Guns and Projectiles. 121 



predicted that they would not do for shells ; but Sir William 

 Armstrong- proved that, on the contrary, they would fire a 

 more destructive kind than had been previously employed, 

 while Mr. Whitworth demonstrated that if made of the right 

 pattern, they could be easily driven through any of the iron 

 ships in the navies of England or France. 



When projectiles are fired from guns, their velocity di- 

 minishes as they proceed, and no attempt has as yet been suc- 

 cessful to give the requisite accuracy to rockets, which supply 

 their own motive power as they go along'. Sir William Con- 

 greve did much, and Mr. Hall improved upon his plans; but 

 no rocket has yet approximated to the accuracy of a shot re- 

 ceiving its impulsion from a charge of powder in a gun. An 

 ordinary projectile suffers no change in the position of its 

 centre of gravity during its course ; but a rocket carries a 

 composition that goes on burning, and thus it may be said to 

 be continually discharging ballast, and shifting its weight. 

 Whether this will ever be compensated, and whether it will 

 also be found possible to regulate the direction and force of the 

 gases discharged from its tail, we do not venture to say ; but 

 if some future Whitworth could perfectionate a rocket fired 

 from a rifled gun, it would probably penetrate anything that 

 could be made to float. 



The size of ordnance is almost as important as their con- 

 struction, and perhaps a rule might be laid down to use the 

 biggest that all the circumstances conveniently permitted. 

 There are cases in which small guns fired often, would be more 

 advantageous than big ones fired at greater intervals ; and it is 

 certain that monsters could not be fired as often and as quickly 

 as those of moderate size. In other cases, as in attacking 

 ships or forts, size must be an important element of success — 

 a single shell of great bulk being able to destroy any vessel it 

 could penetrate, or blow up an immense quantity of earth or 

 stone work. Should our engineers succeed in constructing 

 really serviceable guns, capable of throwing 1000-pound shot 

 or shell, ships might become simply floating stocks for one or 

 more of such barrels, and in any case it may be doubted 

 whether leviathan vessels that offer so much to shoot at, and 

 are so difficult to manage, will maintain their ground. 



Wc shall, in conclusion, say a few words on explosive sub- 

 stances, and their action. In dealing with a projectile you 

 wish to communicate to it, as a whole, as much motion as you 

 can. When your powder is exploded, a solid is suddenly con- 

 verted into gases, which, in a highly heated state, are supposed 

 to occupy more than 2000 times the original bulk. Tho velocity 

 of the transition from tho solid to the gaseous state is also 

 enormous, though far less than in certain other compositions of 



