THE ROYAL ARTILLERY INSTITUTION. 
275 
(2) The weight of the projectile; in proportion to which it is enabled 
to overcome the resistance opposed to it, so that the greater the weight 
the more power the projectile has of overcoming the resistance. For 
instance, a heavy train requires more resistance to bring it np than a 
light one, supposing both to be travelling at the same rate. 
Combining these two reasons into one statement, we say that the 
power of overcoming the resistance of the air for any gun varies directly 
as the weight of the projectile it throws, and inversely as the square of 
the diameter of the bore. 
Thus, 
T, c weight of projectile in lbs. 
rower or gun a- n - ; — : —-— 
square of the diameter m inches 
supposing the projectiles to have the same muzzle velocity. (See 
Table I.) 
Table I. 
m 
Table shelving the relative Tower of Guns in the Service. 
Nature of gun. 
Weight of 
shot. 
Diameter 
of bore. 
I 
Weight in lbs. 
Square of dia¬ 
meter in inches. 
Snider-Enfield... 
480 grs. 
ins. 
0-577 
206 
M artini- Henry . 
480 it 
0-45 
339 
9-pr. M.L. 
9 lbs. 
8-0 
1000 
12-pr. M.L. 
12 „ 
3-0 
1333 
16-pr. M.L.... 
16 « 
3-6 
1234 
20-pr. B.L. 
20 »* 
3-75 
1422 
64-pr. M.L. 
64 ,, 
6-3 
1613 
7-inch M.L... 
115 « 
7-0 
2347 
9-inch M.L. .. 
250 b 
9-0 
3083 
10-inch M.L. 
400 d 
10-0 
4000 
16-pr. M.L. 
16 
3-4 
1384 
16-pr. M.L. 
16 
• 
3-3 
1469 
I know that practical men place very little faith in mathematical 
formulae, and I believe they are right to a certain extent, for the basis 
of many mathematical formulae is only a hypothetical condition not pre¬ 
cisely true in actual practice; but this does not belong to that category, 
for it is the expression of an actual experimental fact, verified by 
Professor Bashforth in his experiments at Shoeburyness on this parti¬ 
cular subject. 
Now let us compare by this method the “power” of the Martini- 
Henry and Snider rifles, both of which throw a 480 gr. bullet. 
Martini-Henry 
w _ -06857 
d 2 “ (-45)2 
w _ *08857 
d 2 " (-577 f 
= -0339 
=*0208 
Snider 
