IMPROVEMENTS IN PRESERVING WOOD.
Year: 1855

page_text: LETTERS PATENT to Hippolyte Mathis, Negociant, of 42, Rue Notre
Dame des Victoires, à Paris, for the Invention of "IMPROVEMENTS IN
PRESERVING WOOD. —A communication from Doctor Boucherie.
Sealed the 14th December 1855, and dated the 15th June 1855.
PROVISIONAL SPECIFICATION left by the said Hippolyte Mathis at the
Office of the Commissioners of Patents, with his Petition, on the 15th
June 1855.
I, HIPPOLYTE MATHIS, Negociant, of 42, Rue Notre Dame des Victoires, à
Paris, do hereby declare the nature of the Invention for "IMPROVEMINTS IN
PRESERVING WOOD" to be as follows:-
This Invention consists in impregnating timber with a solution of sulphate
of copper in the following manner :-Soon after the tree is felled, a saw cut is
made all round the trunk of the tree, and this circular saw cut is caulked or
stopped all round its circumference in any convenient manner, and into the
space thus formed the impregnating solution is conducted by a tube from an
elevated reservoir; or the chamber at the end of the tree may be formed by
placing a washer on its end, and fixing a board against the washer by means
of a screw passing through the board and into the end of the tree. When it is
desired to impregnate timber after it has been cut up, an air-tight case divided
into a series of vertical chambers is used; into these chambers are placed the

page_text: pieces of timber to be impregnated; they are held suspended by a screw
passing through the covers of the chamber, and into the end of the piece of
timber. The impregnating liquid is let into the air-tight case from an elevated
reservoir, and after a time the impregnating liquid is shut off, and the upper
part of the case opened to the atmosphere.
SPECIFICATION in pursuance of the conditions of the. Letters Patent, filed
by the said Hippolyte Mathis in the Great Seal Patent Office on the
14th December 1855.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, HIPPOLYTE
MATHIS, Negociant, of 42, Rue Notre Dame de Victoires, à Paris, send
greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Fifteenth day of June, in the year of our Lord, One
thousand eight hundred and fifty-five, in the eighteenth year of Her reign,
did, for Herself, Her heirs and successors, give and grant unto me, the said
Hippolyte Mathis, Her special licence that I, the said Hippolyte Mathis, my
executors, administrators, and assigns, or such others as I, the said Hippolyte
Mathis, my executors, administrators, and assigns, should at any
time agree
with, and no others, from time to time and at all-times thereafter during the
term therein expressed, should and lawfully might make, use, exercise, and
vend, within the United Kingdom of Great Britain and Ireland, the Channel
Islands, and Isle of Man, an Invention for "IMPROVEMENTS IN PRESERVING
WOOD," (a communication from Doctor Boucherie;) upon the condition (amongst
others) that I, the said Hippolyte Mathis, by an instrument in writing under
my hand and seal, should particularly describe and ascertain the nature of the
said Invention, and in what manner the same was to be performed, and cause
the same to be filed in the Great Seal Patent Office within six calendar months
next and immediately after the date of the said Letter's Patent.
NOW KNOW YE, that I, the said Hippolyte Mathis, do hereby declare
the nature of the said Invention, and in what manner the same is to be per-
formed, to be particularly described and ascertained in and by the following
statement thereof (that is to say): "
This Invention consists in impregnating timber with a solution of sulphate
of copper in the following manner-Soon after tlie tréé is felled, a saw cut is
made all round the trunk of the true, and this circular saw cut is caulked or
stopped all round its circumference in any convenient manner, and into tlie

page_text: space thus formed the impregnating solution is conducted by a tube from an
élevated reservoir; or the chamber at the end of the tree may be formed by
placing a washer on its end, and fixing a board against the washer by means of
a screw passing through the board and into the end of the tree. When it is
desired to impregnate timber after it has been cut up, an air-tight case divided
into series of vertical chambers is used; into these chambers are placed the
pieces of timber to be impregnated; they are held suspended by a screw passing
through the covers of the chamber, and into the end of the piece of timber.
The impregnating liquid is let into the air-tight case from an elevated reservoir;
and after a time the impregnating liquid is shut off, and the upper part of the
case opened to the atmosphere.
... F
Having thus stated the nature of the said Invention; I will proceed more
fully to describe the manner of performing the same.
.::
DESCRIPTION OF THE DRAWING:
}
Figure 1 shows a piece of timber with a saw cut; Figure 2 shows a section,
taken at a, a, in Figure 1. The saw cut thus made is caulked at the outer
circumference, so as to leave a narrow space between the uncut central portion
6 and the outer circumference, where it is caulked at a, a. An inclined hole
is formed at c, into which the end of the tube d is inserted. This hole pene-
trates into the saw cut, and conducts preserving fluid (by preference a solution
of sulphate of copper such as heretofore used) thereto. The tube'd commu-
nicates with a reservoir above, and it is preferred that there should be a
columnal pressure of about twenty-five feet; but this may be varied. In a short
time it will be found that the sap will begin to exude from the two ends of the
timber, which will in time be followed by the preserving fluid. In order to
ascertain when the solution of copper fully penetrates all parts of the timber, a
crystal of prussiate of potash is rubbed on different parts of the surface, and if
the solution has penetrated to the parts brown marks will be produced, and
"then when the solution comes out' strong the process is to be stopped. Small
trees newly felled, ten to twelve inches in diameter, may be completed in from
ten to twelve hours, but older and larger timber will require more time. In
case it 'be desired to preserve the timber without making a saw cut inter-
mediate of its length, then a similar process to that above described is resorted
to, by applying a disc or plate to one end of the timber by means of a screw'or
"screws, in which case the outer circumference is to be made fluid-tight by
caulking between the outer circumference and the-disc and the end-of-the
timber, as will be understood by reference-to-Figure 3e, is the discor
"plate of metal, or other suitable material, fixed securely by screws f, and made

page_text: fluid-tight by caulking at a, a, as before described; d being the tube introduced
into the hole c. Fig. 4 shows the general arrangement of the whole apparatus.
The above mode of displacing the sap of whole timber acts perfectly,
because as the vessels are continuous all those exposed to the pressure of the
liquid are filled therewith; but in cases where the timber is sawn up, the ends
of many of the sap vessels will be one at the side and the other at the end of
the wood; others again in cross-grained timber may have. both ends.opening
at the side of the wood for the more perfect saturation of sawn timber. I
enclose the whole piece in a tight vessel (see Fig. 5) in such manner as to
expose the superficies thereof except one end to the pressure of the preserving
fluid, this one end being open to ordinary atmospheric pressure; and after the
preserving fluid has sufficiently percolated through the sap vessels which open
at that end I reverse it, and I make the fluid percolate through the opposite
end, and thus in general the wood will be sufficiently saturated; but in case
of very cross-grained pieces, I make the water-tight junction at some inter-
mediate portion of the length, as at a, b, (Fig. 6,) so as to allow the portion
.a, b, e, f, to be exposed to the pressure of the fluid, and the parts a, b, g, h, will
be under only atmospheric pressure, and sap vessels running in the direction of
c, d, will thus become as perfectly filled with the fluid as if the grain had been
quite straight; and instead of using one vessel for each piece of wood, a large
vessel may be made with any convenient number of openings, so that the ends
of many pieces of wood may be exposed to the air, and the fluid act upon the
remaining superficies of all the pieces in common.
Having thus described the nature of the said Invention, and the manner of
-performing the same, I would have it understood that I am aware that it has
before been proposed to place wood in closed tanks, and by means of pressure
of the preserving fluid, or by exhaustion and pressure, to cause the fluid to
penetrate the wood, but in such cases the preserving fluid does not filter into
and through the wood, as above described; and I am aware that it has also
been proposed to apply preserving fluid under pressure to one end of a felled
tree or piece of timber by means of a flexible tube, and to exhaust by an
exhausted vessel, or by an air pump at the other end of the timber, in con-
nexion with a close cap or chamber fixed tightly on the other end of the piece
of timber; and I mention these in order to state that I make no claim thereto.
And I would observe, that by the means above described as constituting the
present improvements, not only is the preserving fluid made to percolate or
filter longitudinally through the wood, but the expensive apparatus necessary
for exhaustion is dispensed with; and I would also remark, that although I
have mentioned a solution of sulphate of copper as the solution which I prefer

page_text: to employ, still I do not confine myself thereto, as timber may be in a similar
manner impregnated with other solutions, if it should be thought desirable;
but what I claim, is,―
Firstly, the introduction of the preserving fluid into a cut intermediate of
the length, as described in respect to Figures 1 and 2.
Secondly, the fixing at one end of a piece of wood a disc or plate, and caulk-
ing the same, as described in respect to Figures 3 and 4, and also dispensing
with exhaustion when applying the preserving fluid at one end only of a piece
of wood.
And, thirdly, the method herein-before described of preserving sawn timber
by applying the preserving liquid under pressure to the sides and one end of
the piece of sawn timber, leaving the other end exposed to the ordinary
atmospheric pressure only.
In witness whereof, I, the said Hippolyte Mathis, have hereunto set my
hand and seal, this Sixteenth day of November, in the year of our
Lord One thousand eight hundred and fifty-five.
Witness,
JNO. ALCOCK.
H. MATHIS.
(L.S.)