Last on the foreign side is the British machinery, and the collection is very much larger and more varied than any of the preceding. There are few lines of manufacture which are not represented here. Machines for working in iron and other metals, for sawing and fashioning wood, for the ginning, breaking or carding of cotton, flax, wool, jute and hemp, for working in stone, glass, leather and paper, are shown. Then, again, the finished productions; prime motors, such as stationary engines, locomotives and fire-engines; lifting-machines for solids or liquids, cranes, jacks, elevators, pumps, each in endless variety.
Prominent in the hall, and employed in driving the machinery, is the large double compound horizontal engine of Galloway of Manchester. This form of engine is coming to the front, as is evinced especially in the marine service. Maudslay & Sons of London exhibit a model of the four-cylinder marine compound engine as fitted on the "White Star line" vessels, the Germanic, Britannic, Oceanic, Baltic and Adriatic, and on the steamers of the "Compagnie Générale Transatlantique," the Ville de Havre, Europe, France, Amérique, Labrador, Canada. The vessels of the New York and Bremen line have the same class of engines, built in Greenock, Scotland.
Amid so large a mass of machinery one can but select the most prominent, and among these we may choose such as, while not necessarily imposing in size, are suggestive of ideas which we may find valuable for home introduction. Appleby & Sons lead the world in the completeness and capacity of their great cranes and lifts for docks and wharves, machine-shops, erection of buildings, and travelling cranes for railways or common roads. We must make one exception--the elevators for hotels and warehouses, in which America is in advance of all other countries. While we have many varieties of these, we must give credit where it is due, and the _ascenseur Edoux_ of Paris is the original of all those in which the cage is placed upon a plunger that descends into a vertical cylinder into which water is forced to elevate the plunger, and from which it is withdrawn to allow the plunger and cage to descend. Very fine specimens of this class of elevator are in the New York Post-office building. The gantry crane of Messrs. Appleby Bros. of London is the most complete engine of its kind in the world. It was originally constructed for the growing requirements of the docks of the North-eastern Railway Company of England at Middlesborough. The term "gantry" is applied to the movable scaffold or frame, which in this case rests upon a pair of rails twenty-three feet apart, one of them being close to the edge of the quay. The clear height is seventeen and a half feet, which allows the uninterrupted passage of locomotives and all kinds of rolling-stock on each of the two lines of rails which are spanned by the gantry. The crane is designed for a working load of five tons, with a maximum radius of twenty-one feet from the centre of the crane-post to the plumb-line of the lifting chain, with a capacity for altering the radius by steam to a minimum of fourteen feet. The crane has capacity to (1) lift and lower; (2) turn round completely in either direction simultaneously with the lifting and lowering; (3) alter the radius by raising or lowering the jib-head; (4) travel along the rails by its own steam-power. All these motions are easily worked by one man, who attends to the boiler. The travelling motion is transmitted from the crane-engines by suitable gear and shafts to the travelling wheels, and warping-drums or capstans are fitted on a countershaft on the inner side of each frame, which drums can be driven independently of the travelling wheels for moving trucks into position below the crane as they are required for loading and unloading. Smaller cranes may pass with their loads below the gantry, and a number of these large cranes may be assembled so as each to work at the different hatchways of a large screw steamer, or two may be associated together for any exceptionally heavy lift. The value of elevation of the crane is not only in allowing the loaded cars to be brought on tracks beneath it, but in giving it capacity to work over the sides of large vessels, which when light may rise twenty feet above the level of the quay, and to load or discharge from trucks on two lines of rails on the land-side of the gantry, overhead of the trucks on the two lines which run below the gantry.[6]