_On Making Gun-Barrels._—The selected scraps to be worked into gun-barrel material are cut into small pieces and thrown into a furnace, where they are exposed to intense heat until fused, after which they are brought forth an adhering mass and placed under a hammer, which drives them together and forges them into bars. The bars are next rolled into thin plates, and then cut into strips twelve inches long and six inches wide. The _very best_ guns are made of a combination of iron and steel. Both materials having been rolled and cut into sheets of exactly the same size, these sheets (one-fourth of an inch thick) are piled upon each other alternately to the number of thirty, and subjected to a welding heat; they are then driven together under a five-ton hammer into a consolidated slab. The slabs so formed are next worked down into one-fourth inch square rods. The more the material is hammered and worked the better it is. The rods are next twisted until they present the appearance of a strand of rope, some rods being twisted to the right and others to the left. Two rods, with opposite twist, are heated to the welding degree, placed upon each other, and rolled together; they are now in a narrow slab, presenting that fine curl of “grain” peculiar to the Damascus, or that beautiful wavy figure peculiar to the laminated steel, as the case may be. The next operation is to coil one of these slabs around a mandrel in a spiral form, and weld it securely under the blows of hand-hammers. It is now a gun-barrel in the rough. _Finishing and Proving._—The rough barrel goes from the welder to the borer, where it is put through the process of “rough boring.” From the “rough borer” it goes into the hands of the “fine borer,” who bores it out smoothly and to near the size it is to be when finished. Another operator then takes it in charge and dresses it to smoothness externally, then the “tester” takes it and dips it into strong acid, which soon shows any imperfection in either twist or welding that might exist. If not perfect, it is sent back to be worked over; if all right, it passes to the next department, where it is straightened inside. This part of the work is governed entirely by the eye, and hence demands the services of a workman of great skill, and experience. Having been “passed on” by the “straightener,” the barrel goes to the “turner,” who turns it in a lathe until the outside is true and correspondingly straight with the interior, and is of exactly the required weight. If the arm is to be a double-barrel shot gun, the barrel next goes into the hands of a workman who joins it to another barrel with the utmost nicety; to attain which, levels and other suitable instruments are brought into requisition. Like the man who straightens the bore, the man who joins the barrels must be a workman of great skill.