shell with the two harmless constituents of an explosive and having
them unite and explode by means of a fulminate fuse on striking an
object. He used for the constituents nitric acid and dinitro-benzine,
and was quite successful; but the system has not met with favor, on
account of the inconvenience. The explosive was about four times as
powerful as gunpowder.

That the advantage of using the most powerful explosives is a real one
can be easily shown. The eight inch pneumatic gun in New York harbor,
with a projectile containing fifty pounds of blasting gelatine and
five pounds of dynamite, easily sunk a schooner at 1,864 yards range
from the torpedo effect of the shell falling alongside it.

This same shell, if filled with gunpowder, would have contained but
twenty-five pounds, and have had but one-ninth the power.

The principal European nations are now building armored turrets sunk
in enormous masses of cement, as a result of their experiences with
gun-cotton and melenite. The fifteen inch pneumatic projectile, which
I described as being capable of sinking an armorclad at forty-seven
feet from where it struck, would have been capable of penetrating
fifty feet of cement had it struck upon a fortification. It was not
only a much larger quantity of high explosive than Europeans have
experimented with, but the explosive itself is probably more than
twice as strong as their gun-cotton and five or six times as strong as
their melenite. In the plans of Gen. Brialmont, one of the most
eminent of European engineers, he allows in his fortifications about
ten feet of cement over casements, magazines, etc. It is evident that
this is insufficient for dynamite shells such as I have described.