El Paso herald. (El Paso, Tex.) 1901-1931, 1918-06-13

necessary such changes In the pro-
jectile- Both lower and upper belts
surround the grooves and these
grooves must fit into those Of the
barrel with extreme precision and
without any forcing. Their service is
triple- to Increase the velocity OF rota-
tion and consequently the steadiness
Of the projectile; to divide the weight
which presses upon the copper belts
II they alone support but which are
nevertheless able 20 bear a weight
that harder metal could not support:
eventually 10 prevent the vent" or
Wlndage, that is. the escape Of gas.
The grooved projectile is not a nov
city known in France for a long
time. IL constitutes one Of the pecu-
liarities Of the Baziu projectile.
The cap with which the proiectile
Is provided gives il pointed shape;
this permits OF a better center Of grav-
ity in the steady cylinder
The charge is introduced from be-
hind and between the rocket and the
basecup Of the projectile. This rein
forced capsule has a heveled edge and
thus diminishes IN slight degree the
resistance Of the air at the end
As TO weight. one always expects
one Of 100 kilos four go weighs 300.
The prOjectile, short and relatively
light, would be OF no use in the nor
NAL conditions OF the resistance OF the
air.
The double rocket is undoubtedly
the second best lodged in the base Of
cup Of the proiectile.
Probabilities OF Non-EzpIosion.
The projectile has not been found
that viii not explode. It IS normal
In fact. well constructed rockets show
an average Of six percent Of failure.
II one uses a projectile with two
rockets the probabilities Of failure are
= a b #HH az HraaHs
words, there is a chance Of failure in
800 shots This IS the only way TO
calculate the probabilities.
How One Hears Noise Of Gun.
The way in which one hears the
stroke Of the cannon has given rise
20 number Of stories. or legends they
are, OF which the most terrifying are
those circulating the theory that
compressed air cannon has been in
stalled by a SPY at the gates OF Paris
Some officers commissioned To listen
at about go kuometers from the line
OF fire. reported sometimes a single
defamation. sometimes one followed by
another at an intervals Of several sec
0nds-
The whole thing explains itself by
the complicated phenomena Of ac0us-
tics. in substance as follows.
The shot Of the cannon makes two
noises; that Of the explosive wave and
mat VA AAAN p We va AA.N HAANNH aAAA-
ing from the blow Of the projectile
upon the air.
How the Sound Travels.
The explosive wave follows at first
the path OF the projectiie with a
greater velocity than its own; then
at the end Of a very short time 10
spreads out and goes at its own We
locity. II the path is very much
curved, this velocity can be greater
than the horizontal velocity OF pro-
jectile going at a greater speed
The wave OF the shock follows the
projectile, forming behind Il a wake
or aerial track similar to the wake
OF boat I'm the water At the top Of
the wake, that is TO say IN the line Of
the curve, the wave has an equal We
locity TO thas OF the proiectile; but
upon the sides or outer edges OF the
path il is proceeding at its own We
locity, forming thus a series Of waves
quite complicated.
Other Hypothesis.
We have heard OF the projectile OF
Baxin. The bomb thrower was used
in 1871. at Saint-Ouein in the batteries
OF the captain Of the frigate Bray. un-
der the auspices Of admiral La Ron
ciere lie Nourry. This projectile had
total weight OF so kilos, the last
rocket was grooved fin a way TO as
cure the continuation OF direction af-
ter the final division Of the rockets.
The calculations gave an initial We
locity OF 335 meters; falling to $50 me-
ters at the summit Of the parabola.
The shell left the barrel with an ini-
tial velocity Of sos meters.
One cannot with any eXactitude fig
ure upon the number Of large guns
possessed by the enemy. One hears all
sorts Of things even that one Of their
guns has exploded. The thing is quite
possible. as one can see that the en-
envy artillery might have been con-
structed with the normal coefficient Of
safety considerably lowered But
these news have been carried BY rris- I
oners or by refugees and Sc is prudent /
10 accent them with reserre.