carefulness such as are seldom seen in ordinary workmen. The foreman now
issues the different pieces to the finishers, who convey them to the
annealing room, where they are rendered soft for working by heat, and
cleaned of their scale or oxide, which would otherwise injure the tool, by
means of dilute sulphuric acid.
The barrel is welded and finished in a separate factory. The piece of
metal out of which the gradually tapering tube is ultimately fashioned
seems to bear no relation to such a form. You see the smith take a small
plate of quarter-inch iron, about a foot long by a few inches wide, heat
it to a welding heat, and then place it between the lips of a rolling
mill, with grooved instead of flat rollers, and in an instant it comes out
a tube. It has next to be drawn out to the requisite length and tapered,
which is done by passing it through a series of mills, each succeeding one
being grooved smaller than the preceding. The bore is kept hollow during
the operation by a central iron rod. The breech piece is welded on by a
single blow of a steam-hammer, and the process of turning the bore begins.
Four barrels are acted upon by one lathe, and the first operation is
performed in fifteen minutes. Only a slight cutting is made each time, and
the barrel has to be submitted to the action of many different boring
instruments until the exact size, ·577 of an inch, is attained. The
outside is now turned, the tool taking off the superfluous metal in one
continuous ringlet of iron.
It now undergoes the most delicate process of all, that of being "viewed."
The viewer, who is a highly-skilled workman, with an exceedingly accurate
eye, puts himself opposite a gas-lamp, about thirty feet distance, and
which has a dark shade on its upper side. Towards this object he directs
the barrel so as to bring the dark edge half-way across his sight as he
looks through the bore. By this device he is enabled to direct a ray of
light with a defined edge down the tube, and by turning the barrel round,
instantly detects the slightest deviation from the straight line. As the
smoothest-looking sea is discovered to be a mass of dimpling ripples--(the
Greek poet's "infinite laughings of the sea")--when the setting sun throws
a golden shaft across its bosom, so the mathematically straight lines of
light gauge the inequalities of the rifle bore in a more exact manner than
any instrument that has yet been invented. When any irregularities are
discovered, the viewer taps the barrel with a fine hammer on a small
anvil, and repeats the operation until the tube is perfectly true. Upon
this depends the correct shooting of the gun, inasmuch as the least crook
near the end of the bore would send a bullet far on one side of the mark
long before it had attained the full range of 800 yards, to which the
Enfield rifle is sighted. The rifling of the barrel in three groves is
performed by fixing it in a lathe, and driving the cutter through it in a
spiral direction.
Public-domain text, read in full here on John Shaqi.
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