IMPROVEMENTS IN TANNING HIDES AND SKINS, AND IN APPARATUS CONNECTED THEREWITH
Year: 1875

page_text: PROVISIONAL SPECIFICATION left by Alexander Melville Clark at
the Office of the Commissioners of Patents, with his Petition, on
the 10th November 1875.-A communication from abroad by Eugène
Delhort, of Marseilles, France.
I, ALEXANDER MELVILLE CLARK, of 53, Chancery Lane, in the
County of Middlesex, Patent Agent, do hereby declare the nature of
the said Invention for "IMPROVEMENTS IN TANNING HIDES AND SKINS, AND IN
APPARATUS CONNECTED THEREWITH," to be as follows:-
This Invention relates to an improved quick process of tanning hides
and skins.
In order to carry out the Invention in a regular and uniform manner,
I construct a furnace preferably of circular form externally with an
internal chamber of rectangular form. The furnace is surmounted by a
dome having a central aperture, from which rises an inverted truncated
cone to a height of about 6 to 8 inches above the dome; it is fitted to
receive a movable metal cover by which the passage may be hermetically
closed.

page_text: ⋅
From the mouth of the cone rises a chimney of stout sheet iron made
telescopic at the lower part to give access to the cone. The furnace is
well charged with pine wood, charcoal, coke, bones, oyster shells, and
calcareous substances; after these matters have been heated and
brought to an advanced state of effervescence, the telescopic chimney is
raised to enable the cone to be closed hermetically by its cover.
The gases escape through pipes leading from the dome of the furnace
into a cooling and purifying receiver of cylindrical form surmounted by
a cone, from the summit of which a pipe is led for a purpose herein-after
referred to.
Near the bottom of the receiver there is a grating made of oak, on
which is placed a layer of about 20. inches of stone reduced to about the
size of gravel, and upon this there is a depth of about 2 inches of water,
the space between the water and the summit of the cone which should
be about 3 feet being left vacant.
The cooling receiver is fitted on the outside; 1st, with a large cock at
the bottom for empyting the receiver; 2nd, a gauge cock at the water
level; 3rd, a supply cock placed on the cone. The receiver may be
capable of holding the volume of gas produced by two furnaces. The
gas is supplied to the cooling and purifying receiver at the centre
beneath the grated bottom, and becomes thoroughly purified in passing
up through the gravel and water. From the summit of the receiver
leads a pipe of sufficient diameter for the volume of gas required and
communicating with a pump, by which the gas is exhausted from the
receiver and forced into vats by a pipe leading to the centre of the
bottom of each vat, whence branches of unequal length radiate in eight
different directions in order that the whole area of the vat may be.
brought into action. The ends of the branch pipes should be covered
with fine wirework. The supply of gas for each vat is controlled by a
regulator. The vats should also be furnished with a false bottom to
prevent the pipes being obstructed by the skins.
Before the admission of the gases the hides or skins are placed in the
vats with water and tanners' bark, to which is added a proportion of old
yeast made from equal parts of rye and barley flour softened with
chloride of lime.
The hides or skins, which are unhaired in the ordinary manner, on

page_text: 5
weight.
The above treatment is sufficient for small skins, but hides require to
be passed through the pits.
The advantages of this improved process are a saving of time in
the bark used, and in labor, together with an increase in weight, and a
superior quality of the product.