MECHANICS AND USEFUL ARTS, 121 



gun will be accurate, as it will have a high initial velocity, a flat 

 trajectory, and will retain immense vis viva at a long range. It 

 is not at all improbable that 25-inch guns, with 275 pounds of 

 powder, will yet be constructed and mounted on our forts for 

 harbor defence. The 20-inch gun, from Fort Pitt foundry, Pitts- 

 burgh, Pa., weighs 95,000 pounds; its greatest diameter is 94 

 inches; at the muzzle 38 and 70 inches ; length 189 inches; bore 

 157 inches. This is for navy service, and is shorter than others 

 of like calibre heretofore cast. The ball weighs 1,000 pounds ; 

 charge of powder 60 to 100 pounds. 



BREECH-LOADING RIFLES. 



At a board of officers assembled at Washington, D. C., the fol- 

 lowing report was made : that the .45 calibre ball gave the best 

 results as to accuracy, penetration, and range ; with regard to 

 uniformity of bore, that all rifle muskets and single-loading car- 

 bines used in the military service should, if practicable, be fitted 

 for the same cartridge ; that the charge for muskets should be 

 from 65 to 70 grains of powder, and from 480 to 500 grains of 

 lead. With regard to conversion they recommended the plan 

 submitted b} T Mr. H. Berdan ; this gives the stable breech-pin, 

 secures the piece against premature discharge, and involves only 

 a slight change in the present pattern. The bore of the present 

 barrel can be reduced to the desired calibre by reaming out the 

 grooves and inserting a tube. 



The following are the results of the trials of several American 

 breech-loading rifles, as reported by the New York military com- 

 mission appointed to examine them. The Roberts breech-loader 

 fired 84 balls in 6 minutes, all striking inside the target, and pene- 

 trating 15 1-inch planks laid side by side. The Sharpens rifle 

 iired 100 balls in less than 7 minutes, and penetrated the 13th 

 plank. The Mil bank rim-fire gun fired 99 balls in 6i minutes, 

 and penetrated the llth plank. The Lampson gun fired 12 balls 

 in 1 minute. Ball's carbine fired 75 balls in 9 minutes. The 

 Prussian needle-gun, which was tested in the same way as the 

 others, fired an average of 6 to 7 balls per minute, and penetrated 

 the llth plank. The Remington breech-loader fired 100 balls in 

 7 minutes, and penetrated the llth plank. 



TRIAL OF BREECH-LOADERS. 



The trials of breech-loading small arms, during the winter of 

 1866-67, by the board of officers detailed by Governor Fenton of 

 New York, excited great interest among military men and inven- 

 tors. The latest improvements and inventions were exhibited to 

 the board, the sessions of which were attended by the Russian, 

 English, Spanish, and Danish officers sent to this country by their 

 respective governments to examine breech-loaders. 



Thirty days were occupied in the examination of 17 arms, 

 of systems adapted to conversion of muzzle-loaders, 10 arms 

 not so adapted, and 3 magazine or repeating guns. The tests 



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