118 
PROTECTED GUN POWDER. 
It requires only to be seen how'larger machinery for the sifting of the powder and 
restoring it to its original state, may he constructed so as to be easily used in a sudden 
emergency. For, though the advantages which the invention offers to the use of powder 
at home are sufficiently great, it is necessary to its adoption by the army and navy that 
its mechanical appliance should be of the swiftest and readiest kind. An objection has 
been raised on the ground that, after the gunpowder had been sifted, some portion of 
the protective powder would adhere to the grains. This is not the case, as has been 
proved by microscopic investigation; though Mr. Gale shows that, though it were the 
case, it would be no objection, as at present the coating of the powder with blacklead, 
while in course of manufacture, gives additional force to the explosion. 
The material which thus renders gunpowder temporarily innocuous is simply glass 
ground down to an exceedingly fine powder; various other 'substances have been tried 
(especially flint, which, however, became too floury and dusty), but no one has been 
found so useful and successful as glass. The cost of it, as we have already stated, is 
80s. per ton, and Mr. Gale is prepared to furnish any quantity of it on the shortest 
notice, as the advertisements say, at that price. It may be used, besides, for a variety 
of purposes: scours copper and other metals into a brilliancy sufficient to make the 
inventor of polishing-paste die of envy. At present Mr. Gale advises three pounds 
of his powder to one of gunpowder as the safest proportion ; but a much smaller pro¬ 
portion renders the gunpowder perfectly non-explosive ; with this difference, however, 
that in equal parts of gunpowder and protective powder the former will burn, though 
it does not explode. A proportion of two to one burns slowly, three to one allows 
a few grains to ignite at hap-hazard, four to one is mere dead material. The rapidity 
with which the powder can be separated is somewhat remarkable; perhaps owing to 
the nature of the material with which it is mixed. The proportions we have men¬ 
tioned are weight, not bulk; protective powder being heavier than the gunpowder, 
what forms a proportion of three to one in weight is only two to one in bulk, and 
this is an important fact in considering storage. Another advantage offered by this 
material is that it keeps the powder perfectly dry, however the mixture may be ex¬ 
posed to the air ; and it is well known that by itself gunpowder rapidly absorbs 
moisture from the atmosphere and becomes for the time useless.— Daily Paper. 
The following letter on “Mr. Gale’s Gunpowder,” which appeared in the ‘Times,’ 
Aug. 4th, from “V. D. M.,” Royal Arsenal, Woolwich, will be read with interest:— 
The account which appeared in your columns on Thursday last of experiments with 
Mr. Gale’s gunpowder, and more especially the closing paragraph of that account, dis¬ 
tinctly convey the idea that the making gunpowder non-explosive on Mr. Gale’s plan is 
original. It may interest your readers to know that the system was not merely “ vaguely 
imagined,” but actually tried oil a large scale, by M. Piobert, the well-known French 
writer on gunpowder, in 1835, and by M. Fadeleff, Professor of Chemistry at St. Peters¬ 
burg, between 1840 and 1844. Some of the results of these researches will be found in 
Piobert’s ‘Traite d’Artillerie, Theorique et Experimentale,’ pages 213 to 220, and in the 
‘ Comptes Reudus ’ of the Academie des Sciences, vol. x. p. 320, and vol. xxiii. p. 1148. 
Nor is it a fact that the substances used for this purpose were, “by their ready absorp¬ 
tion of damp, entirely unsuited for the end in view.” Sand, it is true, was used by Pio¬ 
bert, but sand in a pure state. The silica of the laboratory is not an absorbent body ; 
while it would probably be found by experience that finely powdered glass would be¬ 
come absorbent, since it is well known that glass does become alkaline in course of 
time. But Piobert used other substances, which he preferred, partly because the gritty 
nature of sand presented an element of danger. He found that any of the consti¬ 
tuents of gunpowder finely ground met the required end, and of the three he pre¬ 
ferred saltpetre, as being the one which gave experimentally the best results. M. Fa- 
deieff tried a variety of substances, and ultimately gave the priority to a mixture of 
wood charcoal and mineral charcoal (graphite); and among other advantages of this 
“ carbo-graphite ” he claims for it that of being unaffected by moisture. (“Z« presence 
de Vhumidite rialtere en rien ses proprietes .”) So much for the substances employed. 
; Let us now see if the principle of M. Piobert’s plan was the same as that of the plan 
now advocated by Mr. Gale. It is necessary here to explain briefly the action of fired 
gunpowder. 
Gunpowder does not, as is often supposed, explode instantaneously on being ignited; it 
