The farmer and mechanic., 1915-06-29

fered any physical injury sach was
the demoraliZing effect of the nervous
shcck that all the men in the trench
led and did not recover balance until
they had run a quarter Of a mile
Meeting a Stan officer and receiving
from him stiff reprimand they all
returned TO their posts The whole
episode took place without any casu-
alties."
Here you see that while the men
IN 1he trenches may be securely shell
tered from bursting shrapnel still
tbey are none the less exposed to the
cohcussion and shock incident to the
exploding Of shell loaded with a
nlsh explosive. 1T is equally plain.
! then, that a shrapnel attack would be
| well nigh impotent when projectiles
OF the high explosive sort would suf-
| hce TO stun the defenders so that
charging infantry could sweep down
upon them and carry the day
| Here is one Of the impressive les
sons of the present war and it shows
the importance of ample supply of
proJectiles of this nature. Now We
| know why the British are building in
canada factories for the manufacture
OF trinitrotoluol. which the Germans
nave used SO successfully as a burst
ing charge for their explosive shells
IL was with this violent though rela-
lively safe explosive that they attack
ed the supposedly impregnable Bel
lglan forts and those other steel clad
Idefences on the French border
/ They have since used this destruc-
tive material both to blow up trenches
l and to paralyze those not inmedi
ately exposed TO the scattering frag-
ments of the projectiles 1t is vel
known that the French have used q
kindred bursting charge for their owr
shells.
II The problem Of the ordnance en-
gineer has been to make it possible
to hurl safely from a gun explosive.
OF this nature and then to time thei1
: detonation SO that the projectile:
, would burst either at a certain poin
: in their flight some fractions of
S second after hitting suficientE
! solid obstacle. 1t is a singular prop
r erty of these comparatively safe ex
: plosives that they are not set off b
flame and exploded but are arouse
p to action by a shock which cause
: ! tfIeTa to oetonate. Nv detona ton
! | meant vi.,ratory disturbance of eX
: trenfe Tapidity. the aeitating wave
7 passing through the en- ire mass wit
: such speed that the " hole body Q
the explosive is set of a unit an
ftot infiamed and consumed progress
: SiNely. 1t IS this l21s- ant propag
II ton of the detonation which bring
: in it's train the intense racking effec,
: of the so-called high explosives.
|
II this type Of attack, when they use
: Shimose powder during their wa
: with Russia. They lost a large nun
Der of their guns by reason of pr1
u mature explosions and many of the
e projectiles burst long before the
~ reached their mark but this W:
Is mainly due to the imperfection of II
e fuses employed. Ordnance enginee
@ have spent much time since in d
IS veloping fuses capable of nice al
justment and also secure against pr
i mature action.
20 Without going into the technic
y, niceties Of mechanisms of this sort
r may be said that all Of these fuS
are broadly of two classes, those tn
=, - function after impact and those tn
~ can be set to go off at different i
- - tervals during the flight of the sht
~ The latter are what are proper
y termed time fuses
"a The percussion fuse may be plac
~ either in the point or the base OF t
- - projectile, but it is always in the ba
~ if the shell is designed to penetrate
perforate a hard body before eXplo
ne ing, the point being left intact so tn
OF it can bore it's way through the o
ct struction. In substantially all Of the
z fuses there is a little weight of hal
ne mer which strikes a cap of fulnina
ut of mercury. This material, because
gaseous products develop and eXpa
en- with amazing rapidity, is capable
NY dealing a tremendous blow, and tn
al in its turn, causes the detonatlt
ne of the main bursting charge.
lis The principal problem Of the OF
,1y nance expert is to prevent the hal
Of mer from moving until the shell h
n left the gun and has travelled sol
distance in flight Then, the safe
a feature, and there are a veriety
IS these, becomes imperative and
Oft fuse is armed and ready to act wh
ost the slightest ha1ting Of the project
on causeS the hammer to travel forWa
lis and to strike the illuminate cap.
ir- Time fuses are first ignited by I
ep. propufsiye flame that sends the pl
nd iectile on its journey. The Quickn
IN with which the bursting charge
reached is determined by an eperaE
rO- called cutting or setting the fuse.
ius n,,ete from a we'll known work
roll o~r3