IMPROVEMENTS IN THE PREPARATION OP DOUGH
Year: 1857

page_text: LETTERS PATENT to John Dauglish, of Great Malvern, in the County of
Worcester, M.D., for the Invention of "IMPROVEMENTS IN THE PREPARATION
OP DOUGH."
Sealed the 26th January 1858, and dated the 21st August 1857.
PROVISIONAL SPECIFICATION left by the said John Dauglish at the
Office of the Commissioners of Patents, with his Petition, on the
21st August 1857.
I, JOHN DAUGLISH, of Great Malvern, in the County of Worcester, M.D.,
do hereby declare the nature of the Invention for "IMPROVEMENTS IN THE
PREPARATION OF DOUGH," to be as follows:-.
It has been proposed to employ carbonic acid gas under pressure in
impregnating water used for mixing flour or meal to form dough, and it is has
also been proposed to keep the interior of the vessel in which the mixing of
such matters is accomplished under pressure in order to prevent the escape
of gas from the water during the process of mixing by charging the same with
carbonic acid gas. Now, I have discovered that much of the carbonic acid
gas used for keeping the interior of the vessel under pressure may be saved,
and again and again employed in the process.
In using carbonic acid gas for the purpose of keeping the mixing or
kneading vessel under pressure, it is advisable to keep it pure by excluding as
completely as possible atmospheric air or other gas; and in order to accom-
plish this I prefer as the simplest method the introduction of carbonic acid
gas among the materials to displace the air or other gases, allowing them to
escape before closing the vessel completely. When the kneading or mixing

page_text: has been properly accomplished, and it is desirable to release the pressure
from the mixing vessel, instead of releasing the gas into the atmosphere, I
conduct it into another vessel or reservoir in any suitable manner, preferring
to expand it into a gasholder or other suitable vessel by its own elastic force,
or by expanding it into a separate vessel capable of bearing an excess of
pressure until the pressure in both vessels is equalized, and then pumping the
remaining gas from the kneading vessel into the other vessel until a sufficient
quantity has been discharged from the kneading vessel, or by pumping the
entire quantity of gas into a separate vessel or reservoir. It has been
proposed to use a separate vessel in which to charge the water used in mixing
with the necessary quantity of carbonic acid gas before introducing it into
the mixing vessel. Now, I in some instances cause the water to absorb the
necessary quantity of gas and so incorporate it with the dough when it is
within the mixing vessel by putting the flour and other dry material and the
water or liquid material together into the kneading vessel and afterwards putting
on the pressure of gas, and so allowing them to remain until the purpose is
effected, or by putting the dry materials under pressure before introducing the
water, and afterwards forcing the water in a shower through the gas within
the mixer.
In order to increase the expanding or spongy property of the dough made
under pressure of carbonic acid gas, or with water charged with carbonic acid
gas, I introduce into the materials of which it is to be composed bicarbonate
of soda or of potash and tartaric or hydrochloric acids, so that by their com-
bination carbonic acid may be given off, and these may be used along with
aerated water or with water not aerated. Also I cause the dough made under
pressure of carbonic acid gas or with water charged with carbonic acid gas to
ferment for the like purpose of imparting to it extra spongy or desicular
properties, and for this purpose I add to the flour, meal, or other material of
which the dough is to be composed certain proportions of leaven, yeast, or
other body or bodies capable of inducing fermentation.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said John Dauglish in the Great Seal Patent Office on the
20th February 1858.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JOHN
DAUGLISH, of Great Malvern, in the County of Worcester, M.D., send 35
greeting.

page_text: WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Twenty-first day of August, in the year of our Lord
One thousand eight hundred and fifty-seven, in the twenty-first year of Her
reign, did, for Herself, Her heirs and successors, give and grant unto me, the
said John Dauglish, Her special licence that I, the said John Dauglish, my
executors, administrators, and assigns, or such others as I, the said John
Dauglish, my executors, administrators, and assigns, should at any time agree
with, and no others, from time to time and at all times thereafter 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 "IMPROVEMENTS IN THE PREPARATION
OF DOUGH," upon the condition (amongst others) that I, the said John
Dauglish, 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 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 John Dauglish, 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:-
It has been proposed to employ carbonic acid gas under pressure in
impregnating water used for mixing flour or meal to form dough, and it has
also been proposed to keep the interior of the vessel in which the mixing of
such matters is accomplished under pressure in order to prevent the escape
of gas from the water during the process of mixing by charging the same with
carbonic acid gas. Now, I have discovered that much of the carbonic acid
gas used for keeping the interior of the vessel under pressure may be saved,
and again and again employed in the process.
In using carbonic acid gas for the purpose of keeping the mixing or
kneading vessel under pressure it is desirable to keep it pure by excluding as
completely as possible atmospheric air or other gas; and in order to accom-
plish this I prefer as the simplest method the introduction of carbonic acid
gas among the materials to displace the air or other gases, allowing them to
escape before closing the vessel completely. When the kneading or mixing
has been properly accomplished, and it is desirable to release the pressure
from the mixing vessel, instead of releasing the gas into the atmosphere I
conduct it into another vessel or reservoir in any suitable manner, preferring

page_text: to expand it into a gasholder or other suitable vessel by its own elastic force,
or by expanding it into a separate vessel capable of bearing an excess of
pressure until the pressure in both vessels is equalized, and then pumping the
remaining gas from the kneading vessel into the other vessel until a sufficient
quantity has been discharged from the kneading vessel, or by pumping the
entire quantity of gas into a separate vessel or reservoir. It has been
proposed to use a separate vessel in which to charge the water used in mixing
with the necessary quantity of carbonic acid gas before introducing it into
the mixing vessel. Now, I in some instances cause the water to absorb the
necessary quantity of gas, and so incorporate it with the dough when it is
within the mixing vessel by putting the flour and other dry material and the
water or liquid material together into the kneading vessel and afterwards
putting on the pressure of gas, and so allowing them to remain until the
purpose is effected, or by putting the dry materials under pressure before
introducing the water, and afterwards forcing the water in a shower through
the gas within the mixer.
In order to increase the expanding or spongy property of the dough made
under pressure of carbonic acid gas, or with water charged with carbonic acid
gas, I introduce into the materials of which it is to be composed bicarbonate of
soda or of potash, and tartaric or hydrochloric acids, so that by their combina-
tion carbonic acid may be given off, and these may be used along with æerated
water, or with water not ærated. Also I cause the dough made under pressure
of carbonic acid gas, or with water charged with carbonic acid gas to ferment,
for the like purpose of imparting to it extra spongy or desicular properties, and
for this purpose I add to the flour, meal, or other material of which the dough
is to be composed, certain proportions of leaven, yeast, or other body or bodies.
capable of inducing fermentation.
Having thus stated the nature of my said Invention, I will proceed more.
fully to describe the manner of performing the same.
Figure 1 is
DESCRIPTION OF THE DRAWINGS.
side elevation of the apparatus used in carrying out my
Invention. A, A, is the mixing vessel; it consists of a strong globular or
spheroidal vessel; it is mounted and fixed on a suitable framing B, B, it is
furnished with a man-hole C at the top, with a suitable cover and means of
fastening it, so as to render it air-tight, and at the bottom there is another
opening of a similar size, which is closed by a slide D (or it may be closed
by any other suitable method). Figure 2 is a front elevation in section of
this spheroidal vessel. Through this vessel, at the stuffing boxes E, E, a

page_text: sbaft or spindle F passes, and on this shaft are fixed the arms or agitators
fffff; short arms are also fixed at the back of the mixing vessel at right
angles to the axis F, in the spaces between which the arms or agitators
fffff, pass, by which means the operation of mixing or kneading is
facilitated. The spindle F instead of being made straight, may be made of the
form of a ring or oval, as shown in dotted lines in Figure 2, in order to
prevent the dough from winding round the centre, where there will be scarcely
any movement. To one end of the shaft F the toothed wheel G is fixed, and
motion is given to this wheel by a smaller toothed wheel, which again receives
its motion from a steam engine or other motive power, by the drum H fixed
on the same shaft with it. This vessel and apparatus are similar to what were
described in the Specification of my former Patent. I is a set of force pumps,
the barrels and valves of which are surrounded by a cistern of cold water, for
the purpose of keeping them cool, as described in my said former Specification;
K is a gas holder; L is a copper vessel furnished with a glass water guage, and
connected at the bottom with the mixing vessel A, by the pipe a and the stop-
cock b, and at the top with the mixing vessel by the pipe c and stop-cock d;
a pressure guage is attached to the pipe c above and below the stop-cock d, so
as to indicate the pressure of gas used. The pipe e, e, connects the pumps I
to the vessel L, and it terminates within that vessel by a valve and a rose.
From the pipe e, e, a small pipe g, furnished with a stop-cock, passes to the
bottom of the mixing vessel A. The pipe k, k, communicates with the mixing
vessel A by the stop-cock at one end, and with the gasholder K at the other
end. The apparatus is worked in the following manner :-Having drawn into
the vessel L the proper quantity of water by the cock m, and placed within
the mixing vessel A the flour or other dry material, I proceed to remove from
such flour or dry material all atmospheric air, and also injurious or unsuitable
gas that may have been produced by the decomposition of the bread stuff, or
otherwise mixed therewith. This I do by leaving the man-hole C open, and
by forcing through the pipe g carbonic acid gas, pumped or otherwise permitted
to flow from the gasholder K, until the air or unsuitable gas has been expelled
at the opening C. The method of expelling of air or unsuitable gases from
the flour or other dry material may be varied. When this has been accom-
plished, and the mixing vessel closed air-tight, the pumps I are set to work,
and they pump carbonic acid gas from the gasholder K (which I prefer
to be made of wood, though other material may be employed,) through the
pipe e, e, into the vessel L, the gas will rise through the water therein to the
top, and passing down the pipe c will enter the mixing vessel A. The pumping
is continued until a sufficient pressure has been obtained in the vessel L and

page_text: mixing vessel A, which will be ascertained by the pressure guage.
I would
state that the degree of pressure in the mixing vessel may be greatly varied
according to the degree of lightness desired to be obtained to the bread,
biscuit, or other articles made from the dough in making very light bread. I
have used a pressure as high as 200 lbs. to the square inch; whilst in making
dough for other articles I have used a pressure only a few lbs. above the
atmosphere. The water absorbs the gas during the process of pumping, and
will be ready to be drawn into the mixing vessel by opening the stop-cock b, and,
the stop-cock d being also open, gas will rise through the pipe c into the
vessel L, and the water will pass into the mixing vessel A; the mixing arms
are set going until the dough is properly prepared. When this is accomplished,
the stop-cock is opened, and the gas is allowed to pass back through the
pipe k into the gasholder K, there to be retained for farther use.
The dough
is then discharged from the mixing vessel to be prepared for the oven.
I would have it understood that I do not confine myself to the use of any
particular form of gasholder to receive the gas from the mixing vessel. I can,
when it is desirable, receive the gas from the mixing vessel into a vessel
which is capable of bearing an excess of pressure, and when the pressure has
become equal between the two vessels, either expand the remainder from the
mixer into a gasholder or pump it from the mixing vessel into the other
vessel, which may also be a mixing vessel; or the whole may be pumped
from one vessel into another. Indeed the method may be greatly varied.
In place of putting water into the vessel L and afterwards drawing it when
properly charged with carbonic acid into the mixing vessel, the water can be
introduced into the mixing vessel A, so as to cause it to mix with the flour as
little as possible; and when this is done I proceed to expel or remove the air
or injurious gases and put in pressure of gas and then mix the materials into
dough; or the flour or other dry material can be introduced into the mixing
vessel, and when the air has been expelled, and the pressure of gas put on, the
water may be forced by means of a suitable force pump into the mixing
vessel through a rose, so as to cause the water to fall in a shower through the
gas on to the flour, after or during which process the mixing may be accom-.
plished. In the above description I have used the word "water" simply for
the fluid employed, but intend that such word should include whatever fluid
may be used, such as milk, milk and water, and flavoring fluids. In order to
increase the expanding or spongy property of the dough made under pressure
of carbonic acid gas or with water charged with carbonic acid gas, I can
when desired introduce into the materials of which it is composed bicarbonate
of soda or of potash, by carefully mixing these substances in quantities

page_text: varying with the degree of effect desired to be obtained with the dry material
placed within the mixing vessel; and when tartaric acid is used to combine
with these carbonates, the proper equivalent of this acid is to be also carefully
mixed with the dry material in the same manner; but when hydrochloric
acid is used, that acid is to be mixed in due equivalent with the water before
being mixed with the dry material into dough. In place of these substances
or along with them, yeast, leaven, or other suitable substances may be mixed
with the flour or other dry material, in order to cause the dough to ferment,
and thus impart to it extra vesicular properties.
I would remark that in practice it has been found advantageous to mix a
small part of the flour with water, and to boil it into a paste before intro-
ducing the same with the other portion of the charge into the mixing vessel;
by such means the gas appears to be retained more securely in the mass
after it comes from the mixing vessel. For this purpose about one per cent.
of the flour of a charge may be so boiled, mixed with six times its weight of
water; when butter or lard or other fatty matter be used it appears to
have a like effect in retaining the gas, and renders the use of boiled flour less
desirable.
Having thus described the nature of my said Invention and the manner of
performing the same, I would have it understood that I make no claim
to any parts of the apparatus or machinery herein described; nor do I
confine myself to the details; but what I claim is the combining machinery
or apparatus for the preparation of dough in closed vessels, under a pressure
of carbonic acid gas, in such manner that the excess of carbonic acid gas
required in the mixing vessel may not be wasted as heretofore after each
operation of mixing, but saved for further use by receiving the excess of gas
from the mixing vessel into a gasholder or other suitable vessel.
In witness whereof, I, the said John Dauglish, have hereunto set my
hand and seal, this Sixteenth day of February, in the year of our
Lord One thousand eight hundred and fifty-eight.
Witness,
.GEO. PITT.
JOHN DAUGLISH, M.D... (L.S.)