A little to the south of the entrance to the Commanding Officer's house, stands a large edifice, called the New Arsenal. It is the building with the large square tower—seen in the view in the middle distance, and near the centre of the picture. This building is used for the storage of the muskets during the interval that elapses from the finishing of them to the time when they are sent away to the various permanent arsenals established by government in different parts of the country, or issued to the troops. Besides this new edifice there are two or three other buildings which are used for the storage of finished muskets, called the Old Arsenals. They stand in a line on the south side of the square, and may be seen on the left hand, in the view. These buildings, all together, will contain about five hundred thousand muskets. The New Arsenal, alone, is intended to contain three hundred thousand.
THE WATER SHOPS.
THE MIDDLE WATER SHOPS.
Such is the general arrangement of the Arsenal buildings, "on the hill." But it is only the lighter work that is done here. The heavy operations, such as rolling, welding, grinding, &c., are all performed by water-power. The stream which the Ordnance Department of the United States has pressed into its service to do this work, is a rivulet that meanders through a winding and romantic valley, about half a mile south of the town. On this stream are three falls, situated at a distance perhaps of half a mile from each other. At each of these falls there is a dam, a bridge, and a group of shops. They are called respectively the Upper, Middle, and Lower Water Shops. The valley in which these establishments are situated is extremely verdant and beautiful. The banks of the stream are adorned sometimes with green, grassy slopes, and sometimes with masses of shrubbery and foliage, descending to the water. The road winds gracefully from one point of view to another, opening at every turn some new and attractive prospect. The shops and all the hydraulic works are very neatly and very substantially constructed, and are kept in the most perfect order: so that the scene, as it presents itself to the party of visitors, as they ride slowly up or down the road in their carriage, or saunter along upon the banks of the stream on foot, forms a very attractive picture.
THE MUSKET BARREL.
The fundamental, and altogether the most important operation in the manufacture of the musket, is the formation of the barrel; for it is obvious, that on the strength and perfection of the barrel, the whole value and efficiency of the weapon when completed depends. One would suppose, that the fabrication of so simple a thing as a plain and smooth hollow tube of iron, would be a very easy process; but the fact is, that so numerous are the obstacles and difficulties that are in the way, and so various are the faults, latent and open, into which the workman may allow his work to run, that the forming of the barrel is not only the most important, but by far the most difficult of the operations at the Armory—one which requires the most constant vigilance and attention on the part of the workman, during the process of fabrication, and the application of multiplied tests to prove the accuracy and correctness of the work at every step of the progress of it, from beginning to end.
The barrels are made from plates of iron, of suitable form and size, called scalps or barrel plates. These scalps are a little more than two feet long, and about three inches wide. The barrel when completed, is about three feet six inches long, the additional length being gained by the elongating of the scalp under the hammer during the process of welding. The scalps are heated, and then rolled up over an iron rod, and the edges being lapped are welded together, so as to form a tube of the requisite dimensions—the solid rod serving to preserve the cavity within of the proper form. This welding of the barrels is performed at a building among the Middle Water Shops. A range of tilt hammers extend up and down the room, with forges in the centre of the room, one opposite to each hammer, for heating the iron. The tilt hammers are driven by immense water-wheels, placed beneath the building—there being an arrangement of machinery by which each hammer may be connected with its moving power, or disconnected from it, at any moment, at the pleasure of the workman. Underneath the hammer is an anvil. This anvil contains a die, the upper surface of which, as well as the under surface of a similar die inserted in the hammer, is formed with a semi-cylindrical groove, so that when the two surfaces come together a complete cylindrical cavity is formed, which is of the proper size to receive the barrel that is to be forged. The workman heats a small portion of his work in his forge, and then standing directly before the hammer, he places the barrel in its bed upon the anvil, and sets his hammer in motion, turning the barrel round and round continually under the blows. Only a small portion of the seam is closed at one heat, eleven heats being required to complete the work. To effect by this operation a perfect junction of the iron, in the overlapping portions, so that the substance of iron shall be continuous and homogeneous throughout, the same at the junction as in every other part, without any, the least, flaw, or seam, or crevice, open or concealed, requires not only great experience and skill, but also most unremitting and constant attention during the performance of the work. Should there be any such flaw, however deeply it may be concealed, and however completely all indications of it may be smoothed over and covered up by a superficial finishing, it is sure to be exposed at last, to the mortification and loss of the workman, in the form of a great gaping rent, which is brought out from it under the inexorable severity of the test to which the work has finally to be subjected.