A NEW OR IMPROVED BLASTING POWDER
Year: 1877

page_text: LETTERS PATENT to Raymond Cahuc, of Toulouse, France, but at present of
16, Southampton Buildings, Holborn, in the County of Middlesex, for the
Invention of "A NEW OR IMPROVED BLASTING POWDER."
PROVISIONAL SPECIFICATION left by the said Raymond Cahuc at the Office
of the Commissioners of Patents on the 12th December 1877.
RAYMOND CAHUC, of Toulouse, France, but at present of 16, Southampton
Buildings, Holborn, in the County of Middlesex. "A NEW OR IMPROVED BLASTING
POWDER."
This Invention relates to a new or improved blasting powder.
According to my Invention I combine the following substances or materials in
or about the proportions named.-In one hundred equal parts by weight I take
forty-eight to seventy parts of nitrate of potash, or other equivalent salt, the
quantity being regulated according to the strength of powder required. Eight to
16 parts of sulphur, according to the quality and the rapidity of oxplosive power
desired in the powder. Three to five parts of lampblack, or instead of the lamp-
black, 3 to 9 parts of soot. Soot from wood is preferable to that from coal, and
lampblack is preferable to soot. The quantity is regulated according to the strength
and rapidity of explosion required. The remainder of the hundred parts are made
up of spent tan (if containing refuse animal matter preferred), or sawdust, or the
two combined in any proportions. The spent tan is preferred, but whichever is
used it should be well dried before being used. The above ingredients are finely
ground and then mixed together in a boiler, and moistened to a consistency of a
stiff paste with water in which has been previously dissolved sulphate of iron to
the extent of from 1 to 5 per cent. by weight of the other ingredients or substances,
the proportion being regulated according to the purity of the soot and tan or saw-
dust. The mixture is then subjected to a heat of from 120° to 130° (Rem.), under
which the whole first liquifies and then afterwards solidifies. Whilst subjected to

page_text: this heat the mass should be constantly stirred with a wooden instrument, especially
whilst settling, otherwise the whole may harden into a lump, but if stirred will
assume the form of powder. On this stage being reached the whole is removed
from the fire and subject to a lower heat, sufficient to dry, say, about 50° (Rem.).
The compound is then ready for use, and may be stored and transported with the
utmost safety, as it will not explode unless confined and compressed.
To obtain the full results and benefits of the powder it should be well compressed
before being exploded. It may be exploded by the means ordinarily employed for
firing black powder.
The boiler in which the mixture is heated should be much larger than necessary
to hold the ingredients before being heated, as on being subjected to the heat it
increases greatly in bulk.
For many purposes my compound may be profitably employed combined with
nitro-glycerine, kerosine, or other similar explosive oils or substances, as for
example for torpedoes and stone quarrying, and works under water. The com-
bined product is not inexplosive, as is my product alone, but the mixture is only
mado at the moment when it is to be used, thus reducing the danger to the
minimum.
A good proportion for a good serviceable compound is about 15 to 25 per cent.
of nitro-glycerine or the other explosive employed, the remainder being my
improved powder, but of course the proportions must necessarily vary according to
the strength of explosive required.
The mixture may be effected either in the borehole or previously in a wooden
vessel.
The tamping must be carefully effected in the usual manner.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Raymond Cahuc in the Great Seal Patent Office on the 12th June
1878.
RAYMOND CARUC, of Toulouse, France, but at present of 16, Southampton
Buildings, Holborn, in the County of Middlesex. "A NEW OR IMPROVED
BLASTING POWDER."
This Invention relates to a new or improved blasting powder, and consists
mainly of improvements on an Invention for which Letters Patent, dated 14th
November 1874, and numbered 3934, were granted to John William Gray, to
whom the Invention was communicated by myself and Louis Soulages.
According to my present Invention I employ a smaller proportion of lampblack
or soot than is stated in the Specification of the said former Patent, as I have found
that I can do so with advantage, the compound being safer both in the process of
manufacture and in use, whilst with the somewhat altered proportions of the other
ingredients given it is quite as powerful when exploded_
My new or improved powder is made as follows:-In one hundred equal parts
by weight I take forty-eight to seventy parts of nitrate of potash, or other
equivalent salt, the quantity being regulated acccording to the strength of powder
required. Eight to sixteen parts of sulphur, according to the quality and the
rapidity of explosive power desired in the powder. Three to five parts of lamp
black or soot, soot from wood is preferable to that from coal, and lampblack is
preferable to soot. The quantity is regulated according to the strength and
rapidity of explosion required. The remainder of the hundred parts are made up
of spent tan (if containing refuse animal matter preferred), or sawdust, or the two
combined in any proportions. The spent tan is preferred, but whichever is used it
should be well dried before being employed The above ingredients are finely ground
and then mixed together in a boiler, and moistened to a consistency of a stiff paste
with water in which has been previously dissolved sulphate of iron to the extent
of from 1 to 5 per cent. by weight of the other ingredients or substances, the
quantity being regulated according to the purity of the soot or lampblack and the
tan or sawdust, the smaller quantity only being necessary with purity of the other
ingredients. The mixture is then subjected to a heat of from 120° to 130° (Rem.),
under which the whole first liquifies and afterwards solidifies. Whilst subjected to
this heat the mass should be constantly stirred with a wooden instrument, especially
whilst settling, otherwise the whole may harden into a lump, but if stirred will
become powder. On this stage being reached the compound is removed from the
fire and subjected to a lower heat sufficient to dry it, say, about 50° (Rem.). The
compound is then ready for use, and may be stored and carried with the utmost
safety, as it will not explode unless confined and compressed.
To obtain the full results and benefits of the powder it should be well compressed
before being exploded. It may be exploded by the means ordinarily employed for
firing ordinary blasting powder.
The boiler in which the mixture is heated should be much larger than necessary
to hold the ingredients whilst cool, as on being subjected to the heat the mixture
increases greatly in bulk.
In practice I have found the following proportions of the before-mentioned
ingredients produce the best powder for the respective purposes named:-For the
blasting of hard material offering great resistance I use, of saltpetro, seventy parts;
sulphur, twelve parts; lampblack, five parts; tan or sawdust (well dried), thirteen
parts; and sulphate of iron two parts. For substances offering less resistance and
for coal getting I use, of saltpetre sixty-four parts; sulphur, thirteen parts; lamp-
black, four parts; spent tan or sawdust, nineteen parts; and sulphate of ion, three
parts. For bituminous coal and gypsum quarries, and such like materials, I use of
saltpetre fifty-six parts; sulphur, fourteen parts; lampblack, three parts; tan or
sawdust, twenty-seven parts; and sulphate of iron, five parts.

page_text: For many purposes my compound may be profitably employed combined with
nitro-glycerine, kerosine, or other similar- explosive oils or substances; or, as for
example, for torpedoes and stone quarrying, and works under water. The com-
bined product is not inexplosive, as is my product alone, but the mixture is only
made at the moment when it is to be used, thus reducing the danger to a
minimum.
A good proportion for a good serviceable compound is almost 15 to 25 per cent.
of nitro-glycerine or the other explosive employed, the remainder being my
improved powder; but of course the proportions must necessarily vary according
to the strength of explosion required.
The mixture may be effected either in the borehole or previously in a wooden
vessel.
The tamping must be carefully effected in the usual manner.
In witness whereof, I, the said Raymond Cahuc, have hereunto set my hand
and soal, this Twelfth day of June, in the year of our Lord One thousand
eight hundred and seventy-eight.
Witness,
JOHN W. GRAY, C.E.,
Consulting Engineer & Patent Agent,
16, Southampton Buildings, W.C.
RAYMOND CAHUC. (L.S.)