CERTAIN IMPROVEMENTS IN USING MATERIALS EMPLOYED IN TANNING, AND PREPARING THE SAME FOR OTHER USEFUL PURPOSES
Year: 1839

page_text: TO ALL TO WHOM THESE PRESENTS SHALL COME, I, FRANCIS
BREWIN, of the Old Kent Road, in the County of Surrey, Tanner, send
greeting.
WHEREAS Her most Gracious Majesty Queen Victoria, by Her Letters
Patent under the Great Seal of Great Britain, bearing date the Eleventh day
of January, One thousand eight hundred and thirty-nine, did, for Herself,
Her heirs and successors, give and grant unto me, the said Francis Brewin,
Her especial licence, that I, the said Francis Brewin, my exors, admors,
and assigns, or such others as I, the said Francis Brewin, 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, within England, Wales, and the Town of
Berwick-upon-Tweed, and in all Her Majesty's Colonies and Plantations
abroad, an Invention made by me of "CERTAIN IMPROVEMENTS IN USING
MATERIALS EMPLOYED IN TANNING, AND PREPARING THE SAME FOR OTHER USEFUL
PURPOSES;" in which said Letters Patent there is contained a proviso, that I,
the said Francis Brewin, shall, by an instrument in writing under my hand
and seal, particularly describe and ascertain the nature of the said Invention,
and the manner in which the same is to be performed, and cause the same to

page_text: be inrolled in Her Majesty's High Court of Chancery within six 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
Francis Brewin, do hereby declare that the nature of my said invented
improvements in using materials employed in tanning, and preparing the same
for useful purposes, consists in applying mechanical pressure to the said
materials after they have been used in the common way, but before they have
been spent or exhausted to such a degree as is ordinarily done, whereby I
effect these several objects:-Firstly, I keep the liquors in the taps, spenders,
and vats, generally of greater strength than is done by following out the com-
mon process to its full extent; secondly, I obtain a greater quantity of tanning
materials than is generally extracted by liquid immersion merely; thirdly, the
process of tanning is completed in a less time; and, fourthly, the refuse
materials, after they have so been compressed, are left in a state and form fit
for immediate use as fuel for steam engine and other furnaces, and require
but little, if any more, drying to be used in common house stoves. And I
declare that the manner in which the said improvements are performed is as
follows:-
After the tanning materials have been used in the common way, but before
they have been so much spent as usual, they are taken out of the pits and put
into a strong box or case of three feet six inches in depth, in successive layers
of about four inches in thickness, with thin iron plates interposed between
them, for the purpose of being subjected to the mechanical pressure before
mentioned. First, one layer is put into this compressing box, and made even
and pressed down by hand by means of a flat piece of wood with a handle,
after which a thin plate of iron is placed above or upon that layer; then layer
after layer of the tanning materials is added, spread, and pressed down,in like
manner as the first, with iron plates interposed between, till the compressing
box is full, so far as the gravity of the materials or hand pressure can make it.
The workman or workmen employed in filling the box or press (more than
two will seldom be requisite) then mount upon the topmast iron plate, and by
his or their weight cause such a compression of the contents of the box or case
that room is gained for the addition of some more of the tanning materials.
I now apply to the entire contents of the compressing box the power of a
hydraulic press having a strong ram affixed to the under part of the top of
the press of such square area that it will just enter the box, but is only. about

page_text: three quarters as long as the box is deep. The exact length to be given to
this 'ram will depend upon the nature of the tanning materials employed, as,
for example, young bark will sink more in pressing than old thick bark; but
in any case the length of this ram must be such as to prevent the box from
being forced against the top of the press. For the purpose of running off the
tanning liquor squeezed out of the materials so subjected to pressure the inside
of the box is ribbed or grooved both at the sides and ends, the grooves are
about three-quarters of an inch apart, eacli groove is about one inch in width,
three-quarters of an inch in depth, and covered over with a thin iron plate
perforated with holes for the liquor to pass through into the grooves, while to
let off the liquor from the grooves there are holes in the exterior of the box
opening into the sides of the grooves, and one at the bottom of each groove,
and from all these exterior holes the liquor is conveyed to a.vat or. reservoir.
The liquor thus obtained I pass through the spenders and taps, as by this
means the tanning liquor may be conveniently made of any desirable strength,
and at the same time it assists to spend the bark. I liave herein-before directed
the tanning materials to be taken out of the pits before they are as much
spent as usual, considering that to be generally the best plan, but I do not limit
my process to materials in that state, for to whatever extent they may be
exhausted in thé pits by the common process, an additional quantity of tanning
liquor may still be extracted from them by subjecting them to mechanical
pressure in the manner before described; neither do I limit my process
to pressing the materials immediately they are taken out of the pits. I also
press them for the purpose of fuel only when in a decayed state, or at any
time after they have been used by the tanner; but when the tan is decayed,
and particularly if very wet, the box is required to be made stronger. The
materials in the box are pressed to that degree that when they are taken
out they are in a sufficiently desiccated state to be burnt in steam engine
and other furnaces, but they may be required to be more dried to fit them for
use in common house stoves, and in that case they may be set to dry much in
the same way in which tanners' turf is ordinarily dried. It is desirable to
remove the different layers or cakes, as they may be called, in the state into
which they are now compressed from the box in as entire a state as possible
For this purpose the front side of the box opens on strong hinges, and on
that side the box is also made two inches wider, than in any other part. The
front side being opened, the cakes are taken out in succession by hand with
the help of a round wooden lever shod with iron, similar in shape to a chisel,
which is introduced under each of the plates employed as before mentioned to

page_text: separate the layers or cakes. The cakes, if required to be further dried for
household purposes, are then laid on shelves of a suitable size, and between
every two cakes are placed four pieces of common wooden lath, nailed together
in the shape of an oblong, about six inches less in width and length than the
cakes. The cakes may be made large or small, according to the power of
the press and the purposes for which they are to be used. The power I use is
equal to about two thousand pounds to the square inch, that is to say, for a
box of tanning materials thirty-four inches wide in front, thirty-two inches
wide at the back, and sixteen inches across, I make use of a hydraulic- press
of about four hundred and fifty tons power. The box may be of wood or
iron, or of wood and iron combined, but must in every case be of strength
proportionate to the pressure to be applied and to the nature of the tanning
materials. If the tanning materials have not been ground smaller than usual,
I find that a box made of three inch oak, bound with strong iron, will sustain
the pressure I generally use, namely, two thousand pounds to the square inch.
For the sake of greater dispatch, I make use of two compressing boxes one on
each side of the hydraulic press, and the more readily to move them to and
from the press, each box is placed upon a truck with four wheels, which run
on iron rails. The materials in one box are pressed while the other is filling,
and so on alternately, by which means the hydraulic press is kept almost in
constant work. The press may be either worked by a steam engine (which is
what I employ), or by water, horse, or any other adequate power.
And having now described the nature of my said invented improvements,
and the manner in which the same are to be performed, I declare that what I
claim to have exclusive right to is the application of mechanical pressure in
the manner before described, or in any other sufficient manner, to the materials
employed in tanning after the same have been used in the common way, and
more or less spent, for the purpose of extracting by such pressure the remainder
of the tannen contained in them, and reducing them at the same time into a
state and form fit for immediate use as fuel, for steam engine and other fur-
naces, and requiring only a little, if any more, drying to render them fit for use
in common house stoves, or for either of these purposes separately.
And such my Invention being to the best of my knowledge and belief new
and never before used within that part of Her said Majesty's United Kingdom
of Great Britain and Ireland called England, Her Dominion of Wales, Town
of Berwick-upon-Tweed, or in any of Her Majesty's Colonies and Plantations
abroad, I do hereby declare this to be my Specification of the same, and I do
verily believe that this my said Specification doth comply in all respects fully
and without reserve or disguise with the proviso in the said recited Letters

page_text: AND BE IT REMEMBERED, that on the Eighth day of July, in the year
of our Lord 1839, the aforesaid Francis Brewin came before our said Lady
the Queen in Her 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 Eighth day of July, in the year of our Lord One thousand
eight hundred and thirty-nine.