AN EXPEDITIOUS MODE OF UNHAIRING, MASTERING, AND TANNING VARIOUS DESCRIPTIONS OF HIDES AND SKINS
Year: 1841

page_text: FURNIVAL'S SPECIFICATION.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JAMES
FURNIVAL, of Warrington, in the County of Lancaster, Tanner, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent under the Great Seal of Great Britain, bearing date at Westminster,
the Twenty-ninth day of March, in the fourth year of Her reign, did give
and grant unto me, the said James Furnival, my exors, admors, and assigns,
Her special licence, full power, sole privilege and authority, that I, the said
James Furnival, my exors, admors, and assigns, and such others as I, the said
James Furnival, my exors, admors, and assigns, should at any time agree with,
and no others, from time to time and at all times thereafter during the term of
years therein mentioned, should and lawfully might make, use, exercise, and
vend, within that part of the United Kingdom of Great Britain and Ireland,
called England, Her Majesty's Dominion of Wales, and Town of Berwick-upon-
Tweed, and in Her Majesty's Islands of Jersey, Guernsey, Alderney, Sark,
and Man, and also in all Her Majesty's Colonies and Plantations abroad, my
Invention of "AN EXPEDITIOUS MODE OF UNHAIRING, MASTERING, AND TANNING
VARIOUS DESCRIPTIONS OF HIDES AND SKINS;" in which said Letters Patent there
is contained a proviso, that I, the said James Furnival, shall 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, to be enrolled in Her said Majesty's High Court of Chancery within four

page_text: alendar months next and immediately after the date of the said Letters
Patent, as by reference to the said Letters Patent will more fully and at large
ppear.
NOW KNOW YE, that in compliance with the said proviso, I, the said.
James Furnival, do hereby declare that the nature of my Invention, and the
manner in which the same is to be performed, are particularly described and
scertained in and by the following instrument in writing, reference being
made to the Drawing in the margin.
Unhairing.
In the method of unhairing now generally in use,
the hides and skins are put into pits containing the
liquor used for that purpose, and taken out and put
in again as often as the tanner thinks proper, which
in few instances is more than once each day, and in
others once in three days: this is all done by manual
labour. In my method, after they are put into the
apparatus they are kept in motion by power; thus
a great saving is effected of time and manual labor.
The mastering, both in the old and new systems, is the same as the un-
airing.
Mastering.
Tanning.
In the method of tanning now generally in use the pits containing the hides
and skins are of two different kinds, namely, handlers and lays; the handlers
re arranged in sets, generally about six in the set, all having liquor of a
lifferent strength, the weakest of which is the tann liquor, that the pelts are
irst put into after being unhaired and mastered, and to which they are handled,
hat is, taken out and put in again two or three times each day, until they are
what is termed in the trade grained, or the outer surface regularly coloured,
fter. which they are only handled once each day up to a certain stage, when
hey are moved into the lay pits, where they are not often disturbed. Some
anners handle their light goods until they are tanned, and do not move them
nto their lay pits at all.
"
The graining of the goods is done by some tanners in strong liquors before
hey go into the handlers; others use with strong liquor the same apparatus
hat I use for thoroughly tanning them; this is done in both instances to save
he trouble and expence of handling their packs more than once each day.
My system saves all this handling and moving, for after the goods are put into
he apparatus they need not be moved until they are tanned, except in the case
of horse hides, which in my system must be tanned whole, to prevent their
wisting and knotting in the, vessel, and the butts, if not sufficiently tanned
when the hides are taken out, must be cut out, and subjected to a second

page_text: operation in the vessel. In Mr. Cox's system, the hides and skins are moved
from one pit to another by means of a series of rollers.
The chief advantages resulting from my system are a saving of time and
manual labor, the former being only about one-fifth of that required in
tanning by the old method; a consequent saving of about four-fifths of the
capital necessary for the same weight of leather, and the production of a much
superior article.
My Invention consists in the application, during the processes of unhairing,
mastering, and tanning all foreign and English ox, cow, horse, and other hides,
or parts of them, kips, or parts of them, calf skins above nine pounds each in
the green state, and hog and seal skins by means of a tub, vat, or other vessel,
or any number of such vessels into which the usual liquors used by tanners aré
introduced, and which tub, vat, or other vessel is made to revolve upon an
axis, and is secured at each end by screw bolts. In the inside are longitudinal
beams, placed so as to cause an uneven motion in the liquors contained in the
vessel. The hides and skins are put into the vessel through a hole in the side,
closed by a lid and secured by iron bolts or wedges. In the operations of
unhairing and mastering, this vessel must either bo an open frame work
through which the liquors may freely pass and repass, or the hole must be à
grating and not a close lid.
The cylinder or vessel may be made either of wood or metal for this depart-
ment of the business, but the longitudinal beams inside should be placed in a
slanting direction, which will be better understood by the accompanying Figure,
(a diametrical section of the cylinder, shewing the ends of the beamis,) but it is
immaterial whether they are placed in this form or as the dotted lines show in
the same Figure. These beams may be about nine inches wide or wider if therò
be sufficient power to turn them, for the wider the beams are, the more power
will be required. The cylinder or vessel should revolve round its axis abont
ten times a minute, unless the the vessel be a mere open frame work. The hole
in the side of this apparatus, through which the hides are put, must be closed
by bars or grating, so as to prevent the hides coming out, but at the same time
admit into the apparatus the free entrance of the atmospheric air. This
apparatus during the unhairing is to revolve in a pit or other convenient place,
so that two-thirds of it may be under the liquor used in unhairing, whether a
solution of lime or any other liquor be used for this purpose, and which must
be used in the same manner and in the same proportions as are now used in the
trade.
The same apparatus as described above, only instead of the cylinder or vessel
revolving round its axis about ten times a minute it must only revolve two or

page_text: three times a minute; similar liquors are to be used to those which are now
used in the trade for this purpose. It is of no consequence whether the above
apparatus be a close made cylinder or composed of ribs or bars.
I have previously described the apparatus for this department of the trade,
and have specified the description of goods for the thoroughly tanning of which
I claim the right of this apparatus, and I think there is nothing more to be
explained than the method by which the apparatus is made applicable for
tanning that description of goods:
There is no method sufficiently easy or expeditious now practised in the
trade, by which to know the quantity of tannin contained in any given quantity
of liquor, but as it is very necessary in this method of tanning that the strength
should in some measure be known, it may be very easily and sufficiently ascer-
tained by taking the specific gravity of the liquor. I have used for this purpose
the tanometer made by Messieurs I. & I. Ronchelli, No. 43, Market Street,
Manchester. In tanning with extracts to produce a good and clean article, it
would be well not to use the liquors heavier than "thirty" as marked on the
'scale of the tanometer, and not to allow the liquors to remain without renewing
them when they become lighter than "eight;" after dissolving the extract
in water or weak liquor it should be allowed to settle and only the clear liquor
used.
In tanning with oak, or any other bark, the apparatus must be arranged into
sets for the convenience of spending the liquor, and the liquor should be moved
in the same manner as the packs are now moved in the handlers, namely,
running off the weakest liquor from the youngest pack to be removed, and
moving the other liquors from one to the other, so as to make room for a fresh
strong liquor to the oldest pack; and to save pumping, the vessels of the
apparatus may either be placed one over another if there be convenience, so as
the more easily to run the liquors from an upper to a lower pack, or a
communication may be made through the axes of the series of tubs, admitting
the strongest liquor to the oldest pack, and thence circulating it through the
others until it runs out from the youngest pack into the old leck. There
should not be more than six packs in the set, but one pack may be used by
itself with as much ease as six, for if a green pack be put in with a strong
liquor, the goods will not be at all damaged if the power be applied imme-
diately and the action continued for about six hours afterwards. Strict
attention is required to the strength of the liquors with the youngest packs,
and as the specific gravity of the liquor in different tan yards differs much, the
best and surest guide for any tanner who may practice this method of tanning
is to take the specific gravity of his weakest handler, and never suffer the

page_text: weakest liquor in the revolving apparatus to remain after it becomes the same
weight with it. The principal cause of this difference of weight in the liquors
in different yards is the different systems of tanning, some tanners running
away their old handlers and replacing them with water, and others renewing
them in the former the weight of the liquor may be allowed to sink to "five,"
but in the latter not lower than "ten."
In tanning with.extracts, I have used as an assistant to the combination the
purified acetic acid, obtained from the destruction distillation of wood, about
two pounds of the concentrated acetic acid, as retailed by the druggist to five
hundred pounds of tanned leather, but if the liquors become very acid, as they
will under some circumstances, this supply of acid must be diminished or
discontinued. The taste will indicate whether the acid is in excess.
It will
be dangerous to use the acid if the strength of the liquors be not kept up.
In witness whereof, I, the said James Furnival, have hereunto set my
hand and seal, this Tenth day of July, in the year of our Lord One
thousand eight hundred and forty-one.
Inrolled the Thirteenth day of July, in the year of our Lord One thousand
eight bundred and forty-one.