MECHANICS AND USEFUL ARTS. 87 



piece is first withdrawn, and the breech slid back clear of the barrel into 

 the space vacated by the wedge piece. A small finger lever at the side 

 slides back to the breech, which is then turned up and receives the charge ; 

 then it is brought down again into line with the barrel, slid forward, and 

 forced into position by the wedge piece described. The movable breech in 

 this rifle is a charge chamber, and appears to be a supplementary device to 

 Sharp's rifle. 



Monster Gun. Messrs. Horsfall, of Liverpool, England, have during the 

 past year constructed and presented to the British Government, a piece of 

 ordnance of most enormous dimensions. The process of fabricating this 

 huge mass was very simple. Square slabs of metal, of about 3 feet long by 

 14- broad, were welded together, and as layer after layer was added to the 

 mass the slabs were reversed in various directions, till the bulk presented to 

 the eye the appearance of a huge, solid lump of iron, slightly conical in form, 

 15 feet long, 3 feet 10 inches diameter at the thick end, and tapering to about 

 2 feet 10 inches at the small or muzzle end. It then weighed nearly 26 tons. 

 Great care was taken, and all that science could suggest was brought to bear 

 upon the process of fabrication, which lasted seven successive weeks, day and 

 night ; but the material was during that tune regularly allowed to cool from 

 Saturday night to Monday morning. Great care was taken to prevent the 

 mass from receiving the blows of the hammer, or percussion from any other 

 cause, while it was cold, or in a semi-heated state, in order to avoid the 

 disintegration known to be produced in iron when hammered cold. Forty 

 men were at times employed upon it, and the hammer used weighed nine 

 tons, striking at every blow equal to a force of twelve tons. 



After the mass had been roughly shaped, the process of boring was com- 

 menced, the first bore being with an eleven-inch cut. The material proved 

 to be all that could be wished not the slightest indication of crystallization, 

 brittleness, fault, or looseness of texture w r as manifested. There had not 

 been the slightest imperfection in the forging. It was next bored with a 121- 

 inch cut, and finally with a 13-inch the distance bored being 13| feet. After 

 this process, the piece was finished in the ordinary manner, though in 

 superior style. The nett weight of this piece of ordnance, after comple- 

 tion, was 21 tons 18 cwt., having been diminished a little over four tons 

 by turning and boring. This was nearly three tunes the weight of the 

 great Stockton gun, which weighed 7 tons 17 cwt. Its diameter at the 

 breech is 44 inches; at the muzzle 27 inches; thickness of metal at the 

 breech from the bore to the outside, 15 inches; thickness at the muzzle 7 

 inches. 



The gun is discharged by means of a percussion hammer affixed at the 

 breech, and such is the machinery connected with the raising and lowering 

 of the instrument that a child might almost elevate it or depress it when in 

 the stocks. It is capable of receiving a ball 302 pounds in weight, which, 

 with a discharge of 90 pounds of powder, is expected to be projected at 

 least five miles. The capacity of the Princeton's gun was for a bah 1 of 219 

 pounds. 



