Litchfield enquirer., 1866-12-06
OUR NAVY. AND ITS ARMAMENT
GREAT GUNS.

GREAT GUNS.
 If the late war of the rebellion had of. fected no other object, the improvement in our naval armament and architecture would of itself be of immense importance to us, not only in defensive, but in an offensive point of view. Wooden vessels and guns {, of small calibre have been superseded by iron vessels and guns of heavy calibre; and improvements in this class of vessels have been made until they are almost invincible. It has been but Q few years since fifteen inch guns were introduced, and when the idea was first submitted they were thought l to be impracticable, on account of their immense weight and the difficulty that would be experienced in handling them. Machinery was soon introduced, however, that obviated this difficulty, and at present the fifteen-inch gun can be handled as ea- 1 silly as those of smaller calibre.
 In 1863 Gen. Rodman conceived the idea of building twenty-inch gun, but the ul- innate success of SO startling a project was doubted by those who were well posted in 1 the manufacture of guns It was thought to be impossible to cast such an amount of metal, so that it would be free from draws. charcoal holes or other imperfections It was at length decided to build two at the risk of the Government, one for the army and one for the navy, and the contract was awarded to Charles Knap, Esq, at that time of the Fort Pitt foundry, Pittsburgh Pa., who was to receive $50, 1000 for each gun. The entire machinery for boring and turning had to be got up in the new The first gun cast was the army gun, now in the water battery at Fort Hamilton. It was made of Juniata iron, and the charge for the furnaces, dimensions, &c, were as follows: Four furnaces were used, con- taining I'll ,O00 pounds of metal which was run directly into the mould. The fin ished weight of the gun is 116, 497 pounds. Rough length, 300 inches; finished length, A3 1-2 inches. Maximum rough diameter, 66 inches; maximum finished diameter, 34 inches; depth of the bore, 21O inches; weight of the shot, 1,0SO pounds It was proved with three charges of 60, three of 90, three of 100 and three of 125 pounds of mammoth powder. The second gun cast was of the Dahlgren pattern, for the navy, and was of the same measurements, with the exception that it was three feet shorter. This gun was cast on the 5th day of May, 1864, in the presence of Capt. Henry A. Wise, Chief of the Bureau of Naval Ord
 
 other navies of the world Like the army gun, it was cast from Juniata iron, 161 ,OO0 pounds being used As the furnaces were tapped and the metal commenced to flow, the gun was christened Beezsebub, by Capt. Wise, and that name is stamped in large letters on the breech under the sight mass. One of the difficulties experienced in cast ing these guns, was to obtain low enough density, and it was the opinion of the founder that to use Juniata metal exclu- sively, would give too high a density, and his conclusions proved correct, for the den sity was 7.33, and the tenacity 5000 lbs. These guns, when turned to their proper dimensions, were found to have draw holes on the reinforce and chase, but they were not of sufficient magnitude to iniure them, except in appearance. The navy gun was proved at the Proving Ground, eighteen miles from Pittsburgh, with three rounds of 60, three of eighty and two of one hun dred pounds of powder, and solid ball
 weighing 1080 pounds, and the star guage showed an enlargement of .O04 of an inch. These guns were cooled by allowing a small stream of water to run into the bore after the core barrel was removed, which took place in twenty-four hours after the cast ing. Fires were kept up in the pit for sev- eral days, and it was three weeks before the workmen could enter the pit for the pur- pose of stripping off the flask. The Navy gun was intended for the Dunder5ery, but her armament has been changed, as will be shown subsequently in this article. Itnow lies at the proving ground awaiting orders Last Spring Government determined to | arm the Pu,itan with two of these monsters, and orders were forwarded to Charles Knap Nephews, successors to Charles Knap, to build them of the same dimensions as the former. except, as they are intended for 8 turret, they are eighteen inches shorter. The contract left the selection of the metal to the founders, and also made them take the entire risk of their construction. Com mander Oscar c. Badger, Inspector of Ma val Ordnance at that post, was notified of the contract, and gave the matter his per sonal attention. The first desideratum was to reduce the density, and in order to effect this, it was deemed advisable to use con- bination of metals. The method of cast ing and cooling was also changed. The pigs were carefully selected and broken. with a view to an equal specialization of the iron, and 12O, 900 pounds of Juniata and 2l, 900 pounds of Hanging Rock Irons were used. Between seven and eight hours were consumed in the fusion of the metal, so that it ran from the furnaces very thin, the scintlations being very excessive. Instead of running directly into the mold, the four streams mingled in B reservoir, and ran from thence into the mold As it entered the mold it was constantly stirred with long pine poles, which caused it to thorougly mingle, and brought the scoria to the top. At the expiration of twenty-four hours the core barrel was drawn, and 8 stream of cold air from fan making 18O revolutions to the minute was thrown in through an eight-inch pipe. Temperatures of the pit and bore were taken three times a day, showing gradual and regular cooling of the metal. At the expiration of two weeks the gun was cool enough to be taken from the pit Specimens taken from the sink ing-head next to the muzzle-face, showed that the new process of casting and cool ing, or the combination, or both combined, had effected the desired aim, the density being reduced to 7.28. Again, after the gun had been turned to its requisite dimen- sions, it was found to be perfect casting, free from flaws of every description. The metal under the tool worked '1h hard and tough" The success of the gun was far beyond the most sanguine anticipation of the founders. On Wednesday, the 7th inst, the second of the Pavitm's guns was cast, from the same combination, and in all re- spects similar to the first, and there is no