Putnam patriot., 1914-09-04
MAKING \ BIC GUN
One of the Amazing COnqueStS of
 Modern Engineering.
WEAPONS WITH SHORT LIVES.

Shell Passage Means Three Seconos-
 In the manufacture of big guns the
 engineer has certainly achieved some
 of his most daring cenGpests, fer it k
 doubtful if there k 4sthing more
 wonderfully fashioned or scientifically
 constructed than the monster weapons
 found on the latest hattieships and in
 large forts.
 From their muzzles they are capable
 of launching into space shells weigh ing as much as half a ton at a speed
 of thirty Live miles minute. or 2.lo0
 miles an hoT. These death dealing
 missiles may be so designed as to
 burst after they have forced their way
 through ships side or immediately
 they strike an object or at some point
 during their flight
 The biz gun itself consists of sev-
 eral tubes, or cylinders, slipped over
 one another and named after the let ters of the alphabet. A is inside
 and seorched by the powder gases.
 '.B' goes over ".N. and so on, the out
 side tube of all being known as the
 jacket
 Each separate tube. or cylinder, is fashioned in much tine same way. In
 the case of the A" tube for a twelve
 inch gun huge solid steel ingot is east. weighing upward of thirty tons.
 The ends having been cut off, the in got is mounted ill a lathe. and tube like "trepannins" borer removes q long core from the center. The iugot iS then dismounted from the lathe and
 heated A long. hollow bar somewhat smaller than the destined bore of the
 gun is passed through the central hole. and the ingot is placed under 2,5oo ton forging press. which gradually shins and draws 1t out along the bar. which is kept cOol ny water circulat- ing through it. After being turned outside and bored inside the tube has to be tempered. and this is done by dipping it into q tank filled with thou sands of gallons of cOttonseed oil. As it would be impossible to slip the "B" and ''C" tubes over the "A" tube when cold this difficulty is got over by heating them The work, however. re qures great care and constant atten- l tion. The heated cylinder, of course, decreases in length as well as in diam eter as 1t cools. and. unless great pre- cautions are taken, 1t would naturally 1 cool at the ends first, and cause the | central part of the tube to cool in a state of dangero us tension. To avoid such thing happening one part is cooled artifeially by means of water | jets. while the other portions are heat ed by gas flames.
 We now come to the wiring process. Layers of ribbon-like steel wire are wound outside the innermost cylinder | but one, as metal arranged in this manner wfthstands bursting strains | better than anything yet devised 1 twelve inch gun consumes no fewer l than 120 miles of wire. one-quarter | inch wide and one-siXteenth of an inch l thick
 That the shell may travel t'business l end" foremost throughout it's journey It
 must be given twisting motion round | its axis-in other words, be made to l SDlD. IulS IoAdiibu pItNthtS iAo tbi ing head over heels, as it undoubt- edly would do if not spinning. and l makes it travel farther and more ae- curately. The spinning motion is brought about by rifiing-the cutting of spiral grooves in the bore, or in side of the gun This is done by q long. hollow steel rod. which carries at nd nH entG thraa grooves at once.
 As the rifiiIg comes so near the end of the manufacture of a big gun it must be conducted with the great est care. for single badly cut groove would spoil the gun, now representing perhaps $50.000 in work and material. Indeed, extreme care and accuracy characterize every process in the mak- ing of heavy ordnance. The steel for the tubes is made carefully; the ingots are cast carefully and forged careful ly. Every tube is bored and turned tc the five-hundredth part of an inch. Though a twelve inch gun is nearly twenty inches thick over the powder chamber. each of it's various jackets must have it's proper tension in order
 to receive It's fair share of the shock
 of explosion.
 Finally. there is the breechblock-- the door through which the shell is in.
 serted It moves on a hinge and is a
 very massive a@air, weighing about half ton. Thanks to the presence of certain levers and the perfection of the workmanship, any one wiio has the knack can move it quite easily. It can be slammed and locked in about
 five seconds. The door gives entrance
 to the twelve foot chamber where the shell is placed
 The active life of gun is made up of the total of the very short periods occupied by the various shells passing through it's bore. The bore of ]
 twelve inch gun is about forty feet Ing. and the average rate at which ,.Ie shell travels through it is halfway between no motion at all and the mug gle velocity of. say. 5000 feet per sec ond. or about 1900 feet per second The rifiing of q big gun is worn out
 after HOO rounds have been fired. so that the total life is the time taken
 for a shell moving al 1,5oo feet per
 second to travel 4.J0o feet--that is, | just three seconds!
 Dangerous iiceoushs. Two unusual cases of suffering | through hiccoughs are reported In one a man had an attack of hic- coughs which lasted for nine days be- fore he obtained relief. A little girl