The Arizona sentinel., 1889-10-19

the gunmakers had to provide some
means of protecting their guns from
the violent strains set up by the press
ure : of the powder gases. Then i
was that the principle building VI
guns by shrinking types over the tube:
was introduced, and this system was
almost perfected in the high-powel
built-up guns of to-day, which form
the armament of every military power
slow powder followed the wrought.
iron built-up gun, and forced another
change in the manufacture of ordi.
nance. The gun had to be heightened,
and, in consequence, breech loading
became a necessity and not matter
of choice. By increasing the length
of the bore and chambering the piece
the charge of slow powder was great
ly increased, and in the navy guns the
rule for the charge is one-half the
weight of the projectile for a gun thir-
ty calibers long.
The products of combustion of pow
der are liquids and gases, and the
actual temperature about 3. 800 deg.
Fahrenheit At this temperature the
volume of the gasses is about 5000
times that of the powder, but when
cooled down to the ordinary tempera-
ture it is about 2S0 times greater.
Brown powder, when fired in a gun,
leaves a reddish deposit in the cham
Der. and on the face of the breech
plug. This deposit, when cool, is
readily faxed off. 1t is composed Of
sixty-four per cent. of potassium car
Donate, fourteen per cent. of potassium
bicarbonate, and twenty-five per cent.
of potassium sulphate.
The knowledge of what actually oc-
ours in the charge during the COM
bustion must, of course, be altogether
theoretical, but it is probable that
Eugene Du Points theory is not far
wrong. He says:
The action of such powders seems
to be as follows: Upon firing the
charge the gases confined in the pow
der are released and act to eXpel by
their expansion the projectile toward
the muzzle of the gun. This term
the first explosion At this time
the oxygen and hydrogen are released
as gases, but under too great heat to
unite in the form of steam. AS the
pressure is decreased by the motion of
the projectile in the gun this heat also
decreases, and the gases-oxygen and
hydrogen-unite in the form of water.
The heat generated by this union at
once changes the water into steam,
this expansion, which takes place be-
fore the prOjectile leaves the muzzle
of the gun, term the second explo-
sion. There is thus formed a powder
of great explosive force, which acts
twice upon the prOjectile. / have also
found that such powders are very ef-
fective in dissipating the smoke aris-
ing from the discharge, owing, as l
suppose. to the fact that the steam,
generated as above stated, cOndenses,
and in so doing, absorbs large quanti-
ties of the carbonate of potash, the
solid portion of the result of decom-
position of charge of powder, and
that portion which forms the smoke"
All the brown powder for the navy
is manufactured by the Du Points, and |
before acceptance it is sent to the |
Naval Ordnance Proving Ground to be
tested. Its physical qualities are de-
termined at the powder yard, and at |
the proving ground it is fired for ve-
locity and pressure. The Government |
specifications require a pressure of
fifteen tons per square inch in the |
chamber and a muzzle pressure of 2, 900
feete per second. The velocities are
by the BOulenge chronograph |
and the pressure by the crusher gauge
The specific gravity of brown powder
ranges from 1921 in the 5-inch B. S.
R. to 1855 in the 10-inch B. S. R.
The attention of the general public
has lately been called to so-called
''smOkeless, " and even noiseless pow
1ers. There are several patents on
5he former class of powders, and
ochultze's powder is an early example
Of it. They are all of nitro-cotton or
other kind Of nitro-cellulose, specially
5reated with the view of producing a
substance, or of nitro
ylycerine or nitrO-cotton. The French
nave adopted a smokeless powder
(Poudre b for the Lekel rifle. This
S said to possess high ballistic quail
les, and to produce very little smoke;
1ut it is also reported to be very deli
Iuescent Prof. Deering, chief assist
INT chemist in the War Department,
n a recent lecture summarized the
yiews of a French writer on smokeless
powders as follows:
LAS regards the influence which the
lse Of a smokeless powder would have
m tactics, the writer remarks that the
ubject is at present conjectural, but
ONE obvious consequence can be fore
cen. In the case of artillery, the use
# smokeless powder against an enemy
provided would render pre-
ision Of aim possible, and would al
Ow tho affaot of fro +O bo soop A | .