IMPROVEMENTS IN TANNING HIDES AND SKINS, AND IN CURRYING LEATHER
Year: 1866

page_text: LETTERS PATENT to George Tomlinson Bousfield, of Loughborough Park,
Brixton, in the County of Surrey, for the Invention of "IMPROVEMENTS
IN TANNING HIDES AND SKINS, AND IN CURRYING LEATHER."-A communi-
cation from abroad by Moses Webster Page, residing at Franklin, in
the County of Merrimac, and State of New Hampshire, United States
of America.
COMPLETE SPECIFICATION filed by the said George Tomlinson Bousfield
at the Office of the Commissioners of Patents, with his Petition ani
Declaration, on the 31st May 1866, pursuant to the 9th Section of
the Patent Law Amendment Act, 1852.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, GEORGE
TOMLINSON BOUSFIELD, of Loughborough Park, Brixton, in the County of
Surrey, do hereby declare the nature of the Invention for "IMPROVEMENTS IN
TANNING HIDES AND SKINS, AND IN CURRYING LEATHER," (communicated to me
from abroad by Moses Webster Page, a person resident at Franklin, in the
County of Merrimac, and State of New Hampshire, United States of
America,) and in what manner the same is to be performed, to be particularly
described and ascertained in and by the following statement thereof, that is
to say-

page_text: The first part of the Invention consists in an improved process of tanning
hides and skius, whereby the fibres are closely united or condensed and caused
to lie compactly together, thus greatly increasing the strength and toughness
of the leather, while at the same time it is rendered pliable, which process
adapts it particularly for "lace leather" and for other purposes where great
strength and toughness combined with pliability are required. The hides or
skins to be tanned are first worked and softened in the usual manner when
they are placed in a weak solution of lime for one or two days, after which
they are placed in a strong solution of lime and "limed light." When well
"limed" they are "unhaired" and "drenched" quickly and thoroughly in a
solution of hen manure or other suitable preparation so as to entirely remove
all the lime; they are then immersed in a coloring liquor made from equal
parts of any suitable bark and "sweet fern," "cutch" and "sweet fern," or
"gambir" and "sweet fern," where they remain from three to six days, during
which time they are frequently handled first in weak and afterwards in strong
liquor; they are then removed and thoroughly worked both on the flesh and
"grain" sides, after which they are treated in the following manner :-I take
40 parts or pounds of common salt (chloride of sodium) or an equivalent of
chloride of potassium, ammonium, or other chloride soluble in water; 40 parts
or pounds of alum (either potash, soda, or amonia, alum, or sulphate of
alumina), cr an equivalent of a soluble aluminous salt, and 18, parts or
pounds of saltpetre, or an equivalent of soda, or ammonia, saltpetre, or soluble
nitrate of the earth's, and mix them thoroughly. I dissolve this mixture in
four vats which measure about six feet by four feet, and four feet deep, half
filled with water, using for vats Nos. 1 and 2 two-thirds the weight of the
mixture necessary to make the liquor in vats Nos. 3 and 4 saturated.
Thus
if vats Nos. 3 and 4 require 300 lbs. for producing saturation I place 200 lbs.
only in vats Nos. 1 and 2; this forms my "salt solution;" I then dip from
vat No. 4, 2 gallons of salt solution into a tub and add to it 2 quarts of oil of
vitriol, 2 gallons of muriate of tin of 140° to 150° T. strength, or an equivalent
of cbrystals of tin or any soluble salt of protoxide of tin, 2 gallons of muriatic
acid of 20° to 23° B. strength, and 2 gallons of nitric acid of 36° or 40° B.
strength. I prefer to form my the solution in this way, but I can use instead
of muriatic acid nitric acid and muriate of tiu, 6 gallons of oximuriate of tin
120° T. strength, or 8 gallons of a hot solution of pink salt (double chloride of
tin and ammonium), the mixture being made by stirring at the time of each
addition; the liquor may then be transferred to a carboy and preserved as the
"tin solution." I then take one pint of this tiu solution and put it into each
of the vats, Nos. 3 and 4, containing the salt solution first described, thus

page_text: making the mixture in these latter vats of a greater strength as required, each
of the four vats being capable of immersing about 100 sides of hides or 150
calf skins; and one pint of this tin solution is put into each of the vats
Nos. 3 and 4 every time a new lot of hides is placed therein. The hides or
skins are now immersed in vat No. 1 where they are allowed to remain about
four hours, when they are removed and immersed in vat No. 2 for about five
hours, then in vat No. 8 for about soven hours, and in vat No. 4 for about
eight hours (in all about twenty-four hours); they are then removed and well
worked both on the "flesh" and "grain" sides, after which they are curried
and finished. The above described process of tanning condenses the hides and
skins and causes the fibres to be brought compactly together, thus greatly
increasing the strength and toughness of the leather, while at the same time it
is rendered soft and pliable when finished, thus particularly adapting it for
"lace leather," picker or harness straps for looms, or for extremely thin and
narrow machine belting; this process, however, is also well adapted for tanning
calf, wax belting, harness, or any other variety of skin that may be desired.
I do not limit myself to the exact proportions above described, or to the
precise time which the hides are immersed in the various solutions, as they
may be varied somewhat to suit different kinds or grades of leather without
departing from the spirit of my Invention. In practise, however, I have found
the proportions and time above spoken of to answer well. In the coloring
process first described the "sweet fern" may be entirely dispensed with, if
preferred, and a coloring liquor made either of bark, "cutch," gambir," or
other suitable tanning material be employed instead, or the "sweet fern" may
be employed alone, if desired, but the liquor first described I consider to be
the best.
The second part of the Invention consists in certain improvements in the
process of currying leather, which I will now proceed to describe. In the
ordinary process of currying leather, after the usual "skiving" operation has
been performed, the leather has been shaved off chiefly on the flesh side of the
"but" in order to reduce it to the uniform thickness required. As however
the flesh side of the leather is much stronger than the " grain" side, the
quality of tho stock is thereby depreciated, and for the purposes of "lacing"
picker or harness straps for looms, and where very thin and narrow machine
belting is required this process of currying is particularly objectionable on
account of the leather being weakened; this part of the Invention therefore
has for its object to avoid these objections, and consists in "buffing" or
shaving chiefly the "grain" side, instead of shaving the flesh side of the "but "
of the leather, whereby it may be brought more nearly to a uniform thickness

page_text: "
"
without impairing its strength, and requiring but little "levelling
on the
flesh side, while its softness and pliability are very much increased. The
leather to be curried after having been properly tanned is skived in a well-
known manner, when it is "buffed" or shaved very lightly entirely over the
grain" side, and then the "but" or thick part is shaved nearly through the
grain" by taking off several more cuts or clips, so as to reduce its thickness
very considerably, by which means the leather is brought more nearly to a
uniform thickness, thereby requiring but little "levelling" or shaving on the
flesh side of the "but." While the operations of "skiving" and "buffing"
are proceeding, great care should be taken that the stock does not dry, thus
avoiding the use of water which, if applied before the oil or "stuffing" would
occasion considerable damage to the leather. The leather is now ready for
the "stuffing" which is composed of the following ingredients in about the
following proportions, viz. :-8 lbs. of tallow, 8 qts. of cooked cod-liver oil
(rejected medicine oil), 8 qts. refined "petroleum," such as is used by
curriers; 4 qts. neatsfoot oil mixed and applied as usual.. The leather
should now be dried in the shade and packed down for a few days, when
it is "pin blocked," "boarded," or otherwise softened as most convenient
and "glassed" sufficiently to give it a smooth and finished appearance. Wax
leather, calf skins, and leather for harness and heavy belting should be
"buffed " very lightly over the "grain," and the wax leather and calf skins
are blacked on the flesh side in the following manner :-Soap blacking after
being made about a month is used in small quantities, and the stock being
well cleaned is left to dry for fifteen or twenty minutes, when the cooked
cod liver oil is applied, and after the oil has "struck in" or "out of
sight" the leather is immediately "glassed," giving it the appearance of
a French finish. The leather used for harness is blacked in the ordinary way.
By "buffing" the leather to be used for "lacing," etc., in the manner and
on the "grain" side, as above described, the hardness of tho "grain" is
removed, and the "but" or thick portion reduced to a uniform thickness
with the remaining portion without impairing the strength of the leather.
In the preparation of the above described "stuffing" I find the cooked cod-
liver oil to be a valuable ingredient, as it renders the leather exceedingly soft
and pliable, which on this account is especially adapted for "lacing
"picker or
harness straps for looms, and for thin and narrow machine belting, while it
answers well for all other descriptions of leather in common use; such cooked
oil containing less sediment, and being therefore less liable to gum up or dry
out of the leather than the oil now in general use, and preventing the leather
from becoming hard and "husky" when worn.

page_text: Having now set forth the nature of this Invention, and explained the
manner of carrying the same into effect, I wish it to be understood that under
the above recited Letters Patent I claim,→
The within-described process of tanning bides and skins, substantially as
set forth.
Second, I claim as an improvement in currying leather "buffing" the
grain "side instead of shaving the "flesh" side of the "but" of thick
portion of the leather, substantially as and for the purpose set forth.
In witness whereof, I, the said George Tomlinson Bousfield, have here-
unto set my hand and seal, this 16th day of May, in the year of our
Lord 1866..