MECHANICS AND USEFUL ARTS. 115 



the Whit worth, in the battery 204 yards from the target, which 

 was standing in the water. The shot passed through the 5-inch 

 iron plate, the 18 inches of solid oak, a brace behind it about a foot 

 thick, in which it broke off a 1-inch bolt. 



Now, instead of using but 18 pounds of good strong powder in a 

 5^-inch bore gun, as was used in that Whitworth gun, which filled 

 it 25 inches deep and spoiled it, we would use 5 or 8 times 18 

 pounds in the accelerators, which would be enough to fill the bore 

 from 9 to 14 feet deep, if it was in the bore of the gun. That and 

 the shot would more than fill the gun. But the powder being ail 

 in the accelerators except the 3 pounds of very slow powder, it 

 fills the bore but 4 inches deep, and though the pressure is not 

 raised one-fourth as high in the accelerator, the power exerted is 5 or 

 8 times as great as it was in the* Whitworth cannon. 



The reason for the comparative increase of range for every in- 

 crease of elevation is the fact that our shot are more than twice 

 as long and heavy as Armstrong's or Parrott's in proportion to 

 their diameter, and therefore meet with much less resistance from 

 the air in proportion to their momentum, notwithstanding their 

 higher velocity. 



If this 6-inch shot, propelled by 120 pounds of powder, of which 

 90 pounds is quick and strong, averages 1,666 feet per second with 

 5 elevation (and it will more than that if properly modelled 

 for overcoming the resistance of the air), it will range 5,000 

 yards ; that is, more than twice as faras any other gun, and more 

 than 3 times as far as the 15 or 20 inch bore gun of the monitors. 

 At 5 elevation, or 5,000 yards, it will penetrate at least 16 inches 

 of iron plate and 4 feet of oak ; that is, it will pass through and 

 from side to side of any- iron-clad vessel that can be floated. 



The limit of the elevation of the 15 and 20 inch guns on the 

 monitors is 6, and their greatest range is less than 2,000 yards. 



It is evident that two or three active wooden merchant' vessels, 

 properly prepared and each armed with one or two of these accel- 

 erators, would destroy a whole fleet of monitors or slow iron-clads 

 without allowing them to approach near enough to roll their 15 or 

 20 inch shot within half a mile of them, or endanger them in the 

 least in any way. 



NOTE. A similar gun is described in the " London Mechanic's 

 Magazine " for May 24, 1856 ; and also in Mr. Holley's work on 

 "Ordnance and Armor." 



Perhaps gunpowder with gun-cotton would answer better than 

 powder alone, from the difference of rapidity of explosion, 

 the slowest to be ignited in the cartridge first. EDITOR. 



THE GATLING BATTERY. 



This gun differs essentially in mechanical construction and op- 

 eration from all other fire-arms. It may be justly termed a ma- 

 chine gun, as it is automatic in its operation, loading and firing 

 by mechanical agency without cessation, simply by turning a 

 crank. The gun bears the same relation to other fire-arms that 



