A TAN PIT UPON A NEW CONSTRUCTION, AND A MODE OF TANNING BY WHICH LEATHER WILL BE TANNED IN ABOUT A SIXTH PART OF THE USUAL TIME, AND MUCH LESS LABOUR AND EXPENCE, AND WHEREBY LEATHER IS RENDERED IN EVERY RESPECT MUCH SUPE- RIOR TO THAT TANNED BY ANY MODE HITHERTO INVENTED
Year: 1797

page_text: TO ALL TO WHOM THESE PRESENTS SHALL COME, I, ROBERT
Cross,
CROSS, of Quaker Brook, within Hoghton, in the County Palatine of Lan-
caster, Tanner, send greeting.
WHEREAS His present Majesty King George the Third, by His Letters
Patent under the Great Seal of Great Britain, bearing date at Westminster,
the Twenty-sixth day of April, now last past, hath given and granted unto
me, the said Robert Cross, my executors, administrators, and assigns,
special licence, full power, sole privilege and authority, to make, use exer-
cise, and vend, within England and Wales, and the Town of Berwick-upon-
Tweed, during the term of years therein mentioned,my Invention of a "A TAN
PIT UPON A NEW CONSTRUCTION, AND A MODE OF TANNING BY WHICH LEATHER WILL
BE TANNED IN ABOUT A SIXTH PART OF THE USUAL TIME, AND MUCH LESS LABOUR
AND EXPENCE, AND WHEREBY LEATHER IS RENDERED IN EVERY RESPECT MUCH SUPE-
RIOR TO THAT TANNED BY ANY MODE HITHERTO INVENTED;" which Letters
Patent contained a proviso, requiring me, the said Robert Cross, by an
instrument in writing, 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 after the date of the said 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 I, the said Robert Cross, in compliance with
the said proviso, do hereby declare that my said Invention of a tan pit, and
mode of tanning, is described in manner following, that is to say:
The tan pit may be constructed of wood, stone, or any other substance fit
for the purpose, but wood is most eligible, and of any size or shape most
convenient; the bottom thereof may be made of stone, metal of any kind, or
other substance, but lead will be found the best and cheapest, which must be
turned up the breadth of four inches on each side and end, and closely nailed,
or otherwise fastened to the inside of the pit, a lining of strong woollen cloth
being put betwixt the leaden and wooden parts to prevent the loss of any
wooze; if the bottom were fastened to the outside, in case of decay or accident
arising to it, it could not be taken out without removing the whole pit, which
will not be necessary if fastened to the inside. This pit must be placed on
brick or stone walls, eighteen inches asunder and twenty-four inches high,
of the shape of the pit itself, and care must be taken to let the leaden bottom
rest upon the wall on each side and end for fear of the fire communicating to
the wood. A bed of well-tempered puddle or clay must be laid upon the
walls under the pit to keep it water-tight, and three or four iron bearers must
be laid across under the bottom, to prevent its bursting by the weight of wooze.
The fire (which will not be required oftener than every other day in order to
keep the wooze.of.a gentle degree of heat). must be placed; on barrs.under
the pit, ten inches below the bottoni, and continued, the whole; length thereof
The flue or chimney for the smoke to ascends through must extend about, one
foot beyond the end of the pit,, and be so turned up.'as sufficiently to clear the
surface of the ground. The: pit: must be well; closed in on the outside with
clay or puddle, except,at the front thereof, which must be secured by.a.,bricks
or stone wall; or, strong flags or planks well supported, raised, as high as the
pit itself, leaving a space. of nine.inches, betwixt such wall flags or planks,
and the pit also to be filled up with puddle oraclay. The entrance, for the fire
must be arched over with, brick, or covered with a strong flag.even-with, the
wall, which is twenty-four inches high, .to, support the puddle and end, of the
pit. And, as the. leather would receive great dainage from being, placed
in contact with. the leaden bottom of the pit, close jointed boards; about one
inch thick, must be. placed.upon a wooden bearer at each end, about six, inches.
from the bottom of the inside of the pit, and to fit close.to the sides and ends,
except the four.corners.thereof whichemist. be cut offato, leave a space of five
inches in each angle of, tlie. pit, which spaces must be continued to the top of
the pit by placing a narrow board across the angle, but not so as quite to close
'

page_text: it up, but to admit the warm woozes-from below to operate upon the leather
equally, and to prevent the bark within the pit from clogging up the crevices
and thereby prevent the free circulation of the wooze; a piece of canvasszor
rough cloth may be nailed over each 'angle to guard it.The approach to the
fire-place-may be by means of steps or in any other manner most convenient...
By a tan pit thus constructed; two otliers, one on eacli side of it, may-be
used in the following manner without any more fire-places-Place another pit
of the same size, made wholly of wood or other substance, upon the earth on
each side of the tan pit, and at the distance of-five inches from it! and upon a
level with it; let there be, a communication betwixt the side pits and the
middle pit by means of two or more metal pipes, each having a bore of
four, inches, diameter,, being fixed in, the middle pit about two (inchest from
the bottom, and so extending into each side pit at the like distance from, their
bottoms, in order to convey the warm woozes from the middle, pit to the side
pits; and when it becomes necessary to prevent, the communication; betwixt
the pits, it may be effected by means of a valve fixed at the end of each pipe
within the middle pit, which may be easily opened or closed at pleasure, by a
strong wire being fastened to each. valve and extending a little above the side
of the pit. The spaces betwixt the three pits must be well closed in with
clay or puddle.
The leather, whilst tanning by the above, process, should be. frequently
handled to prevent the wooze from contracting the grain of it unequally; and
it will be found to be completed in one-sixth part of the time which the old
common mode requires, with less labour and expence, and will be much
superior in point of durability.
The construction of my new-invented tan pit will also be clearly perceived
by the model which accompanies this my Specification, referred to herein-after,
that is to say:-
REFERENCES TO THE MODEL OF MY NEW INVENTED TAN PIT.
A the wooden part of the tan pit; B the metal or stone bottom, turned up
and fastened to the wood part; C, the brick or stone walls whereon the bottom
of the pit must rest; D, the iron bearers to support the bottom of the pit;
E, the iron bearers and bars on which the fire must be placed; F, F, the flue
or chimney for the smoke to ascend through; G, the brick or stone wall in
front of, and nine inches from the pit; the space to be filled up with clay or
puddle; I the arched entrance for the fire; I, the close-jointed boards, laid
within the pit upon bearers of wood six inches from the leaden bottom; I, I, I, I,

page_text: the four partitioned angles within the pit, through which the warm wooze is
to ascend, and which must be covered over with canvass; J, J, the metal
pipes for conveying the wooze from one pit to the other; K, K, the valves and
wire by which the pipes are to be closed or opened; L, one of the side pits,
which may be constructed in the same manner as the above-mentioned pit, but
wholly of wood and placed upon earth or clay.
In witness whereof, I, the said: Robert Cross, have hereunto set my
hand and seal, this Twenty-second day of May, One thousand seven
hundred and ninety-seven
Inrolled the Twenty-fifth day of May, in the year above written.