. PASSENGER AND FREIGHT ELEVATORS. STEAM ELEYATORS.—A simple form of steam freight elevator, manufactured by Otis Brothers & Co., of New York, is represented in Fig. 1. It is particularly adapted to buildings where high-pressure steam is available. and is intended for handling heavy freight. W is the steam hoisting-engine, B the elevator platform. 0 the overhead sheave, and_Li the pipes leading steam from boiler to engine. The arrangement of the vertical inverted engines and hoisting-di-inn of this elevator is shown in Fig. 2.
The Belt Elevator System is represented in Fig. 3. A is the elevator, B the platform, E the motor-engine, and (.; the overhead sheave.
Elevating Deck Ferry-Boat.—Figs. 4 and 5 illustrate a novel ferry-boat of English con struction, in which the entire deck is elevated. The deck is actuated by hovel and worm gearing, so that at any state of the tide it may be brought to the same level as the quay for tile shipment of vehicles, etc. The elevating deck is 78 ft. long and 32 ft. broad. The cle vator apparatus is worked 1w triple-expansion engines, which actuate shafting geared to each of the vertical screws. The lift is 14 ft. (Sec Engineering, Sept. 3, 1890.) II. ItYDRAULIC ELEvAToRs.—Figs. 6. 7, and e represent the principal types of these maehims as made by Otis Brothers & Co. Fig. 6 shows the street-pressure system adapted to cities where there is a steatly water-pressure in the mains. A is the hydraulic cylinder, B the elevator-car, C' the overhead sheave, and I) the con trolling rope. The arrangement of water supply and waste-pipe will readily be un derstood. For use in cities where there is no public water-supplv under pressure, the apparatus representea in Figs. 7 and 8 are provided, in Fig. 7 known as the pressure tank-in-basement system. A is the hy draulic cylinder, B the ear. C the over head sheave. D the controlling rope, L' pump (steam or gas), a tank in the basement to receive the discharged water from the cylinder, G an iron pressure tank, If the supply-pipe to the cylinder through the valve, I the water-pipe from the pump which tills the pressure-tank, ii the cylinder discharge-pipe. and L the steam-pipes leading from pump to boiler.
Fig. S shows a combined gravity and pressure-tank-on-roof system, which dif fers from that last described in the arrange ment of the tank 0 on the roof instead of in the basement, and the consequent utili zation of the gravity of the descending water.
The latest form of Otis hydraulic eleva tor is illustrated in Fig. 9. The principal novel features here are the pilot-valve and the port-stop. A lever in the car is con nected by a suitable device with the valve sheave, so that a movement of the lever gives a corresponding movement of the sheave, and through it to the pilot-valve. The valve operates in the following manner: The area of the upper piston is twice that of the lower piston ; therefore, when the small pilot-valve is raised by the lever (thusopening communication be tween the upper part of the large valve-cylinder and the tank) the main valve will move up : but the moment the valve begins to move. it commences to close the pilot-valve port, thus cutting off the discharge at a point proportionate to the move ment of the lever in the car. By lowering the pilot-valve, water is admitted to the upper part of the large cylinder, and the valve descends in the same manner as above. The port or apron stop consists of aprons on top and bottom of piston, with holes drilled in them in a progression such that when the apron ad , vamps over the upper or the lower port the area for the out flow of water is gradually di ' in in ished. in a ratio such that the retardation of the piston is uni form thnmghout the length of stop, therefore bringing the car to a gradual stop.
The ligarnulie Elevators in the Eiffel 'Tower. —The EWA Tower is erected on the Champs-de-Mars, Paris. and originally formed one of the buildings of the French Exposition of 1889. It consists essentially of a pyramid composed of four great curved columns in dependent of one another, and connected only by belts of girders at the different sto ries until they unite toward the top of the structure, where they are joined by ordina ry bracing. The material used in the con struction is iron. The principal data con cerning this building—at the time of its erection the most lofty in the world—are as follows : Total height, 084 ft. ; weight of iron used, 7,300 tons ; number of pieces of iron of different forms employed, about 14,000; total thrust on foundations, 565 tons--or, under maximum wind-pressure, 875 tons.