caking. This
was accomplished by using underburned charcoal, together with sugar
and about one and one-half per cent. of water. This is the brown
powder most generally used at present and with satisfactory results;
but the abstraction of its moisture increases its rapidity of
combustion to a dangerous degree, besides which the underburned
charcoal is itself unstable.

The next change demanded is smokelessness, and to accomplish it
recourse is had to the high explosive field, mechanically mixing
various substances with them to reduce and regulate their rapidity of
action. Just now some form of gun-cotton is most in use mixed with
nitrate of ammonia, camphor and other articles. The tendency of these
mixtures is to absorb moisture, and the gun-cotton in them to
decompose, and there is no smokeless powder which can to-day be
considered successful. Such a powder, however, will undoubtedly be an
accomplished fact in the near future. Military men seem to be a great
deal at variance as to its value in the field, but there can be no
doubt of its value for naval purposes; it is a necessity forced upon
us by the development of torpedo warfare.

First came the simple torpedo, at the end of an ordinary boat's spar.
Then came the special torpedo boat with its great speed, then the
revolving cannon and rapid-fire gun to meet the torpedo boat. At
present the possible rapidity of fire is much greater than can be
utilized, on account of the smoke; hence the necessity of smokeless
powder. Smokelessness is, however, principally a martial demand that
has been made upon the science of explosives and has attracted public
attention on that account. The commercial demands for various other
properties have been much greater than the military, and between
gunpowder near one end of the line in point of power and
nitro-glycerine near the other, there are now over 350 different
explosives manufactured, and most of these have been invented within
the last twenty years.

The simplest application of high explosives in warfare is in
connection with torpedoes, since within the same bulk a much more
efficient substance can be obtained than gunpowder, and with
reasonable care there is very little danger of premature explosions by
reason of accidental shocks.

Torpedoes were made by the Chinese many years ago, they were tried in
our war of independence, and also by the Russians during the Crimean
war; but the first practical and successful use of them