The daily Alaskan., 1917-12-20
THE BIGGEST GUNS
Those Used on Land Outweigh the
 Largest In the Navy.
OUR COAST DEFENSE GIANTS.


 Hook and Panama Can Sink VSsssl
 Before It Appears Above the Horizon.
 How the Big Guns Arc MadO.
 There are two classes of guns-naVal guns and army or land guns. Because they can be manipulated more easily than those of a ship, land guns are the heavier. The largest naval gun is the fifteen inch gun, and the largest land gun Is the German howitZer, or 16.5 inch gun.
 Of the two the naval gun fires a shell weighing over half q ton, while, the other fires prGjectIe ton in weight. But the new giant sixteen inch guns of the United States defending the Panama canal and New York at Sandy Hook shoot proJectiles weighing 2,3T0 pounds, which Is over ton. These immense steel guns can sink ship be- fore it has really come into sight on the horizon, the location of the battle ship having been determined by air plane or tower.
 How these huge pieces are made is described as follows by the Popular Science Monthly. The first step is the making of the pig iron from iron ore in large furnaces like towers, called blast furnaces. Then the pig iron is melted with other steel ill large steel furnaces called "Open hearth" until 1t is freed of its Impurities and convert ed into steel.
 The melted steel, thin as water, Is run from these furnaces into big iron molds, where 1t is allowed to cool Into large solid cylindrical or corrugated blocks. After cooling these are reheat- I ed and reduced in size by pounding Il them with big steel hammers and | squeezing them in rolls until Rt last l the steel is pressed into long barrel 4 like mass, the embryo of real gun. This long skeleton of the inside of 1 gun must be bored out from one end I to the other on immense latheS, some over ninety feet long. Heavy as the mass is, q huge lathe turns 1t around as easily us body turns a spool. rI After the inside has been rited or scored to form an inside surface that I gives the shell n twist before 1t leaves l the muzzle and causes it to fly straight I the lower or muzZle end of the gun Is I made larger. This may be accomplish ed in ore or two ways. Either addi- tional shorter steel tubes are placed | over the main inner tube, or tue main | tube is wound with wire and finished with an outer tube. The wire wound guns are usually the heavier and are used on board ship.
 The gun bound with wire Is really ] stronger than the one built of bands or l rings of steel, one on another, for the l wire re-enforceS the gun tube so that 1t will safely withstand the tremendous strain which is constantly put on It when 1t Is fired, said to be as much as seventeen tons pressure on each square inch.
 In the case of built up" gun, as 1t Is called when made of hoops or bands of steel the outer tubes or rings II are shrunk or sweated on-that is, they are heated so that they expand or swell Il little, as all steel does when heated, \ and then while hot they are fitted over the inner part and allowed to cool and shrink. or contract. In so doing they st very tightly on the main tube.
 In making a wire wound gun the wire is wound or coiled around and around until more than 100 miles or IL has been wrapped around the big can non, A twelve inch gun requires H. miles of wire. weighing about thirteen and one-half tons Although the strength of the wire Is such that 1t gives great resisting force to pressures exerted sideways, 1t does not bestoW strength lengthwise. Therefore an e1- fra thickness of metal must be put on the muzzle of the gun. where the VI bration caused by the shell leaving the gun is the greatest.
 The breech, or the back end of gun, is & very important part. Here the shell is inserted in a specially built chamber. After the shell Is in place the breech Is closed by the shuttlhg oA very complicated and strong door. l It is fastened or fitted in the gun by extremely strong screws, so that the charge will not burst the gun open at the back when 1t is fired.
 Sometimes a shell explOdes in the barrel of the gun. In a wire bound gun the wire tends to prevent a grave disaster. It flinders the steel tubes from bursting into many pieces and flying in every direction. The solid gun is wholly built of tubes. while in the wire wound gun there may be one or two tubes, over which the wire Is wound with the jacket tubes shrunk over the wire. A bush for the breech ring is screwed into the rear end, which Is also re-enforced by a breech