Evening star., 1901-02-25

broke the glass tube, which caused spark
to pass at both breaks. the second one
serving to light up the cylinder, which was
photographed by camera in the axis of
the reflector.
The first series of experiments showed
that with the apparatus above described
and the ammunition used there was no evil
dence of any bulgng out of the exit sur
| face up to the time the projectile reached
| this surface: the bulging began after the
projectile had passed through. While the
projectile is still in the interior the water
| flows in jet through the entrance hole
toward the gum but the explosive action
| OF the contents of the cylinder, tearing the
latter in all directions, takes place only
after the bullet has passed completely
| through the cylinder.
With larger and stronger cylinders and
higher velocities very different results
were obtained, was shown when wrought
iron cylinders. three feet long and "a
inches in diameter We're used closed at the
ends with rubber and parchment paper as
before: The explosive action while the pro-
Jectile was still inside was then distinctly
perceptible and very energetic. The pro-
1ectie lost It's velocity before reaching the
exit wall, and was upset and f1attened at
the front and much torn. and finally swept
out by the jet at the entrance hole. The
parchment paper at the exit hole was torn
into zigzag form and bulged out toward
the gun. The rubber sheet at the exit wall
was torn In different ways, depending on
Its tension; sometimes showing only a
r.
cular hole-sometimes slit
with the view to explain the cause of this
explosive action of rapidly moving small
arm proJectiles other experiments were In
stituted. The explanation reached by the
experimenters is as follows:
Ihe rapidly moving projectile produces
compression wave in front Of 1t, and the
result is a motion Of translation Of the en-
tire mass fired through, causing q greater
or smaller tearing effect on the containing
walls, depending on their resistance The
action consists in the projectile giving up
Its energy of motion to the body struck,
when the lateral effect Cor explosive action)
Is greater; the more direct this giving up
Of kinetic energy Is Qn other words, the
greater the portion of the body that IS
struck directly the smaller the amount or
energy used up in overcoming cohesion IN
the body: the less the internal friction and
the smaller the mass of the body struck
When very large masses (of moist clay,
Tor eXample) are struck the hole inside OF
the mass Is OF peculiar crater-lke form.
narrower at the entrance than Just within
and finally tapering to a point where the
bullet comes to rest. IL sections are taken
at various points through the crater-like
hole In the clay mass exit holes of different
dimensions will be obtained This explains
bullets, for with a comparatively thin plate
of clay the exit hole would be a little larger
than the entrance hole, and with a thicker
plate much larger after passing the point
hole the exit hole grows smaller and small
er. So it is in the human body, the resist
ance offered corresponding to the thickness
of the clay plate.
The explosive action is always greatest
in the lines of least resistance, as is known
to be the case In a very remarkable manner
with high explosives.
This subject is one of great interest IN
the supposed uses of explosive bullets so
much talked about in the Boer war.