MECHANICS AND USEFUL ARTS. 61 



artillerists have accomplished far more than this. As long ago as 

 August, 1861, they constructed a rifled gun which, with a charge of 

 twenty-five pounds of powder, threw a projectile through the iron- 

 plated target at one thousand metres ; and, although this gun is not 

 yet in common use in the French service, several specimens of it 

 have been manufactured, and the experiments have been carried on 

 in the present year with increasing success." The writer also asserts 

 that the French model gun is not unlike the weapons with which JNIr. 

 Whitworth has obtained the startling results detailed in the preceding 

 part of this article. 



English Iron-clad Navy. The English have four iron-cased frig- 

 ates completed and in service, namely, the Warrior, Black Prince, 

 Defence and Resistance. The two former are the most formidable 

 armor-clad frigates afloat ; have engines of twelve hundred and fifty 

 nominal horse-power, and carry forty 'guns: the two latter have 

 engines of six hundred horse-power, and carry eighteen guns Arm- 

 strong one-hundred-pounder rifled, and sixty-eight-pounder smooth- 

 bores. Besides these, the English have seventeen other iron-clads in 

 the course of completion, four of which are larger than the Warrior, 

 and will be plated from stem to stern with five-and-one-half-inch 

 plates. The English admiralty are also transforming a number of 

 thirty-six-gun frigates into iron-clad sloops, by cutting them down 

 and attaching plates only a little above and below the load line, and 

 the midship part of the vessel containing the guns. 



New Austrian Guns. The improved cannons adopted by the 

 Austrian government are formed from a new alloy, called Aich 

 metal, from its inventor. It is composed of copper six hundred parts, 

 zinc three hundred and eighty-two, iron eighteen. Its tenacity is 

 said to be excessive ; it is easily forged and bored, and when cold may 

 be bent considerably without breaking ; its resistance, it is also stated, 

 is far greater than that of iron of the best quality. 



Breech-Loaders vs. Muzzle-Loaders. Some interesting experi- 

 ments to test the comparative efficiency of " breech " and " muzzle " 

 loading field artillery were made in England, Oct., 1862, under gov- 

 ernment direction. The muzzle-loading guns were four in number, 

 of Whitworth's pattern, brass twelve-pounders, rifled. The breech- 

 loaders were of Armstrong's pattern, iron twelve-pounders, with all 

 the latest improvements. The trials began by firing at a floating tar- 

 get distant five hundred yards. As the shot fell in the sea, no very 

 close comparison could be made as to the accuracy of the respective 

 hits, but both at the five hundred yards range, and afterward at the 

 twelve hundred yards, the shot from the Whitworth was the first to 

 carry away the flag aimed at, and it was generally conceded that at 

 both ranges this gun fired closer to the mark than the Armstrong. 

 Both guns were then tried with shell, the Armstrong firing compound 

 percussion shells, and the Whitworth firing a new kind of shrapnel. 

 It was observed that a considerable number of the Armstrong shells 

 burst in the air before reaching the mark, and, of course, without 

 effect ; but the Whitworth shell, being used with a time-fuse, which 

 is ignited in front like the old shell, was found to be more regular and 

 effective in its action. 



But perhaps the most interesting part of the experiments was a 

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