NEW! IMPROVEMENTS IN THE ART OF TANNING AND DRESSING HIDES AND SKINS
Year: 1802

page_text: TO ALL TO WHOM THESE PRESENTS SHALL COME, I, THOMAS
MARTIN, of Goswell Street, Clerkenwell, in the County of Middlesex, Sadler,
Collar, Harness Maker, and Tawer, send greeting.
WHEREAS His most Excellent Majesty King George the Third did, by
His Letters Patent under the Great Seal of the United Kingdom of Great
Britain and Ireland, bearing date at Westminster, the Nineteenth day of
April, in the forty-second year of His reign, give and grant unto me, the
said Thomas Martin, my executors, administrators, and assigns, His special
licence, full power, sole privilege and authority, that I, the said Thomas
Martin, my executors, administrators, and assigns, during the term of years:
therein expressed, should and lawfully might make, use, exercise, and vend,
within England, Wales, and the Town of Berwick-upon-Tweed, my "NEW!
IMPROVEMENTS IN THE ART OF TANNING AND DRESSING HIDES AND SKINS;" in which
Letters there is contained a proviso, obliging me, the said Thomas Martin;:
under my hand and seal, to cause a particular description of the nature of;
my said Invention, and in what manner the same is to be performed, to be
inrolled in His Majesty's High Court of Chancery within one calendar month
next and immediately after the date of the said in part recited Letters Patent,
as in and by the same, relation being thereunto had, may more fully and at:
large appear.

page_text: NOW KNOW YE, that in compliance with the said proviso, I, the said
Thomas Martin, do hereby declare my Invention to be described in manner
following, that is to say:-
My Invention consists in placing a boiler of convenient size as near a
reservoir of water as the nature of circumstances will admit, with a pipe near
the edge of the boiler to convey the warm water into a tub or vat, which
should be placed near to and rather higher than the vats in which it is intended
to place the raw goods, and those working out of the limes, so that the first
may empty itself into a second or third vat, or into as many as may be deemed
necessary; these vats must have false bottoms for the reception of the sand
and filth, but a pipe with a cock between the vats is preferable to the method
of flowing; the first tub or xat is. not intended for goods, but only to regulate
the warmth of the water. The blood and filth congealed in the pores of the
pelt when the animal was dying, together with the dirt collected in the slaughter
house, markets, &c., &c., will, by the application of the water rather warmer
than blood heat, be more readily separated from the skins and will sink under
the false bottoms, whence it may be conveyed into a sewer by pulling out a
plug from the real bottoms. The application of warm water will revive dried
hides, and will greatly expedite the process of tanning or dressing by expanding
the pores for the reception of the ooze, allum liquor, &c. The hair, and
particularly wool, in this manner will be more easily cleansed of the dirt. The
raw hides may, however, be immersed in cold water to cleanse them from the
external blood and filth, previous to their being put into the warm water. By
this method the hides or skins will not require so much drenching (if any) in
soars as in the mode commonly used. The hides being perfectly cleansed from
blood-and extraneous matter, in the usual manner, with a knife on a bearn, are
ready for the limes; when they are sufficiently limed and the hair taken off,
they should be worked out clean from the lime with warm water; any
remaining blood or lime in the pores prevents the ooze or other materials for
tanning, tawing, currying, or dressing of leather from penetrating into the
fibres, and renders the leather hard when tanned or otherwise dressed.
:
Having described my method of preparing-the-goods-for-the-ooze.and.sub-
sequent processes, I shall now proceed to the vats. I construct a circulation
plant, of sixteen pits or vats; each of about six feet long, four feet and a half
wide, and six feet deep, but the principle will equally. apply to any number of
any dimensions; the pits must be constructed of sound wood, the upper plants
ef oak; the ground on which the vats are to rest should be level and clear of
all stones to prevent any irregular bearing, and then place pieces of wood,
resembling flooring joists, at equal distances, at least one under each side and

page_text: partition, one under the middle of each pit, and one under each end. On the
joists I fix a well-jointed sound bottom, with grooves into which I fit the sides,.
extremities, and partitions; the sides and extremities two inches higher than
the partitions. The sides, ends, and three side partitions should be of planks
that extend throughout or be carefully jointed; twelve end partitions. will
divide the whole into sixteen pits.
The vats may be on the surface or the edge, eighteen inches above the level
of the yard. As the sides and ends are liable to bulge from the weight of oozo,
fix several metal cramps at the bottoms, ends, and sides; also cut a groove at
the ends of the end partitions and fix a metal bar of sufficient size across the
ends of each; make loose false bottoms with crevices or holes and not less than
six inches from the real bottoms, that the filth that accumulates in the vacancy
may be removed. At least two inches above the false bottoms must be circu-
lation holes at transverse corners, large enough to permit the liquor to run one
vat from another. Fix ledges, mitered and hollow two-thirds of their length, on
the side the ooze runs from, and others on the opposite side, hollowed one-third
of their length, and that at the lower ends; guard boards should be put on the
side the ooze runs from, with holes or crevices from the top to the false bottoms,
and likewise on the opposite side, with as many holes as the former, but con-
tained in the lower half of the guard boards; these boards being placed at
transverse corners will prevent the hides from lying flat against the circulation
holes, or bark, &c. from clogging them up. Fix slips or rabbits of wood at
cach side of the circulation holes, with valves or sliding doors to move up or
down by means of a strong wire, or bungs or plugs to put in or take out.
For the conveniency of going from one vat to another, it will be necessary
to lay planks on the ends of the vats; these planks should be eighteen inches
broad, three inches thick at one end and reduced gradually to two inches at
the other end, and rather hollow in the middle, if singly covered; at the thinnest
end over the joint, between the side of the vats and the ends of the planks,
must be nailed a piece of leather or other substance, to prevent the rain water
from falling into the vats from the covers. On the under side of the planks
fix ledges to fit the partition; and brackets nailed on the sides of the vats, at
the ends of the planks, will be a steady support for them without being fixed.
It will be essentially requisite to remove, and frequently, by this process, to
handle, the goods in one or other of the vats without being interrupted by the
circulation of the ooze; at the same time, the circulation of the ooze need not
be impeded. In the annexed representation, suppose L is to be emptied and.
the ooze to continue its circulation from K to M, the valves or sliding doors in-
K and M on the side next to L must be pushed down or pulled up; provido

page_text: {
a loose pipe of'sufficient bore, eight feet long with returned ends, lay this pipe
with the ends upwards, stop one end with a bung or plug, fill the pipe at the
other, end with ooze;-stopping that also, then turn the pipe with the returned
ends downwards, both being below the surface of the ooze, one end in K (the
pipe. lying across L) and the other in M, pull out the bungs by means of
thongs for that purpose, the pipe will convey the ooze from K to M; in the
meantime the goods in L may be handled, removed, and the vats emptied or
.cleaned.
By means of a pump or jet you may remove the ooze out of P into A with
B and C, or as many as are deemed necessary to contain bark; the ooze will
be refreshed each time of circulation from the acid retained in passing through
the goods, and will run clear above the false bottoms, leaving the filth undis-
.turbed under them.
.
"
Another method I adopt is, to elevate a large vat three feet above the
surface of the ooze. Let the ooze be pumped from and into the elevated
vat, which may be made a receptacle for placing the goods, bark, &c., and
will answer the purpose nearly as well as any of the vats. Suppose the fire
for heating the boiler before mentioned to be twelve yards from the elevated
vat, a second boiler, with a cock near the bottom, may be placed at the same
fire, with a lid to prevent the soot from falling into it, which would stain the
leather. The elevated vat must have a pipe with a cock in it extended through
the bottom, with ozier or wire work, or guard board with holes, to prevent
bark or filth from going down (which will convey the cold ooze into the second
boiler, and will likewise cause the warm ooze (the boiler becoming filled) to run
down a pipe of larger bore, placed near the edge of said boiler, leading into
vat A. This method may be adopted for warming alum liquor or other
materials for dressing leather.
It is preferable to have the whole of the vats under cover of a roof or a shed.
They may likewise be covered singly, by placing boards eighteen inches broad
edgeways, at the ends of the pits on the planks, with brackets to support them-
and notches at the ends to fit to each other; at the end of these must be placed
boards, eighteen.inches broad, edgeways, also gradually terminating in a point
at the other end of the pit, provided with metal hooks to fit into eyes in the
boards, with brackets, and likewise, stumps to fit into lioles at the edges of
the pits, to keep them steady. Near the upper edges of the side boards must
be cut grooves, into which must be fitted boards across the pits, with edges to
lay over each other, so as to carry off the rain water into the hollow planks.
By placing mats of straw or flags on these covers the frost will be effectually
prevented from injuring the goods.

page_text: There being several plants of pits in a yard of this construction, the oozes
may be made of different degrees of strength of the tanning principle, at the
tanner's pleasure, one of which plants of vats may be used for the bark, &c.,
after the greatest part of its virtue has been exhausted. By placing chalk
under the false bottoms it will assist in taking away the acid retained when in
conjunction with the goods. There being no hides or skins in this plant, the
ooze may be made warmer, which. will draw the remaining virtue from the
bark, &c., and make a good soft ooze, fit to be placed with goods, and make
a considerable saving of that article..
The necessary pumps may be wrought by men, or by the bark mill commonly.
turned by horses, or by a third boiler at the same fire, the steam of which may
be employed by means of an engine to grind the bark and work the pumps.
The fire for the before-mentioned purposes will prove of utility in drying the
new bark and making it grind well, and likewise in drying the old exhausted
bark for burning; also for drying the leather, hair, wool, glue, pieces, &c., &c.
By turning the cock in the pipe leading from the elevated vat, the warmth
of the: ooze may be regulated to little warmer than the heat of the animal when
alive, by which the tanners and dressers of leather are enabled to work in the
most severe and intense frost; the pores having been opened for the extraction
of the blood, &c., and those whence the hair grew, by this circulation leaving the
filth, under the false bottoms. The clear warm ooze, &c., having penetrated
the fibres, they will admit materials for currying and bringing, the leather to
that state of perfection requisite for manufacturing for different purposes in a
few days, and be of longer durability, more tough and elastic, of greater
strength, and far less expensive, than by the former methods.
Let a vat or well (being made sound) be sunk at some distance from the
vats, with a pipe in it from near the bottom P; this well being deep and large
enough to contain the ooze of any one of the vats below the bottom of such
vats; any vat requiring to be emptied, it may be effected by placing the end of
a pipe to the bottom of the vat; the necessary circulation holes being shut, the
other end of the pipe being in the well, but lower than the bottom of the vat,
the ooze will pass into the well. The same well, pump, and boiler will serve for
several plants of vats, by opening or shutting the valves against the circulation
holes in the vats leading to the well. This done, the whole of the ooze may
be pumped into the elevated vat, whence it will run down into the boiler.
A pipe with a screw may be fixed, or a trough placed to the cock near the
bottom of the boiler, to convey the ooze into the vat; thus, you may remove
the ooze from one set of vats to another with very little trouble, by only altering,
the valve against the pipes leading to the well, and turning the cocks in the

page_text: pipes leading from the boiler to the different plants of pits. Old vats in the
common method, at a distance from each other, will require pipes from one to
another, to make circulation holes.
From some experiments I have made for months past, I find as good leather
may be made by my method of tanning from shavings, sawdust, or chips
containing a tanning principle (particularly oak), as from bark.
N.B. The hides of horses and other animals that die of themselves, the
congealed blood, filth, and dirt is seldom totally extracted, which prevents the
ooze, and other materials for dressing and. currying, from penetrating into the
fibres. These hides, when tanned or dressed, are easily known, and are deno-
minated casualty ones. By the adoption of my method of preparing the skins,
the blood, &c. may be easily and more compleatly extracted, and those bides;
when manufactured, will be nearly equal to slaughtered hides or skins.
In witness whereof, I; the said Thomas Martin, have hereunto set my
hand and scal, this Nineteenth day of May, in the year of our Lord
One thousand eight hundred and two.
T. H. D. HERON.
AND BE IT REMEMBERED, that on the Nineteenth day of May, in
the year of our Lord 1802, the aforesaid Thomas Martin came before our
said Lord the King in His Chancery, and acknowledged the Specification
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 Statutes made for that purpose.