COAST. I ARTILLERY JOURNAL, - Air Defense Artillery

466 THE COAST ARTILLERY JOURNAL
Durning is in progress, and the exploder is connected to the cable by the foreman
after everybody else is clear.
Special Precautions.-a. The composition 80/20 to be prepared as prescribed;
if too much Ground Flare composition is used it will cause a "choke" in the mouth
of the shell, and will not ignite in most cases; but if it ignites, there will not be
sufficient outlet for the flame and gas, whereby it could cause "burning" to become
"detonation" in view of the "slag" existing. b. The sludge to be put in the
mouth of the shells in any case must not be pressed down, but put in lightly.
c. After the shell has been burning for one and a half hours (9.2-inch) the burn.
FIG. 3
SO/77P/"0 coIkc/ ff~r
Corru~hd
fro/? 5/Jeet
ing ground may be approached (4, 5-inch, 4{J minutes; 6-inch, 1 hour; 8-inch, 1.25
hours). d. IT the shell has not been ignited, the mouth of shell should he cleaned
out and the process repeated.
Note on Picric POlnler.-Yery hygroscopic and when moistened is useless as
detonator for picric acid; when ignited unconfined it burns slowly with black
smoke; when confined it detonates; useless as detonator for TNT (and AmatolJ.
This powder is a mixture of ammonium picrate and saltpeter. Ammonium picrate
itself does not explode when heated in the ordinary way.
UPPER-GRor:'\"D L.AYOUT
Figures 5 and 6 show quite clearly the arrangements and corresponding dimen.
sions. When the electrical cahle is absent the ordinary train of cordite may
simply be used; all other arrangements, as have been already stated, must be
strictly carried out. For instance, when someone, not liking to carry out our rules,
placed the shells in the holes ...ithout tanks filled "Withwater, an explosion occurred
at once as shown in Figs. 7 and 8.