New-York tribune. [volume] (New York [N.Y.]) 1866-1924, 1898-03-06


then turned out and also shrurken on the core,
so that when the piece is finished there are two
thic1nesses about one-th.rd Of The way back
from the 'rnuzzle; three thckncsSes from there
to the middle point Of the gun. and four thick
nesses at the point where there will be the
greatest strain over the powder chamber.
Then the gun Is finished externally. rincd ard
provided with brccchloadng mechanism.
PUTTING ON THE JACKET.
But the processes by which the progress Is
made is more complicated than most people
imagine. and without the pondcrous machinery
would be an impossibility. When the tube has
been made ready to receive the Jacket 1t is
placed vertically in a pit SIXTY feet deep and
twenty by forty feet its sides. At one
side of the pit is furnace into which the jacket
is placed to be heated These ponderous masses
of metal arc picked up and placed in position in
the pit by steam and electric cranes which are
capable of lifting from 80 to 10 tons. one Of
these cranes comes along. picks up a piece Of
steel Weighing twenty tons more. walks away
with it and deposits the piece in the pit or at
any other place, without noise or connection.
and apparently without human aid. Jacket
for a lO-inch gun remains in the furnace about
forty Eight hours. The fire never touches the
metal although it surrounds the metallic ir"hox
in which the jacket is heated until it reaches
temperature of about 700 degrees Fahrenheit.
Then the lid is raised from the pit and the piece
is more Grapplcd by the crane, lifted from
the pit and dropped over the upright tube which
stands near by ready to receive its glowing en-
brace.
When the jacket mas been placed in position
over the tube a spray o; water is applied 10 Tie
bottom, where the Joint is 20 be made. This
spray from metal piece which 70
scmbles a heavy hoop. The jets Of water strike
on every point Of the circumference. and the
loop with its hundreds OF cooling sprays IS
gradually drawn up until it has cooled the
whole mass and made the core and the jacket
che piece.
The cranes are again brought into re1uisitiOn.
They pick up the tube enlarged in circumference
and weight by the jacket. from the pit ana
carry il to the lathe where it is prepared To re-
ceive the various pondcrous hoops with which
the building-up process is finished When The
gun has been finished as far as the assembling
of the various tubes is concerned the final fin
ishng is done the lathes.
INFINITELY ACCURATE FINISHING
The finishing Of the inner surface is accom-
plished with such accuracy that Il variation Of
on the part Of the workman who has it in
charge But even with the inner surface fin
ished the gun must still undergo an important
operation which is performed by the aid Of
great grooved drills. After they have cut spiral
grooves into the gun for its whole length-which
process is called rinng-the heavy breech-oac-
ing mechanism is inserted ana the gun is ready
to he taken to Sandy Hook. where its stability
is tested
A Pinch gun. finished all but the loading
mechanism lies at one end of the gun shop. 1t
is 81 feet long weighs 10000 pounds and when
il Is mounted for service will throw proJectlle
weighing thousand pounds many miles. To do
this will require a charge Of five hundred pounds
of powder Thirty-four similar engines Of de-
structon are in course OF construction. and cost.
according to the estimate Of one Of the depart
ment heads about $4,000 each.
The great shop. despite It's monster machines
| is scrupulously neat. Each big machine is in
charge of a skilled mechanic with a helper
whose business 1t is also to keep the place
around the machine in order. They attend to
that part Of their duty faithfully that at the
busy time OF the day it is hard to find scrap
or spot on the wc-kept floor. Great quantities
Of oil are used on the machines. In some in
stances a steady stream of the ubricating ma
terial is kept running over machine. All TINS
oil is used over again and little is lost beyon
what adheres TO the scrap.
In the large gun shop is a monster scale ON
which the guns are weighed in their various
| sbanes This piece OF mechanism is ponderous
| in keepng with it's surroundings and weights ac-
! curately from A fraction of pound to 3WJoOO
| pounds.
MAKING SMALL GUNS.