Having thus given a general description of the exterior of the establishment, let us now enter the works and witness the entire operations of manufacturing the musket, seriatim.

The first operation is the formation of the barrel.  Formerly these were made from plates of iron called scalps, about two feet long and three inches wide, which were heated to a white-heat and then rolled up over an iron rod, and the edges being lapped were 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 was performed by tilt-hammers, which were carried by the water-wheels.  Underneath the hammer was an anvil containing a die, the upper surface of which, as well as the under surface of a similar die inserted in the hammer, formed a semicylindrical groove, producing, when the two surfaces came together, a complete cylindrical cavity of the proper size to receive the barrel to be forged.  The workman, after heating a small portion of the barrel in his forge, placed it in its bed upon the anvil, and set his hammer in motion, turning the barrel round and round continually under the blows.  Only a small portion of the seam is closed by this process at one heat, eleven being required to complete the work.  To effect by this operation a perfect junction of the iron, so that it should be continuous and homogeneous throughout, without the least flaw, seam, or crevice, required unremitting attention, as well as great experience and skill.  The welders formerly received twelve cents for each barrel welded by them, but if, in proving the barrels, any of them burst, through the fault of the welders, they were charged one dollar for each barrel which failed to stand the test.  This method has now, however, been abandoned, and a much more economical and rapid process adopted in its place.  Instead of plates of two feet in length, those of one foot are now used.  These are bent around an iron rod as before; but in place of the anvil and tilt-hammer, they are run through rolling-machines, analogous in some respects to those by which railway-iron is made.  The scalps are first heated, in the blaze of a bituminous coal furnace, to a white-heat,—­to a point just as near the melting as can be attained without actually dropping apart,—­and then passed between three sets of rollers, each of which elongates the barrel, reduces its diameter, and assists in forcing it to assume the proper size and taper.  The metal by this process is firmly compacted, becoming wholly homogeneous through its entire length.

This operation of rolling the barrel is not only a very important and valuable one, but very difficult of acquisition, the knowledge appertaining to its practical working having been wholly confined to one person in this country previously to the breaking out of the Rebellion.  The invention is English, and has been used in this country but a few years.  Only one set of rollers was used at this armory until