CERTAIN IMPROVEMENTS IN TANNING HIDES AND OTHER SKINS
Year: 1824

page_text: TO ALL TO WHOM THESE PRESENTS SHALL COME, I, HOWARD
FLETCHER, of Walsall, in the County of Stafford, Saddlers' Ironmonger, send
greeting.
WHEREAS His most Excellent Majesty King George the Fourth did, by
His Letters Patent under the Great Seal of His United Kingdom, bearing
date at Westminster, the Nineteenth day of January 1824, in the fourth
year of His reign, give and grant unto me, the said Howard Fletcher, my
exors, adññors, and assigns, His especial licence, full power, sole privilege
and authority, that I, the said Howard Fletcher, my exors, adññors, and assigns,
during the term of years therein mentioned, should and lawfully might make,
use, exercise, and vend, within England, Wales, and the Town of Berwick-
upon-Tweed, my Invention of "CERTAIN IMPROVEMENTS IN TANNING HIDES AND
OTHER SKINS;" in which said Letters Patent there is contained a proviso
that if I, the said Howard Fletcher, shall not particularly describe and
ascertain the nature of my said Invention, and in what manner the same is
to be performed, by an instrument in writing under my hand and seal, and
cause the same to be inrolled in His Majesty's High Court of Chancery within
four calendar months next and immediately after the date of the said Letters
Patent, that then the said Letters Patent, and all liberties and advantages
whatsoever thereby granted, shall utterly cease, determine, and become void,

page_text: as in and by the same, relation being thereunto had, will more fully and at
large appear.
NOW KNOW YE, that in compliance with the said proviso, I, the said
Howard Fletcher, do hereby describe and ascertain the nature of my said
Invention, and a manner in which the same may be performed, by a descrip-
tion thereof, referring to Drawings and Figures annexed.
The object of my Invention is to tan hides and skins in a shorter space
of time than by the process now commonly practised. The leather is rendered
equally tough and suple, and at the same time finer than that tanned in the
usual way. I do not claim the use of any particular sort of bark or liquor,
all the kinds now commonly used are suitable for my mode of tanning. The
hides or skins are also cleansed and prepared by the common method, which
is too well known to render a description of it here necessary. My Invention
consists solely in tanning hides or skins in air or water tight vessels or pits,
by the application of internal pressure; but before I proceed further to de-
scribe my Invention, I do now declare that I do not take out my Patent for
or claim to myself the use of such apparatus only as I shall hereafter mention,
but under His Majesty's Letters Patent I do claim solely the privilege of
tanning hides or skins in air or water tight vessels or pits, by the application
of internal pressure, produced or applied in any way whatever. I make use
of the same quantity of bark or astringent substance, whatever it may be, as is
commonly used. The liquor is made in the same way, and the hides or skins
are cleansed or prepared by the common means; in short my system differs
from the common way of tanning only in making use of air or water tight
vessels or pits, and in applying internal pressure. The apparatus which I
herein describe is that which I employed for my experiments, without regard.
to economy. For a large scale pits or vessels made of wood lined with lead
or any other material, so as to render them air or water tight, and firmly
bound together with iron, would answer the purpose. In order to produce
the pressure, I have employed, in first place, air, forced into the vessels or pits
by a condensing air syringe; 2nd, I made use of a column of water on the
principle of the hydrostatic bellows; the force generally employed has been
about 9 lbs. or 10 lbs. on each square inch of the internal surface; but I do
not confine myself to any particular degree of pressure, the greater the force
employed the quicker the process will be effected.
Without further preface, I shall proceed to illustrate my Invention by
Drawings, &c. Fig. 1 represents the pit or vessel made of cast iron, sufficiently
strong to maintain the force required, lined with lead, and measuring 5 feet by
4 feet, & six feet deep, let into the ground as far as the dotted line. The pro-

page_text: purpose
H is a
jecting pegs A are made also of iron, about 4 inches in length, for the
of attaching eyed bolts as A, A. Bis a waste pipe secured by a stopcock; C.is
strong wooden post, with a hook D; E, E, are two short posts, with nicks cut at
right angles as A, sufficiently wide to receive the iron peg F; the short screwed
pipe G is for introducing the pressure. Figure 2 is the lid of the vessel before
described, having flaunches with holes on the outer edge, as represented in
Drawing, the inner side covered with lead similar to the pit.
ring firmly attached. The strong projecting pieces I, I, when placed into
the nicks of the short posts E, E, and secured by the iron pin F, are intended
to act as hinges. Figure 3 is the eyed bolt before mentioned, to be hooked
on the projecting pegs A at one end, and passed through the holes in the
lid represented by Fig. 2 at the other end; the vessel by the assistance of
screw nuts, is then rendered air and water tight. Fig. 4 is a metal tube
or column to be placed in a perpendicular direction against building, or in
any other convenient situation, its length regulated according to the pressure re-
quired. The tube is connected with the pit by the screwed pipe G. The cask
L is merely for a reservoir to keep up a constant supply of liquor in the tube.
Having so far explained my apparatus, I shall now endeavour to describe
the process. We will suppose the pit Fig. 1 to be filled with tan liquor. A
sufficient quantity of hides or skins, having been previously cleansed and
prepared, are then immersed in the pit. The lid, Figure 2, is then shut down,
and screwed up water-tight, by the eyed bolts represented, Fig. 3. The stop
cock K is now opened, and the column Fig. 4 filled with tan liquor, by which
a pressure is produced in the pit, which will have the effect of forming the
liquor into the pores of the hides. The tanning process is now to be carried
on exactly as in the usual mode, the hides or skins requiring to be moved
from the pits, and drained daily, and replaced in the pit in the manner before
described. As I use the same quantity of bark as in the common method
of tanning in a shorter space of time, it must be obvious that the liquor must
be applied stronger, but this I consider requisite only in the latter stages
of the process.
I do not pretend to specify any exact time the tanning
process will occupy by the method herein described, as it will entirely depend
on the strength of the hides or skins, and on the attention they receive.
In witness whereof, I, the said Howard Fletcher, have hereunto set my
hand and seal, this Fourteenth day of May, in the year of our Lord
One thousand eight hundred and twenty-four.
HOWARD (L.s.) FLETCHER.

page_text: VARIAN
AND BE IT REMEMBERED, that on the Fourteenth day of May, in
the year of our Lord 1824, the aforesaid Howard Fletcher 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 stamped according
to the tenor of the Statute made for that purpose.
Inrolled the Eighteenth day of May, in the year of our Lord One
thousand eight hundred and twenty-four.