THE 80-TON GUN. 
353 
the outset—viz., to produce a gun whose projectile shall be able to 
pierce 20 ins. of well-backed iron aj 1000 yds.—let us see how we 
stand. Of the various calculations for penetration before mentioned, 
that put forward by Major W. H. Noble is the most favourable to the 
gun, and that worked out by Lieut. English, R.E., is the most favour¬ 
able to the plate.. It must not be forgotten that the dimensions of the 
gun were determined on the basis of a 16-in. calibre, throwing a 1650-lb. 
shot with a muzzle velocity of 1400 f.s. We have already got a 1260-lb. 
shot starting at 1543 f.s., and a 1465-lb. shot at 1440 f.s. Hence it is 
as certain as anything connected with powder can be said to be certain, 
that we shall be able considerably to exceed the anticipated velocity in 
the 16-in. calibre. Our powers of predicting results have been very 
greatly increased by Capt. A. Noble's “Researches on Fired Gunpowder," 
alluded to above j and as far as calculation may be trusted, we ought to 
get in a bore of that size a muzzle velocity of 1535 f.s. with a 1650-lb. 
shot, or of 1488 f.s. with an 1800-lb. shot. Now, the gun in its present 
state at 1000 yds. will penetrate according to 
ins. 
Lieut. English . 18J 
Major Noble .... 23 j 
while in its 16-in. calibre, if the power expected as above be realised, 
the penetration at 1000 yds. with 1650-lb. shot will be, by 
ins. 
Lieut. English . 20 
Major Noble .... 26 
and finally, with 1800-lb. shot, by 
ins. 
Lieut. English . 20| 
Major Noble ... 27 
From this result, it seems that in all probability the gun will be suc¬ 
cessful in performing the task allotted to it; and it only remains for 
me to state, in conclusion, that if, after all, it turns out that it cannot do 
the work, the Royal Gun Factories are quite ready to make one that 
can. 
January 19, 1876. 
