IMPROVEMENTS IN PROVISIONAL SPECIFICATION
Year: 1864

page_text: LETTERS PATENT to William Augustus Guy, of 26, Gordon Street,
Gordon Square, London, Edmund Edwards, of 1, York Buildings,
Adelphi, London, and Richard Waugh MacArthur, of 56, York Terrace,
Regent's Park, London, for the Invention of "IMPROVEMENTS IN
PROVISIONAL SPECIFICATION left by the said William Augustus Guy,
Edmund Edwards, and Richard Waugh MacArthur at the Office of
the Commissioners of Patents, with their Petition, on the 24th June
1864.
We, WILLIAM AUGUSTUS GUY, of 26, Gordon Street, Gordon Square,
London, EDMUND EDWARDS, of 1, York Buildings, Adelphi, London, and
RICHARD WAUGH MACARTHUR, of 56, York Terrace, Regent's Park, London,
do hereby declare the nature of the said Invention for "IMPROVEMENTS
IN MACHINERY OR APPARATUS FOR THE MANUFACTURE OF BREAD," to be as
follows:-
This Invention consists in mixing the materials for making bread, cakes, or
biscuits with carbonic acid or other suitable gas or vapour, either by aerating
under the ordinary atmospheric pressure, or under greater pressure, the water
with which such materials are mixed, or by generating the carbonic acid or
other gas or vapour in the dough, by the addition of substances which by

page_text: their chemical reaction may generate such gas or vapour, or by the ordinary
process of fermentation, or by a combination of some or all of these methods.
The dough thus aerated is made in ordinary troughs or other suitable vessels,
and when the materials are sufficiently incorporated it is cut into pieces of a
size suitable to form one or more loaves of bread, cakes, or biscuits when
baked. And in some cases we cut the dough into pieces thus by hand, but
we prefer to expel it from the vessel in which it is made through an aperture
of proper size either by means of revolving blades or arms or moveable
pistons. And we cut it into pieces as it issues from this aperture either
by hand or by means of knives or cutting wires worked by the same power
which expels the dough from the vessel. Each piece of dough thus cut off
is placed into a mould or upon a plate or tile, and a sufficient number of
these moulds are then placed in or under a receiver, from which the air is
then partially withdrawn by means of an air pump or pumps. The carbonic
acid or other gas in the dough (whether formed by the aeration of the water
with which the dough is mixed, or by generation in the dough, or by fermen-
tation, or by a combination of some or all of these methods) is thus allowed
to expand, and the dough becomes spongy and fit for baking. The partially
exhausted receivers are then placed in a suitable oven, in which the dough is
baked. The air is afterwards re-admitted to them and the bread is removed
finished.
In some cases we make the receiver from which the air is partially
exhausted form a part of the oven, so that the bed or bottom of the receiver
may be immediately over or adjoining the fire by which the oven is heated,
and the moulds containing the dough are placed at once in the oven, from
which the air is then withdrawn.
And in some cases we make the bed of the oven circular, and cause it to
revolve either horizontally or vertically over the fire, so that the moulds con-
taining the bread may be placed in succession upon that part of the circum-
ference of the bed of the oven immediately over the hottest part of the fire,
and may be gradually carried round, so that when the baking is completed
the bread is removed from a comparatively cool part of the oven. And we
make the fire-place or furnace either fixed or moveable.
In some cases we use superheated water or steam instead of the direct
action of fire, to give out the necessary heat for baking the bread. In order
to exhaust the air from the receivers, we either make them with doors which
can be closed air-tight by means of screws or wedges, and attach to them
valves or cocks which can be made to communicate with exhausting air
pumps, or when the receiver forms part of the oven, the upper part is made

page_text: to lift up, so that the moulds containing dough can be placed on the bed of
the oven, over which the cover is then lowered; and the lower edge of the
cover is made to dip when lowered into a recess partially filled with mercury,
fusible metal, or other suitable fluid substance, and the air is then withdrawn
from the receiver by means of air pumps whilst the dough is baked, the
mercury or other fluid substance forming an air-tight joint and preventing
the admission of air into the vacuum. And we attach a cock to the receiver,
by which the air can be partially or entirely re-admitted, or by which water
can be admitted.
Great economy is effected by this Invention in the cost of machinery for
making dough and baking bread, and great economy in the time required,
and improvement in the quality of the bread made is obtained by the use of
the apparatus described for creating a partial vacuum round the dough during
the time it is being baked.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said William Augustus Guy, Edmund Edwards, and Richard
Waugh MacArthur in the Great Seal Patent Office on the 22nd Decem-
ber 1864.
TO ALL TO WHOM THESE PRESENTS SHALL COME, we, WILLIAM
AUGUSTUS GUY, of 26, Gordon Street, Gordon Square, London, EDMUND
EDWARDS, of 1, York Buildings, Adelphi, and RICHARD WAUGH MACARTHUR,
of 56, York Terrace, Regent's Park, London, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Twenty-fourth day of June, in the year of our
Lord One thousand eight hundred and sixty-four, in the twenty-seventh
year of Her reign, did, for Herself, Her heirs and successors, give and
grant unto us, the said William Augustus Guy, Edmund Edwards, and
Richard Waugh MacArthur, Her special licence that we, the said William
Augustus Guy, Edmund Edwards, and Richard Waugh MacArthur, our
executors, administrators, and assigns, or such others as we, the said
William Augustus Guy, Edmund Edwards, and Richard Waugh MacArthur,
our 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 MACHINERY

page_text: OB APPARATUS FOR THE MANUFACTURE OF BREAD," upon the condition (amongst
others) that we, the said William Augustus Guy, Edmund Edwards, and
Richard Waugh MacArthur, our executors or administrators, by an instru-
ment in writing under our, or one of our, 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 we, the said William Augustus Guy, Edmund
Edwards, and Richard Waugh MacArthur, do hereby declare the nature of
our said Invention, and in what manner the same is to be performed, to be
particularly described and ascertained in and by the following statement :-
This Invention consists in arranging one or more vessels of suitable form
and material having openings which can be readily closed air-tight, and through
which flour, salt, and water, or other materials, can be introduced. These
vessels (or vessel) contain mixing apparatus herein-after more particularly
described, so arranged that it can be caused to revolve by any convenient
power, which may also drive forcing pumps by which carbonic acid or other
gas may be forced into the vessels by means of the apparatus to be described.
This carbonic acid or other gas may be generated in any convenient way and
stored in a gasholder, whence it is pumped when required, or it may be
generated under very high pressure in suitable vessels, whence it may be
allowed to escape directly into the mixing vessels without pumping, and these
generating vessels may be made fixed or moveable, or the carbonic acid gas
may be generated from muriatic acid and carbonate of soda in such proportions
that the resulting compound may be common salt, which may be used in
mixing the dough. One or more of these mixing vessels are so arranged that
when one of them has been partially filled with flour, salt, and water (or other
materials for making dough for bread) the mixing apparatus to be described
can be caused to revolve and thus to combine the several ingredients into
dough. Whilst the mixing apparatus is working (or previous to or subsequent
to its working) carbonic acid or other gas generated in any suitable manner is
allowed to pass or is forced into the vessel. The ingredients in the vessel are
thus converted into dough strongly impregnated with gas. All these operations,
that is to say, the mixing of the dough and impregnation with gas, are carried
on simultaneously and in the same vessel. At the bottom of each vessel is a
discharging aperture, having a cock or valve of a suitable kind, but which we
prefer of the form herein-after described, from which the dough may be
measured and discharged by the pressure of the gas above it. Whilst the

page_text: vessel has thus been emptied of dough and retains only gas at a high pressure,
another vessel (where we use more than one) has been charged with flour,
salt and water, and closed air-tight; a pipe is then opened by which a com-
munication is made between the two vessels, and part of the gas flows from
the emptied to the full vessel. This pipe is then closed and sufficient
additional gas at high pressure is introduced into the full vessel, and its
mixing apparatus is set at work. The gas remaining in the emptied vessel
is either allowed to escape to the gasholder, where one is used, and subse-
quently pumped back by the apparatus to be described when the vessel has
been refilled with the ingredients for dough, or it is saved and again used by
means of the hydraulic cylinder and pumping apparatus herein-after described.
And in some cases we allow the surplus carbonic acid gas to escape through
a pipe into a cistern containing liquor ammoniæ or other suitable substance,
by which it is absorbed, and which may be afterwards utilized in making
bread or in any suitable way. The cock or discharging valve attached to the
mixing vessels is more particularly described and illustrated herein-after, and
is so arranged that the dough is measured into pieces of the size required as it
is discharged from the mixing vessel.
Having thus stated the nature of our said Invention, we will proceed more
fully to describe the same. The accompanying Sheet of Drawings contain
Figures exhibiting some of the forms and arrangements which we give to
apparatus constructed according to our Invention.
Where bread has been made with water aërated with carbonic acid gas
under pressure, it has heretofore been proposed that the flour used for making
the bread should be put under a pressure of air or gas as great or greater
than that under which the water is aërated before the water is admitted to
the flour, in order that the escape of the gas from the water may thus be
prevented. Now we find it to be much more economical in the cost of the
apparatus and in the time required to make dough to mix the flour, water,
and carbonic acid or other gas in the same vessel and at the same time. This
we do by placing the flour, salt and water, and other materials in a strong
vessel, into which the gas is admitted under pressure from a generator whilst
the dough is being mixed by the revolution of suitable arms, and the dough
thus becomes aërated, and sometimes instead of admitting the gas direct from
the generator we pump it from a gasholder or from another vessel where it
is kept under lower pressure. It has been proposed to save the surplus gas
in the mixing vessel by allowing it to return to a gasholder before the dis-
charge of the dough. Now in such case the expulsive power of the gas is not
available, and the expansion of the dough or the removal of pressure would

page_text: tend to choke the pipes; we prefer to expel the dough first, and afterwards to
save the remaining gas. And where we admit gas direct from a generator at
high pressure, we save the surplus gas which remains in the mixing vessel
after the dough has been expelled by allowing it to expand into a vessel of
sufficient size to reduce its pressure to that of the atmosphere, and when the
mixing vessel has been opened and a fresh charge of materials has been
introduced we force back the gas into the mixing vessel by means of the
pumping apparatus shown in the Drawing (or by ordinary pumps), and then
admit from the generator the remainder of the gas required.
By this Invention we are able to use apparatus of a small size and cost,
which may be worked entirely by hand and without the necessity of steam or
other power, and are thus enabled to introduce the use of bread aërated
with carbonic acid gas (the advantages of which have for more than
thirty years been known) into localities where it would otherwise be un-
available.
Figure 1 is a longitudinal section of one form of the apparatus used in
carrying out our Invention. A is a mixing vessel of metal, earthenware,
glass, or other material of sufficient strength, which we prefer of spherical
shape; B is an axis passing through this vessel and working in a stuffing
box. To this is attached mixing apparatus, which we prefer of the shape
shewn in Figure 2. It consists of a ring of slightly less diameter than the
interior of the vessel, to which are attached bars parallel or inclined to the
axis, and at different distances from it on either side, and sometimes we use
no axis, but we make a pin at one side of the ring (as shewn in Figure 3),
which works in a recess in the mixing vessel, and a square hole at the other
side of the ring receives the end of the driving shaft, which is only long enough
for the purpose. In order to obtain ready access to the mixing apparatus,
the vessel is made in two parts, the upper one of which is bolted to the lower
one and can readily be unscrewed and removed without disturbing the re-
mainder of the apparatus. In the small apparatus which we work by hand
we place a handle upon the axis, by which the mixing can be commenced, and
when the dough becomes stiff the handle is removed to the axis of a pinion C,
working into a larger wheel D, by which increased power is gained. The
mixing apparatus may, however, be driven by any convenient power. An
opening E in the upper part of the vessel is closed air-tight by a cover and a
lever and screw, shewn at F.
The carbonic acid gas may be generated in the following way:-H, Figure
1, is a strong vessel lined with lead or earthenware in which the gas is
generated; water and chalk and sulphuric or other acid in proper proportions

page_text: are mixed in this vessel by means of agitators worked by the handle I, and
sufficient gas is thus generated at a high pressure, which can be admitted to
the mixing vessel A whilst the dough is being mixed. In order to replenish
the generator, we either place the chalk and water and the dilute acid in
closed vessels above it, the lower part of which can be made to communicate
by cocks with the generator and the upper part also (after the openings by
which the materials are introduced have been closed), so that the pressure
being equalized the materials flow into it, whilst those already used can be
discharged by a cock at the bottom of the generator; or we place the chalk
and water and the diluted acid in separate vessels K and L, Figure 1, and
force them through pipes M and N into the generator by pumping air or
gas upon their surface by means of a pump O, worked by hand or in any
convenient way, or sometimes we use a jet of high pressure steam to force the
chalk and water and the dilute acid into the generator by means of a form of
the instrument known as Giffard's patent injector, a description of which is
unnecessary. When the aërated dough has been discharged from the mixing
vessel (by means of the discharging cock herein-after described), we save the
gas which remains in the vessel, either by allowing a part of it to flow into a
similar mixing vessel which has been filled with flour and water, and into
which the remainder of the gas required is admitted from the generator, and
by allowing the remainder to expand through a pipe into a cistern containing
liquor ammonia (in solution) or other suitable substance, by which the gas is
absorbed, and which may afterwards be used to mix for the dough and thus
improve the lightness of the bread.
And where it is desirable, as in apparatus of small size, to save the whole
remainder of the gas, we do so either by pumping it into the generator or
another vessel, or by means of the apparatus shewn in Figure 4. This
apparatus consists of a cylinder A, of sufficient strength, and closed by an
air-tiglit top and bottom. In this cylinder is a floating piston B, of thin
metal, filled with wood, or of other suitable material, which is of such diameter
as to rise and fall easily in the cylinder. The top of this cylinder is connected
by a pipe and cock with the mixing vessel, and the cylinder is of such size
that when the dough has been discharged from the mixing vessel and a com-
munication is opened between the latter and the cylinder, the gas may expand
sufficiently to be reduced to the ordinary pressure of the atmosphere, so that
when the mixing vessel is opened there may be no escape of gas from it.
When the mixing vessel has been refilled with the flour, water, etcetera, and
closed, water is pumped by the pumps C and D from a cistern into the cylinder,
and the whole of the gas is thus forced back into the mixing vessel, and the

page_text: remainder required is admitted direct from the generator. Little gas is
absorbed by the water in the cylinder because of the interposition of the
floating piston, and sometimes we use a flexible diaphragon of india-rubber or
other suitable substance instead of the piston, and sometimes we use a
mercury joint to the floating piston, as shewn at Figure 5, where A is a
groove filled with mercury, into which the lower edge of the floating piston B
descends.
And sometimes we use oil or other suitable fluid in the cylinder instead of
water to prevent any absorption of gas. And where a supply of water exists
under sufficient pressure we prefer to admit such water from a pipe into the
cylinder when required until the gas is partially condensed, and to complete
the condensation by pumping water into the cylinder.
Sometimes we pump
the water back from the cylinder into another close vessel, where it remains
until again required in the cylinder, and thus prevent the loss of any gas
absorbed by the water.
We sometimes use no generator, but make the gas in any convenient way,
and store a sufficient quantity in a gasholder, and we use a mixing vessel
arranged as described, and pump gas into it when required, either by means of
the hydraulic cylinder already described or direct from the gasholder, into which
the surplus gas is allowed to return in the ordinary way. And when we do
this, especially where the apparatus is small enough to be worked by hand,
we use more than one pump, and arrange them so that as the pressure of
the gas increases the power applied shall also increase, as is shewn in plan in
Figure 6, where two cranks are shewn to drive a large and small pump, and
the driving shaft first acts upon the large pump with increasing power by
moving the driving shaft and pinions into gear with the different toothed
wheels shewn. Or sometimes we work the pumps simultaneously and attach
cocks to them, so that as the pressure increases we can disconnect one or
more pumps from the gas reservoir, and open a communication between them.
and the air, so that little power will be required to work pumps so discon-
nected. We thus have a very economical and cheap apparatus of a small
size, as the whole of the mixing and aëration of the dough is effected simul-
taneously in the same vessel, either by means of pumps gradually increasing
in power as the pressure increases or by means of the hydraulic cylinder, or
the high pressure generator shewn and described, whilst the dough may be
readily drawn off from the mixing vessel in pieces of suitable size and weight
by means of the discharging cock herein-after described.
Sometimes we generate the carbonic acid gas by the action of muriatic
acid upon carbonate of soda in such proportions as to form common salt,

page_text: which may be used in making the bread. The discharging cock or valve
above described is shewn at Figure 7.
A is a curved flange attached to the mixing vessel, working against this
flange is a band C of similar curve turning on a centre D, which is also the
centre of the curved flange. In this band is a recess E sufficiently large to
hold one piece of dough of the size into which it is required that it should be
divided. When the band is turned so that the recess E is opposite to the
discharging aperture of the mixing vessel, the recess becomes filled with
dough, and when the band C is turned so that the mouth of the recess is
downwards, the dough falls out, whilst the remaining part of the band closes
the aperture of the mixing vessel. More than one recess may be made in
the band C, so that each may be alternately turned downwards for the dis-
charge of the dough, and presented to the aperture of the mixing vessel to
receive the dough.
Another form of discharging cock which we use is shewn at Figure 8.
A is a conical tube of circular or rectangular horizontal section attached with
its widest part downwards to the discharging aperture of the mixing vessel;
the upper part of this tube is closed by the cock B, and the lower part by a
moveable plate C, either sliding or turning on the hinge D, and the space
between the cock B and the plate C is sufficiently large to hold one piece of
dough of the size into which it is required that it should be divided. This
space may be altered by a lining of wood or other substance. To the cock B
is attached the handle E, which is in connection with the plate C by means of
the lever and pin F, so that the cock and plate shall never be open
together, but that when the cock is shut the plate may be open, and vice
versâ, or they may both be shut together. This discharging cock is used as
follows: When the handle E is in its central position, the cock B and the
plate C are both closed. When the handle is raised the cock is opened whilst
the plate remains closed, so that the intermediate space is filled with dough
from the mixing vessel. When full the handle is turned down, and as soon
as the cock is completely closed the plate is opened wide and the piece of
dough discharged. G is a catch which assists to keep the plate C closed, and
is released by the handle E when the cock B is closed.
In some cases we use two cocks and two plates opening and closing
alternately.
Having now described our said Invention and the manner in which it is
intended to be worked for the purposes for which the said apparatus is to be
employed, we wish it to be understood that we do not claim the making of

page_text: bread with water aërated with carbonic acid or other gas, but we claim as our
Invention,-
First, the novel combination and arrangement of the several parts of the
apparatus herein described for the purposes of manufacturing bread as herein-
before set forth.
Second, the novel combination of the mixing ring and apparatus as described
with apparatus for the manufacture of aërated bread.
Third, the novel arrangement of apparatus for the generation of high
pressure carbonic acid gas for the aëration of bread, as herein-before set
forth.
Fourth, the apparatus arranged in the manner described for the purpose of
pumping gas into a mixing vessel by means of a cylinder into which water,
oil, or other suitable fluid may be forced.
Fifth, the novel arrangements of pumps and the mode of working them
as described in combination with apparatus for the manufacture of aërated
bread.
Sixth, the arrangement of discharging cocks or valves described, by which
dough may be drawn off from any mixing vessel in pieces of the size
required.
In witness whereof, I, the said Edmund Edwards, on behalf of myself
and the said William Augustus Guy and Richard Waugh MacArthur,
hath hereunto set my hand and seal, this Twenty-second day of
December, in the year of our Lord One thousand eight hundred and
sixty-four.
Witness,
T. E. HEWETT,
of 1, York Buildings,
Adelphi.
EDMUND EDWARDS. (L.S.)