Vermont phÅ“nix. [volume] (Brattleboro, Vt.) 1834-1955, 1873-09-05
Important Tests Of FireprOor SAFES by
the English Gorernmenf.
rIREpRoor GUNrowDER MAGAZINE.


'Some experiments as 10 the storage of
gunpowder have been recently tried at the
Practice Range, Plumstead Marshes, at the
instance OF the Home Secretary and by per-
mission of the Secretary of State for War.
With view TO guard against the danger of
explosion, Messrs. Miner & Co., of Liver
pool, have designed fireproof safe, 10 hold
small quantities of gunpowder, and the ex-
periments were made to determine how far
Those miniature magazines will preserve
their contents from explosion when expos
ed to the action of fire.
Four magazines were put to the proof.
In form, they differ in no respect from any
ordinary tireproof safe. They are formed
of four inch chambers, between each of
which Is stuf1ing of alum and sawdust.
The action of heat dissolves the alum, which
contains 81 per cent of water and tho liq-
uid portion finds its way through small
holes in the safe, wetting any loose pow
der, while that contained in cauisters is SO
protected as to be non-explosivc. This, at
least, was the theory of the manufacturers.
The value of the theory was now to be
tested.
In the open air, several hundred yards
apart, four furnaces had been erected, each
seven feet in internal diameter, and each
heaped up with wood, shavngs, coal, and
q dash of petroleum TO assist ignition. All
the magazines were of the same size, and
made TO hold one hundred pounds of pow
der loose or in canisters, as it is generally
kept by retail dealers and sportsmen; but
for the purpose of experiment, only a small
quantity of powder was placed in each, put
up in different ways, some in paper, some
in canisters, some in barrels, headed up
and open. In each magazine, there were
placed two of Negretti & Zambras self
registering thermometers, with 2l little
sticks of alloy, Tin and lead), so made un-
der Professor Abeps directions as 10 melt,
according TO the varying proportions OF the
alloy, at varying degrees of temperature,
from 3i0o to $3.50 Fair. Gunpowder ex-
plodes at n temperate of 5000; but long be-
fore this degree of heat was reached, 1t was
expected that The sulphur would be yola-
tilted, when the remaining constituents
would be robbed of their chief powers for
mischief.
BY IL. 80 A. NJ, all four furnaces were in
| a blaze, and there could be no doubt as 10
the rough reality of the ordeal which the
| magazines we've undergoing. AS the wall
of coal gradually burnt through and the
| flames rose high above the buried maya
zines, there seemed to be no wish among
any visitors TO disobey the earnest request
addressed to them, not to approach the
| furnaces during the progress of the exper-
| iments. There was little, indeed, TO tempt
visitors from cover. The rain poured down
| necessarily during the greater part of the
| day, and Plumstead Marshes, at no time
| very lively, became dismal swamp in
| deed. Meanwhile the fires burned furious
| ly, nursed by the wind, and quito uncheck-
| ed by the rain. 1t was admitted by most
| people present that, if the test was severe
| rs to time. the exposures of the magazines
| TO heat so intense and continuous during
| that time, was test severer still. Shortly
| after four o'clock one of the magazines was
disengaged-no easy task-from the glow
| ing mass around and over it. 1t was then
| opened and its contents were inspected by
| Major Majendie. One of the thermome-
| ters were broken. The other marked 2lO0.
| OF course none of the rods of alloy were
| fused. The "pinches" of loose powder
were thoroughly wetled, and the paper con-
tanning them was pulp. The powder in
the eanisters came forth unframed, and its
| properties were unchanged, portions taken
| from each canister exploding readily when
a spark was applied. The magazine had
been sorely tried. In two places the flames
| had eaten holes through the exterior plate
\ of iron into the first chamber. The outer
plate of the door had also slightly bulged,
partly, perhaps from expansion, partly ow-
| ing TO the pressure from within-the gen.
Grated vapor seeking an outlet. But all
| admitted that the magazine had passed sue
| cesslully through the fire, and had fulfilled
| the promise of its makers that il would not
merely, during the stipulated time, resist
| fire but preserve its contents from explo-
SION. The other furnaces were left to burn
out, TO be examined the followin day.
| Mechanics Magazine, London.
The foregoing article will give the reader
| an idea of the fire-ressting qualities of al
| UNI when combined with sawdust even-a
very poor non-conductor of heat, and as
our safes are filled with alum and dry plas-
| ter OF Pars-the latter the best non-con-
ductor of heat known, there can be no
| question as to their fireproof qualities.
The alum melts only when subjected to
an intense heat, and the plaster then alb
serbs and holds the moisture Ion ger than
sawdust or any other substance can, and
prevents it from escaping too rapidly.
| MARVIN Il Co.,
265 Broadway, New York 72l Chestnut
| St., Philadelphia; l0S Bank St., Cleve-
land, Ohio.
A. IL. Keith, special agent for New Eng
! land and Northern New York.