Burlington weekly free press. [volume] (Burlington, Vt.) 1866-1928, 1873-09-12
Important Tests of Fireproof safes. by
the English Governments.


From The Mechanics Magazine, london.
"some experiments as to the storage Of gunpowder
have been recently tried at the Practice Range,
Plumstcad Marshes, at the instance of the Home
Secretary and by permission Of the Secretary Of
State for War With a view to guard against the
danger of explosion Messrs Miner d Co. Of Liver
pool have designed firePrOof safe, to hold small
Quantities of gunpowder. and the experiments were
made to determine how far these miniature maya
zines will preserve their contents from explosion
when exposed to the action OF fire.
Four ma gaines were put to the proof. In form
they differ in respect from any ordinary ireprooi
safe They are formed of four inch chambers be-
tween each of which is stuiline of alum and saw
dust The action Of heat dissolyes the alum, which
contains 81 per cent OF water ana the liquid portion
finds its way through small holes in the safe wet
ting any loose powder, while that contained in
canisters is so protected as TO be non-explosive.
This at least 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 inter
nal diameter, and each heaped up with wood, shay
ings, coal, and q dash oil petroleum TO assist L.
milton, All the magazines were OF the same size,
and made 70 hold one hundred pounds Of powder,
loose or in canisters, as il Is generally kept by
tail dealers and sporsmen; but for the purpose OF
experiment, only 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 & ZamDra's selfregistering Their
mometers with p little sticks of alloy, tin and
lead) so made under Professor Abels directions as
II.
alloy at varying degrees of TEN perature from 10
to 55S Fair. ounpowder explodes at a tempera-
ture OF 500 but long before this degree of heat
was reached, it was expected that the sulphur
would be yolatilized, when the remaining constitu.
ants would be robbed Of their chief powers fol
mischief.
BY a. m, all four furnaces were in a blaze
and there could be doubt as TO the rough reality
OF the ordeal which the magazines were undergoing
As the wa II of coal gradually burnt through anc
| the flames rose high above the buried magazines
there seemed to be nowish among any visitors to dis
obey the earnest request addressed to them, not
approach the furnaces during tine progress OF tn,
| experiments. There was little, indeed, to temp
| visitors from cover. The rain poured down inces
| sanity during the greater part Of the day, AMI
| Plumstead Marshes at no time very lively, becami
| a dismal swamp indeed. Meanwhile the fire
burned furiously, nursed by the wind, and quit,
unchecked by the rain. 1t was admitted by mos
people present that, If the test was severe as {,
tms, the exposure OF the magazines to heat s.
i, tense and continuous during that time was a ties
sew ,rer still Shortly after four O'Clock one of tn
ma ga zines was disengaged-no easy task-from tn,
-Iawiu 2 mass around and 1t. IL was thel
9nened. and its contents were inspected by Majo
MsIeudie One OF the thermometers was broken
rhs other marked 2luo. Of course none OF the rod
AZ ALLOW were fused. The "pinchesr OF loose pow
der we're thoroughly wetted and the paper contain