The Wichita daily eagle. [volume] (Wichita, Kan.) 1890-1906, 1898-04-17

The popular idea OF an explosive is
substance which Is capable of inslanta-
neous combustion In & confined space TO
which no air is admitted Although the
term burning Is freely used in speaking
OF powders. it is little understood that
the various explosives have different rates
Of combustion, emitting them 10 be term
ed either slow burning or quick burning
Or decorating. IS the case may De. As
far as our senses are able 10 inform Us
all explosives are instaneous. and il would
seem as though the solids were converted
into gases in literal instant OF time.
AS a matter OF fact. however. there is
a difference in the rate OF combustion
which is sufficient TO divide explosives
broadly into two classes, those which are
detonated ard those which are quick
burning and slow burning. Decorating ex-
plosives are those in which the explosive
is consumed simultaneously, or practically
so. throughout its entire mass by what
is called a wave action The generation
OF gas is so complete and instant as 10
produce a disruprive or shattering effect.
which renders such explosives useful for
blasting purposes. but UNITS them fer use
in rifles or artillery.
In the gunpowders as distinguished from
decorating explosives the combustion
takes place upon the surface of the solid
particles composing the powder. and an
appreciable period of time is consumed in
their combustion. AT the moment the
powder IS ignited. the consuming fame
attacks the whole surface of each grain.
whether the grain measures a cubical inch
in bulk. as in the powders of heavy guns.
or whether it be the size of pin-head. as
in the common black powder.
ha II
not a decorating powder. was consumed
with such rapidity that the whole of It
| was converted into gas before the shell
had moved forward twelve inches in the
gun. and the expansive force OF the gas
hten served TO further accelerate the shell
during its travel through the remainder
| OF the bore. This brought very high
initial pressure upon the gun and prevent
ed the use OF sufficiently large charges
OF powder to give high velocities.
1t was found, however, that by COM
pressing the powder into cakes. the tital
area exposed to the flame was reduced,
and hence the time of combustion was pro
| longed. The result was that the PRESSURE
was produced gradually during tho travel
of the shell toward the muzzle. the press
ure being spread out. as it were. over a
I large area of the bore. The resulting We
locity of the shell was the same. the diff
ference in the action OF the powder being
the same as that between a blow and a
push. but there was the added advantage
that the initial or maximum strain on the
gun was less. The ideal powder would
burn at such a rate that sufficient gas
would be generated TO maintain a con-
slant pressure behind the shell through
out the whole legnth of its travel, through
the gun. At the same time il should be
consumed at such a rate that no unburnt
powder should escape with the gases.
The smokeleSs powders. because of the
small quantity or solid products OF com
tUstion and the great volume and high
temperature of the gases enabled the ar
tilleries to secure velocities far in excess
OF those obtained by the use of The cid
pow ders.j Moreover, smOkeless powders
lent themselves to the formation OF pow
der eraIns which would insure ;he very
best control of the combustion OF the
powder.