IMPROVEMENTS IN THE MANUFACTURE OF EXPLOSIVE COMPOUNDS
Year: 1863

page_text: LETTERS PATENT to Julian John Révy, of No. 28, Grosvenor Street,
Eaton Square, Civil Engineer, for the Invention of "IMPROVEMENTS IN
THE MANUFACTURE OF EXPLOSIVE COMPOUNDS."
Sealed the 26th April 1864, and dated the 3rd November 1863.
PROVISIONAL SPECIFICATION left by the said Julian John Révy at the
Office of the Commissioners of Patents, with his Petition, on the 3rd
November 1863.
I, JULIAN JOHN REVY, of No. 28, Grosvenor Street, Eaton Square, Civil
Engineer, do hereby declare the nature of the Invention for "IMPROVEMENTS
IN THE MANUFACTURE OF EXPLOSIVE COMPOUNDS," to be as follows:-
In the Specification of a Patent granted to Thomas Wood Gray, dated the
15th April 1862 (N° 1090), there is described a process for manufacturing
explosive compounds. This process, which was communicated to the
patentee by myself, produces explosive compounds of more uniform quality
than had theretofore been produced, but the process described is costly, using
a great deal of acid, and the results are not so uniform as I have since been
able to obtain.

page_text: The object of my present Invention is then to obtain more uniform results
than can be obtained by working according to the Specification of the said
former Patent, and also greatly to reduce the cost of the process. In the
first place, in preparing the cotton I find that if it be only washed in water
and dried as heretofore, uniform results are not obtained, for the cotton as it
comes from the spinning or twisting process is frequently greasy, and the
grease is not removed by merely washing in water; I therefore first wash
the cotton in a weak solution of potash or other alkali; and then complete the
washing with water, as before.
In the converting process I proceed as follows:-I steep the prepared cotton
yarn, thoroughly dried and in the form of bundles of lightly twisted yarn, in
an acid mixture, using the apparatus represented in Figures 1, 2, 3. I use, by
preference, one part by weight of nitric acid, specific gravity 1-485, and three
parts by weight of sulphuric acid, specific gravity 1-84, the acids being pure
and thoroughly mixed together.
The apparatus consists of two cast-iron tanks T', T2, the inner tank T¹ being
kept cool during the process by a constant flow of cold water H, which is
maintained through the outer vessel; the water enters at M and leaves at N.
The inner tank T¹ is divided into three compartments; E contains the store
of acid mixture; F, the acid mixture in which the process of steeping is
performed; and I represents the compartment with the pot to receive the
steeped cotton. Two or other convenient number of skeins of cotton yarn of
about 3 to 4 ounces in weight, thoroughly dessicated, are immersed at one
operation in the acid mixture contained in F, a spatula being used to effect
complete saturation of the cotton with the acids. The cotton is next removed
from the bath, laid upon the perforated shelf I, and by means of a spatula
pressed to such an extent that the amount of mixed acid left absorbed by the
cotton may be in the ratio of about 1 weight of cotton to 10 weights of acid
mixture. This a practiced workman does as nearly as his judgment admits.
The cotton skeins are next placed in the pot I, which is filled by repeated
operations, and after each dipping the portion of acid absorbed is made good
by taking acid from the compartment E, and putting it into the compartment
F; this is done by means of a spoon capable of containing just the measure of
acid which should be used at each dipping operation; in this manner the
surface of the acid in F should be always maintained at the same level O, P.
The vessel I being filled in the above manner, the cotton yarn is next
compressed by a loosely fitting perforated disc furnished with a handle, in such
manner that the skeins may be wholly covered with the acid mixture soaked
up, to the farther action of which the cotton is left exposed for about

page_text: 48 hours, these pots 9 being cooled during the space of time. In order to
effect the impregnation of gun cotton with soluble glass, as described in the
Specification of the Patent before referred to, I use a centrifugal machine,
the drum of which revolves at a high speed, and is to contain the gun cotton
to be impregnated; a central tube passes into the revolving drum and supplies
the glass solution, the density of which is about 12° Beaumé. The cotton is
afterwards dried by exposure to the atmosphere, the carbonic acid of which
combines with the soda of the water-glass, and the silica is precipitated upon
the gun cotton fibre; the carbonate of soda is got rid of afterwards by washing.
Thus it will be observed that in this process the water-glass is applied in a
cold state, for I have found that when it is used in a boiling state as here-
tofore, less uniform results are obtained.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Juliau John Révy in the Great Seal Patent Office on the
3rd May 1864.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JULIAN
JOHN RÉVY, of No. 28, Grosvenor Street, Eaton Square, Civil Engineer, send
greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Third day of November, in the year of our Lord
One thousand eight hundred and sixty-three, in the twenty-seventh year of Her
reign, did, for Herself, Her heirs and successors, give and grant unto me, the
said Julian John Révy, Her special licence that I, the said Julian John
Révy, my executors, administrators, and assigns, or such others as I, the
said Julian John Révy, my executors, administrators, and assigns, should at
any time agree with, and no others, from time to time and at all times there-
after during the term therein expressed, should and lawfully might make,
use, exercise, and vend, within the United Kingdom of Great Britain and
Ireland, the Channel Islands, and Isle of Man, an Invention for "IMPROVE-
MENTS IN THE MANUFACTURE OF EXPLOSIVE COMPOUNDS," upon the condition (amongst
others) that I, the, said Julian John Révy, my executors or administrators,
by an instrument in writing under my, or their, or one of their hands and
seals, should particularly describe and ascertain the nature of the said
Invention, and in what manner the same was to be performed, and cause

page_text: the same to be filed in the Great Seal Patent Office within six calendar
months next and immediately after the date of the said Letters Patent.
NOW KNOW YE, that I, the said Julian John Révy, do hereby declare
the nature of the said Invention, and in what manner the same is to be per-
formed, to be particularly described and ascertained in and by the following
statement thereof, that is to say:-
In the Specification of a Patent granted to Thomas Wood Gray, dated the
15th April 1862 (No. 1090), there is described a process for manufacturing
explosive compounds. This process, which was communicated to the patentee
by myself, produces explosive compounds of more uniform quality than had
theretofore been produced, but the process described is costly, using a great
deal of acid, and the results are not so uniform as I have since been able
to obtain.
The object of my present Invention is then to obtain more uniform results
than can be obtained by working according to the Specification of the said
former Patent, and also greatly to reduce the cost of the process.
In the first
place, in preparing the cotton I find that if it be only washed in water and
dried, as heretofore, perfectly uniform results are not obtained, for the cotton
as it comes from the spinning or twisting process is frequently greasy, and the
grease is not removed by merely washing in water; I therefore first wash the
cotton in a weak solution of potash or other alkali (say, 3° Beaumé), and
then complete the washing with water, as before.
In the converting process I proceed as follows:-I steep the prepared
cotton yarn, thoroughly dried and in the form of bundles of lightly twisted
yarn, in an acid mixture, using the apparatus represented in Figures 1, 2, 3.
I use, by preference, one part by weight of nitric acid, specific gravity 1-485,
and three parts by weight of sulphuric acid, specific gravity 1.84, the acids
being pure and thoroughly mixed together conveniently, as described in the
Specification of Gray's Patent before referred to.
The apparatus consists of two cast-iron tanks T1, T2, the inner tank T¹ being
kept cool during the process by a constant flow of cold water H, which is
maintained through the outer vessel; the water enters at m and leaves at n;
this is done because the temperature in the dipping tank should never rise
above 80° Fahrenheit, and it should not fall below 40° Fahrenheit. The
inner tank T¹ is divided into three compartments: E contains the store of
acid mixture; F, the acid mixture in which the process of dipping or steeping
is performed; and G, G, represents the compartment with the pot to receive
the steeped cotton. Two or other convenient number of skeins of cotton

page_text: yarn, together of about 3 to 4 ounces in weight, thoroughly desiccated or
containing no trace of moisture, are immersed at one operation in the acid
mixture contained in F; an iron spatula being used to effect complete
saturation of the cotton with the acids, this will be effected in about one
minute. The cotton is next removed from the bath. laid upon the perforated
shelf I, and by means of a spatula pressed to such an extent that the amount
of mixed acid left absorbed by the cotton may be in the ratio of about 1
weight of cotton to 10% weight of acid mixture; this a practised workman
does as nearly as his judgment admits. The cotton skeins are next placed
in the pot G, which is filled by repeated operations, and after each dipping the
portion of acid absorbed is made good by taking acid from the compart-
ment E, and putting it into the compartment F; this is done by means of a
spoon capable of containing just the measure of acid which should be used at
each dipping operation; in this manner the surface of the acid in F should
be always maintained at the same level o, p. The pots G should of the best
earthenware; they are not filled more than two-thirds full, and they contain
one pound of cotton and 10 pounds of acid; each pot as it is filled is
weighed, and the amount of acid is accurately adjusted. The pot being filled
in the above manuer, the cotton yarn is next compressed by a loosely fitting
perforated disc furnished with a handle, in such manner that the skeins may
be wholly covered with the acid mixture soaked up, to the further action of
which the cotton is left exposed for about 48 hours; during this space of time
the pots G are covered and are kept cool; they are for this purpose immersed in
a trough of water, through which a constant flow is maintained; the temperature
in the pots should be kept within the limits above given for the dipping vessel.
If, notwithstanding the precautions, a pot should heat and commence to fume,
as will happen if water get into the pot, or if the dipping be improperly con-
ducted, the pot is removed and its contents rejected. Considerable precaution
is necessary to prevent the cotton re-absorbing moisture after it has been
dried and before dipping, as a very short exposure is sufficient to allow the
cotton to absorb enough moisture to render it unsuitable for use.
cotton comes out of the pots G it is conveniently treated in the manner
described in the Specification of Gray's Patent, before referred to, until
arriving at the process of saturating with soluble glass. Artificial ventilation
is found to be necessary over thé dipping trough, and also over the centrifugal
machine for separating the acid from the cotton after it comes out of the
pots G. In order to effect the impregnation of gun cotton with soluble or
water-glass I employ a centrifugal machine; the gauze drum is lined with a
When the

page_text: cloth, and the skeins of cotton, thoroughly saturated with water-glass solution,
are built up around the interior of the drum, so as to form as it were a
circular wall within it, say, 3 or 4 inches thick, then an inner cylinder
or frame is dropped into the drum to keep the skeins in their places, and the
drum is then filled with water-glass solution; the drum is now rotated com-
paratively slowly, so as to keep up a steady flow through the cotton, the drum
being, however, kept full by constantly admitting more solution; in this
way the work goes on for 2 or 3 minutes, when the admission of water-glass
solution is stopped, and the speed of the drum is increased until ultimately
with a 30-inch drum a speed of 1,200 revolutions per minute is obtained.
The cotton which is then nearly dry is taken out, and the skeins are hung
up on rods in an open drying shed. The strength of water-glass solution
which I employ is about 12° Beaumé, and the temperature should be about
82° Fahrenheit. The water-glass solution may be used several times; so long
as it remains clear it should be protected from the air. The cotton remains
in the drying sheds for several days, and by exposure to the atmosphere
carbonic acid combines with the soda of the water-glass, and the silica is
precipitated upon the gun cotton fibre; the carbonate of soda is got rid of
afterwards by careful and continued washing in running water.
be observed that in the process the water-glass is applied in a nearly cold
state, for I have found that when it is used in a boiling state, as heretofore,
less uniform results are obtained. The final cleansing of the cotton from any
dirt it may have contracted in the process is effected with soap and water;
afterwards it is rinsed and dried in the air; the drying-house is warmed in
bad weather.
Thus it will
Having thus described the nature of my said Invention, and the manner of
performing the same, I would have it understood that what I claim is,-
First, the preparing the cotton for use in the manufacture of gun cotton by
washing it in an alkaline solution.
Second, the process of dipping or steeping the cotton, as herein-before set
forth, small and regular quantities of the cotton being dipped one after the
other in a dipping vessel containing a considerable quantity of acid, the
contents of which are after each operation brought back to the proper strength
by the addition of fresh acid to compensate for that removed by the portion of
cotton last dipped.
Third, the general arrangement of the apparatus herein-before described and
shown in the annexed Drawings.
Fourth, the treating gun cotton with water-glass by means of a centrifugal
machine, as herein-before described.

page_text: Fifth, the employment for treating gun cotton of water-glass solution in a
cool in place of in a boiling state, as heretofore.
In witness whereof, I, the said Julian John Révy, have hereunto set
my hand and seal, this Third day of May, in the year of our Lord One
thousand eight hundred and sixty-four.
JULIAN JOHN RÉVY. (L.S.)