Stepping out of this pandemonium, there are rows upon rows of gleaming forges, each with its appointed smiths, whose hammers rise and fall in rhythmic strokes, and who manufacture the minor portions of the incipient locomotive. Here is a machine the central part of which resembles a great corkscrew or spiral constantly revolving. A weight is affixed to its inclined plane, and is carried up to the required height by the revolution of the screw, to be let fall upon a piece of red-hot iron, which in that moment becomes a bolt, with its projecting head or cap. Though they do not properly belong to our subject, the great marine boilers in course of construction in the adjoining department cannot be overlooked, even if only for their size--vast cylinders of twelve feet diameter. Next comes the erecting shop, where the various parts of the locomotive are fitted together, and it is built up much as a ship from the keel. These semi-completed engines have a singularly helpless look--out of proportion, without limbs, and many mere skeletons. Close by is the department where engines out of repair are made good. Some American engineer started the idea of a railway thirty feet wide, an idea which in this place is partially realized. The engine to be repaired is run on to what may be described as a turn-table resting upon wheels, and this turn-table is bodily rolled along, like a truck, with the engine on it, to the place where tools and cranes and all the necessary gear are ready for the work upon it. Now by a yard, which seems one vast assemblage of wheels of all kinds--big wheels, little wheels, wheels of all sizes, nothing but wheels; past great mounds of iron, shapeless heaps of scrap, and then, perhaps, the most interesting shop of all, though the least capable of description, is entered. It is where the endless pieces of metal of which the locomotive is composed are filed and planed and smoothed into an accurate fit; an immense building, with shafting overhead and shafting below in endless revolution, yielding an incessant hum like the sound of armies of bees--a building which may be said to have a score of aisles, up which one may walk with machinery upon either side. Hundreds of lathes of every conceivable pattern are planing the solid steel and the solid iron as if it were wood, cutting off with each revolution a more or less thick slice of the hard metal, which curls up like a shaving of deal. So delicate is the touch of some of these tools, so good the metal they are employed to cut, that shavings are taken off three or more feet long, curled up like a spiral spring, and which may be wound round the hand like string. The interiors of the cylinders, the bearings, those portions of the engines which slide one upon the other, and require the most accurate fit, are here adjusted by unerring machinery, which turns out the work with an ease and exactness which the hand of man, delicate and wonderful organ as it is, cannot reach.