A NEW AND IMPROVED METHOD FOR BURNING ANIMAL BONES, FOR THE PURPOSE OF EXTRACTING THE GREASY OR FAT PRO- PERTY THEREPROM, AND LIKEWISE FOR EXTRACTING THE SPIRITUOUS QUALITY THEREFROM AND FOR REDUCING THE REMAINING OR DRY PARTS OF THE BONES INTO A SUBSTANCE SUFFICIENTLY PREPARED FOR BEING GROUND INTO IVORY BLACK; ALL WHICH OBJECTS ARE IN MY SAID PETITION STATED TO BE ATTAINED BY ONE PROCESS ONLY (NAMELY) BURNING BY FIRE
Year: 1813

page_text: TO ALL TO WHOM THESE PRESENTS SHALL COME, I, DAVID
THOMAS, of the Parish of Saint Mary Redcliff, in the City of Bristol, Bright-
smith and Ivory Black Manufacturer, send greeting.
WHEREAS, by Letters Patent under the Great Seal of Great Britain,
bearing date at Westminster, the Thirtieth day of March, in the fifty-third
year of the reign of His most Excellent Majesty King George the Third,
reciting that I, the said David Thomas, had, by my Petition, humbly repre-
sented unto His said Majesty that I had, after much labour, study, and
expence, found out and invented "A NEW AND IMPROVED METHOD FOR BURNING
ANIMAL BONES, FOR THE PURPOSE OF EXTRACTING THE GREASY OR FAT PRO-
PERTY THEREPROM, AND LIKEWISE FOR EXTRACTING THE SPIRITUOUS QUALITY
THEREFROM AND FOR REDUCING THE REMAINING OR DRY PARTS OF THE BONES
INTO A SUBSTANCE SUFFICIENTLY PREPARED FOR BEING GROUND INTO IVORY BLACK;
ALL WHICH OBJECTS ARE IN MY SAID PETITION STATED TO BE ATTAINED BY ONE
PROCESS ONLY (NAMELY) BURNING BY FIRE," and which new method and
Invention I, the said Petitioner, believed would be of general benefit and
advantage; that, by the method theretofore and then used by other persons,
the commodities above described had been obtained from animal bones
(but in less quantities) by three distinct and successive processes (namely),-
first, extracting the greasy or fat property by boiling; secondly, extracting
the spirituous quality by distilling; and, thirdly, producing the substance
fit to be ground into ivory black by burning; that by the three processes
last above mentioned two tons of coals had been and were necessarily con-

page_text: sumed in burning bones sufficient for producing one ton of ivory black,
drawing the fat from such bones, and distilling the spirit therefrom, and
four persons had been and were necessarily employed in the processes,
whereas, according to the new and improved method then used by me, the
said Petitioner, not more than ten hundredweight of coals were consumed in
burning bones sufficient for producing the same quantity of ivory black,
drawing the fat from such bones, and distilling the spirit therefrom; and
that all these purposes could be effected by the attendance of two persons
only for about half the space of time in which four persons would necessarily
be engaged in producing the same quantities and effecting the same purposes
by the said processes then used by other persons; that by the said processes
then used by other persons a considerable waste of the fat and spirit of the
bones took place, and that the processes were extremely offensive to the smell,
whereas by the method then invented by me, the said Petitioner, a very
trifling waste of the fat and spirit took place, and that my process was very
little offensive to the smell; that I, the said Petitioner, was the first Inventor
of the improved method and process above mentioned, and that the same had
never been made or used by any other person or persons, to the best of
my knowledge and belief; and that I, the said Petitioner, most humbly prayed
that His said Majesty would be pleased to grant unto me, my exors, adñiors,
and assigns, Ilis said Majesty's Royal Letters Patent under the Great Seal
ef Great Britain, for the sole use, benefit, and advantage of my said Inven-
tion within England and Wales and the Town of Berwick-upon-Tweed,
and also in all is said Majesty's Colonies and Plantations abroad, for the
term of fourteen years, according to the Statute in that case made and
provided; and that is said Majesty, being willing to give encouragement to
all arts and inventions which might be for the public good, was graciously
pleased to condescend to my said request, His said most Excellent Majesty
did therefore, for Iimself, Ilis heirs and successors, give and grant unto me,
the said David Thomas, Ilis especial licence that I, the said David Thomas,
my exors, admiors, and assigns, by myself and themselves, or by mine or their
deputy or deputies, servants or agents, or such others as I, the said David
Thomas, my exors, adiñiors, or assigns, should at any time agree with, and
no others, from time to time and at all times during the term of years therein
expressed, should and lawfully might make, use, exercise, and vend my said
Invention within that part of the United Kingdom of Great Britain and
Ireland called England, Wales, and the Town of Berwick-upon-Tweed, and
also in all Ilis said Majesty's Colonies and Plantations abroad, in such manner
as to me, the said David Thomas, my exors, adññiors, and assigns, or any of

page_text: them, should in mine or their discretion seem, meet; and that I, the said
David Thomas,. my exors, admiors, and assigns, should and, lawfully might
have and enjoy the. whole profit, benefit, commodity, and advantage from
time. to. time, coming, growing, accruing, and arising by reason of the said
Invention, for and during the term of years therein mentioned, to hold,
receive, and enjoy, the said licence, powers, priviledges, and advantages therein-
before granted, unto me, the said David Thomas, my exors, adiñiors, and
assigns, for and during, and, unto the full end and term of fourteen years from
the date thereof next ensuing, according to the Statute in such case made and
provided; in which said Letters Patent, among other things, is contained a
proviso obliging me, the said David Thomas, by an instrument in writing
under my hand and seal, particularly to describe and ascertain the nature of
my said Invention, and in what manner the same is to be performed, and
cause the same to be enrolled in His Majesty's High Court of Chancery within
two calendar months next and immediately after the date of the said recited
Letters Patent, as in and by the same, reference being thereunto had, will
more fully and at large appear.
NOW KNOW YE, that in compliance with the said proviso, I, the said
David Thomas, do hereby declare that the nature of my said Invention, and
the manner in which the same is to be performed, is described, and ascertained
in the Schedule to these Presents, comprizing a certain Plan or certain Plans
hereunto, annexed, and the several explanations thereof, which are also here-
unto annexed, and refer to the said Plan or Plans, or different parts thereof,
and which Plan or Plans and explanations are severally signed by me, the said
David Thomas.
In witness whereof, I, the said David Thomas, have hereunto set my
hand and seal, this Twenty-first day of May, in the year of our Lord
EXPLANATION OF THE SEVERAL FLANS OR DRAWINGS DRAWN UPON
THE SKIN OF PARCHMENT DEREUNTO ANNEXED.
Figure A represents the ground plan of six ovens with their pots, receivers,
and water vessels herein-after described, having the tops or upper parts of the
two exterior ovens removed so as to expose the pots and internal parts, and
flues of such exterior ovens to view, and such two ovens are represented
by the Figures 1, 1, and are two feet eight inches in width, and six feet in
length or depth backwards. 2, 2, represents the grate bars of the furnaces

page_text: belonging to such two ovens, such furnaces being about one foot square in
front or width and height, and six feet in length or depth backwards, being
sunk a little below the bed of their respective ovens, as represented by d in the
several furnaces of Figure C. 3, 3, 3, 3, represent the plan of four brick pillars
or fire breakers, as also represented by o in Figure F, and by fin Figure C,
which are for the purpose of separating the ascending flames described in
Figure C, so as to secure the regular action, and break the force of the fire,
which would otherwise unavoidably operate too strongly against that side of the
pot nearest to the furnace; and 4 represents a saddle of sheet iron placed
between such breakers and the pots, and also represented by g in Figure C,
and which is so placed for the further protection of that side of the respective
pots from the too intense heat, as before described. 6, 6, 6, 6, represent the
four flues from each oven to the chimney stack, each of which flues are four
inches and a half high by six inches wide, and the partition between such
flues is eight inches wide, and the farthest of such flues extends backwards
only four feet from the front of the oven, and the reason for which is to
prevent the fire from passing off at the farthest end, for a draught or flue at
such back or farthest end of the oven would cause the heat to be much
stronger at that end than at the front end.
projecting in front from the bed of the oven.
receiver (immersed in the vessel of cold water 11) for the purpose of receiving
the gas issuing from the top of the pots through the pipes marked 9, as
herein-after more particularly represented by Figure C. 10, 10, are two
auxiliary condensing receivers placed at each end of and communicating with
condenser 8, and they are immersed in the vessels of cold water 12, 12, in
which three vessels of cold water there is a continual ingression and digression
of water, as herein-after more particularly mentioned. 15, 15, represent two
vessels or receivers for the purpose of receiving the fat issuing from the bottom
of the pots through the pipes marked 16, as herein-after more particularly
described by N in Figure C, and also by T in Figure E.
17 represents an iron plate
8 represents a condensing
Figure B represents the ground plan of the chimney stack D, having three
ovens on each side, with their respective flues falling into it at the Figures 7,
such Figures 7 representing the flues of the chimney stack, and each of the
flues of such chimney stack being four feet in length or depth backwards and
seven inches wide.
Figure C is a front or perspective view of the aforesaid six ovens situate on
each side of D, the chimney stack, and the reddish colour arising from the
furnaces marked d represents the action and course of the various fires round
the several. pots herein-after particularly described. The fire for each oven is

page_text: confined to the separate space or passage belonging to such oven round its
pot, and through the several channels or flues, as also described by 6, 6, 6, 6,
in Figure A, and those fires which are farther removed from the chimney
stack assist those fires which are nearer the chimney stack by the heat of such
farther fires being conveyed through such channels or flues curvedly over
such nearer fires, as represented by the brick arches marked c, by which
means there is a saving of fuel to the extent of about three parts out of four,
inasmuch as by these means the furnaces or fires of the ovens 3 and 4 which
are nearest the chimney stack require less fuel than those of the ovens
2 and 5 which are farther removed therefrom, and in like manner the furnaces
or fires of the ovens 2 and 5 require less fuel than those of the ovens 1 and 6
which are farthest removed from the chimney stack. The gas or smoke from
the six ovens before mentioned ascends the chimney stack D in six flues, as
before described in Figure B, up to n, n, n, and from thence passes into three
flues, and issues out at the top. 1, 2, 3, 4, 5, 6, represent the front or
entrance ends of six ovens built of fire-bricks, in which the pots herein--
after described are put. These ovens are made just large enough all round
to admit such pots to be moved in and out and to admit the flames issuing from
the furnaces to encircle the pots in order to communicate a regular heat to
every part of them, which heat is communicated to the under part of such
pots by means of the rollers herein-after mentioned, which raise the pots from
the bed of the oven, so as to admit the heat under them.
represent the curves or arches of the ovens and flues, which pass curvedly
over each other without any communication one with another; and that the fire
may pass over the nearer ovens from the further ovens, as before stated,
there are necessarily one of such arches over each of the pots G and M, two of
them over the pots IT and L, and three of them over the pots I and K; and
all of such arches are brought to a flat surface or level floor at the top, which
is covered with flat brick tile, on which is dried the sal ammoniac solely by
the ascending heat from the ovens below, but for which purpose other persons
are obliged to have a separate fire. G, H, I, K, L, M, represent the front or
entrance ends of six iron pots placed in their respective ovens, each about two
feet and three inches wide at the bottom, eighteen inches high from the base
to the top edge or middle of the curve thereof, and five feet long or deep from
the front to the back part thereof; but they may be made round or any other
form which may be thought most convenient, and may be made of cast or
wrought iron, the door of each of which pots forms the whole of such front end
thereof, and rests upon half of an inch shoulder of iron, and is inclosed all-
round by a projecting ledge or rim of iron, through which there are small.
e, c, e, e, c, P,

page_text: holes made for iron pegs, by which the ends or doors are fastened on and
made air-tight with loam. These pots are of the same dimensions at the back
or further end, and throughout the whole space from front to back, or at the
front or entrance ends before described; they will contain from three to four
hundredweight of raw bones cach, and when filled they are. brought to and
taken from the ovens by means of hand truckells, and conveyed to and from
the internal parts of the oven upon and by means of two iron rollers lying on
the bed of each oven, as.represented by the dotted. lines under 5 in Figure A
The front roller.is.about two inches diameter, and the back roller about four
inches diameter,. for the purpose of keeping the front part of the pot rather
lower than the back part, so as the more readily to convey the fat from the
bones, as herein-after mentioned. h, h, h, h, h, h, represent six pipes to
convey the fat produced by the burning of the bones from the bottom edge of
the front or entrance end of the pots, and which front or entrance end of the
pots being rather lower than the back or further end of such pets by reason of
the variation in the size of the rollers, as before stated. This position of the
pots facilitates the running of the fat towards the front end, and out the pipes
marked into the receivers N, N, which pipes h and their receivers are
further described by 15 and 16 in Figure A, and also by 'n and T in Figure E;
and such pipes marked h, further to facilitate the running of the fat into the
receivers N, N, must decline at least forty degrees from an horizontal position.
i, i, i, i, i, i, represent six pipes projecting. from the top of the door at the
front or entrance end of the pots to convey the gas arising from the burning
bones into the condensing receiver 0 (made air-tight) which is immersed.in
tlie vessel P, as herein-before described by 8 in 11, Figure .A, which vessel P
is filled with cold water, in order the more readily to condense the gas
issuing from the pots; and, as the cold water in such vessel P is liable to
be heated by the constant flowing of the hot, gas through the pipes i into. the
condensing receiver O, there is therefore a cock, as represented by 14
in Figure A, for the purpose of letting out, the hot or warm water, and
a pipe, as represented by S in Figure E, in order to supply and refill such
vessel P with cold water.. Q, Q, represent two other condensing receivers
which are also made air-tight, and immersed in the vessels of cold water
R, R, as described by 10 in 12, Figure A; with these receivers Q, Q, the
other receiver O communicates by means of the pipes k, k, which convey
such part of the gas as shall escape uncondensed from the condensing
receiver into the condensing receivers. Q, Q, wherein the same becomes
fully condensed. There is in each of these vessels R, R, a cock, as. described
by 14, in Figure A, and a pipe as at S in. Figure E, to be used for the same

page_text: purpose as those in the vessel P, before described. The condensing receivers
O and Q, Q; have taps and cannels made of wood, as represented by 13, 13,
13, 13, in Figure A, which penetrate the respective sides of the water' vessels
P and R, R, into the condensing receivers O and Q, Q; and by which the
condensed gas or spirit is drawn from such receivers.
Figure E is a transverse section of parts of the chimney stack and receivers,
cutting Figures A, B, and C, D, at the blue lines a, a, and b, b, shewing the
ends of the flues marked r, proceeding from their respecting ovens on the
right-hand side of the chimney stack. The receivers may stand either on
the same floor with the furnaces before described; or on an under floor,
as represented by this Figure E, where they are placed in an arched cellar,
upon which the ovens and chimney stack are built. W' represents stonework
supporting the arch y, which is unequally loaded by the ovens and chimney
stack standing on one side of its centre, and if the receivers stand on an under
floor there must be an elbow in some part of the pipe 7, as described by m,
from which it may descend in a straight direction to such condensing receivers
on the under floor; the pipe is therefore drawn with an elbow at about
eighteen inches distant from the place where it is fixed in the door of the pot
in a direction of about forty degrees from an horizontal position, and just
appears through the oven door; and from this elbow the pipe falls in a
straight direction into the condensing receiver O. The pipes and i are
necessarily divided into three parts for the purpose of putting such pots in
and taking them out of their ovens, the top part of such pipes being fixed to
the end or door of the pot, the bottom part fixed to the condensing receiver,
and the middle part of such pipes being removed when the pots are taken out
of their ovens, and put on and made air-tight with loam when they are
placed therein; all the pipes before mentioned project from the pots through
the oven doors, for which holes are left in all such oven doors.
Figure F is a transverse section cutting C at e, e, shewing the side of the
breakers o, which breakers are for the purpose of separating the ascending
flame, as herein-before stated, and the several letters p represent the ends of
the flues which proceed from the two ovens described by 1 and 2 in Figure C.
The chimney stack D is about nine feet eight inches wide, and the six ovens
and chimney stack together occupy a space of about thirty-six feet in width in
front by seven feet six inches in length or depth backwards.

page_text: AND BE IT REMEMBERED, that on the Twenty-first day of May, in
the year of our Lord 1813, the aforesaid David Thomas came before
our said Lord the King in His Chancery, and acknowleged the Specifi-
cation aforesaid, and all and every thing therein contained and specified,
in form above written. And also the Specification aforesaid was stampt
according to the tenor of the Statute made for that purpose.
Inrolled the Twenty-second day of May, in the year of our Lord One
thousand eight hundred and thirteen.