IMFROVE MENTS IN THE MEANS AND APPARATUS EMPLOYED FOR TREATING TIMBER WITH ANTISEPTIC OR PRESERVATIVE FLUIDS, ALSO APPLICABLE TO OTHER PURPOSES.
Year: 1865

page_text: LETTERS PATENT to Samuel Bagster Boulton, of No. 2, Charlotte Row,
Mansion Ilouse, in the City of London, for the Invention of "IMFROVE
MENTS IN THE MEANS AND APPARATUS EMPLOYED FOR TREATING TIMBER WITH
ANTISEPTIC OR PRESERVATIVE FLUIDS, ALSO APPLICABLE TO OTHER PURPOSES.'
Sealed the 26th May 1865, and dated the 16th March 1865.
PROVISIONAL SPECIFICATION left by the said Samuel Bagster Boulton
at the Office of the Commissioners of Patents, with his Petition, on the
16th March 1865.
I, SAMUEL BAGSTER BOULTON, of No. 2, Charlotte Row, Mansion House,
in the City of London, do hereby declare the nature of the said Invention for
"IMPROVEMENTS IN THE MEANS AND APPARATUS EMPLOYED FOR TREATING TIMBER
WITH ANTISEPTIC OR PRESERVATIVE FLUIDS, ALSO APPLICABLE TO OTHER PURPOSES," to
be as follows:-
The impregnation of timber with antiseptic or preservative fluids is generally
effected by placing such timber in a strong iron vessel, ordinarily of a cylindrical
form, from which the air is first exhausted, and into which the antiseptic fluid
is then forced under such a pressure as to cause it to penetrate into the wood.
Some antiseptic fluids, such as sulphate of copper and corrosive sublimate, are
of such a nature as to act injuriously upon and destroy the vessel in which the
operation is carried on, if such vessel is of iron, whilst if the vessel is made of
[Price 8d.]

page_text: copper, zinc, or other materials upon which the fluid does not act, it is either
too weak to withstand the pressure, or, if made sufficiently strong, the vessel
would be of so costly a nature as greatly to limit its employment.
Now my Invention has for its object to render iron vessels available when
such corrosive fluids are employed, by not introducing the fluid directly into
the iron vessel, but into another vessel made of materials such as wood, copper,
zinc, or india-rubber, upon which the fluid has little or no injurious effect,
into which vessel the timber is placed, and which is then introduced into the
iron vessel. As such inner vessel, which is by preference made of wood on
account of cheapness, is not of sufficient strength to withstand any great degree
of internal or external pressure, I proceed to operate in the following manner :-
After placing the timber in the inner vessel and closing the same in an air-
tight manner, I introduce it into the outer vessel, where I establish separate
communications, by means of pipes, between the interior of each of the vessels,
and an air pump for exhausting the air, and I then close the outer vessel
hermetically. By now exhausting simultaneously from both the inner and
outer vessel it will be seen that the pressure will decrease in a uniform
manner upon both the inside and the outside surfaces of the inner vessel, so
that the timber contained in the same may be subjected to the action of a
vacuum without the vessel having for that purpose to withstand any external
pressure.
In order now to subject the timber to the action of the antiseptic fluid under
pressure, I establish communications between the interior of the inner vessel
and a reservoir containing such fluid, and between the outer vessel and a
reservoir containing water, or any other fluid that has no injurious effect upon
the outer vessel, when on account of the vacuum existing in the vessels the
pressure of the atmosphere will cause them to be filled with such fluids. I
then force in more of the fluid and of the water respectively into the inner
and outer vessels by means of two separate pumps, until the pressure in each
vessel has attained the maximum pressure to which it is required to subject
the timber, such pumping in of the fluid and water being effected in such a
manner that the pressure increases equally, or nearly so, in both vessels,
whereby it will be seen that as the pressure upon the internal surfaces of the
inner vessel is always balanced by the pressure upon its external surfaces, the
vessel will not be injured thereby. The equal increase of pressure in cach
vessel may be insured by means of pressure gauges connected thereto, and by
regulating valves upon the feed pipes, safety valves being also provided to
each vessel, loaded to the same maximum pressure; or I cause each feed
pipe to communicate respectively with one end of a cylinder, in which is a

page_text: piston, or two pistons connected together, capable of sliding to and fro, and
according as the pressure in the one feed pipe somewhat exceeds that in the
other, the piston on being moved by such excess of pressure is caused more
or less to uncover one of two apertures in the cylinder, through which the
excess of fluid or gas escapes, thus equalizing the pressure. Or again, the two
vessels having been filled with fluid and water by the atmospheric pressure or
by pumping, I then establish a communication between them and two other
vessels, similar in arrangement to the "accumulators" employed for hydraulic
cranes, which are both loaded to the same maximum pressure, and into which
accumulators respectively antiseptic fluid and water are forced by means of
pumps. When the inner vessel containing the timber to be acted upon is not
closed at top, or is provided with a loose cover, I first exhaust the air from
both vessels, simply by connecting the outer vessels with the air pump, and I
then cause both vessels to be filled respectively with the fluid and water by
the aid of atmospheric pressure, or by pumping, until such fluid and water
have risen to the level of the upper edge of the inner vessel; after which I
force into the remaining space left in the outer vessel, air, steam, or gas, until
it has attained the pressure to which. it is required to subject the material in
the internal vessel. Or in some cases I fill only the internal vessel with the
fluid, and at the same time I force air, steam, or gas into the outer vessel
until it has attained the requisite pressure. Such employment of steam, com-
pressed air, or gas may also be rendered useful by communicating heat to the
antiseptic fluid at the same time that the pressure is exerted.
It will be evident that the before-described Invention may also be employed
with advantage in all cases where it is required to subject substances contained
in vessels of limited strength to the action either of a vacuum or of fluids or
gases under pressure.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Samuel Bagster Boulton in the Great Seal Patent Office
on the 16th September 1865.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, SAMUEL
BAGSTER BOULTON, of No. 2, Charlotte Row, Mansion House, in the City of
London, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Sixteenth day of March, in the year of our Lord
One thousand eight hundred and sixty-five, in the twenty-eighth year of

page_text: Her reign, did, for Herself, Her heirs and successors, give and grant unto me,
the said Samuel Bagster Boulton, Her special licence that I, the said Samuel
Bagster Boulton, my executors, administrators, and assigns, or such others as
I, the said Samuel Bagster Boulton, 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 "Im
PROVEMENTS IN THE MEANS AND APPARATUS EMPLOYED FOR TREATING TIMBER WITH
ANTISEPTIC OR PRESERVATIVE FLUIDS, ALSO APPLICABLE TO OTHER PURPOSES," upon
the condition (amongst others) that I, the said Samuel Bagster Boulton, my
executors or administrators, by an instrument in writing under my, or their, or
one of their hands and seals, should particularly describe and ascertain the
nature of the said Invention, and in what manner the same was to be per-
formed, 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 Letters
Pateut.
NOW KNOW YE, that I, the said Samuel Bagster Boulton, do hereby
declare the nature of the said Invention, and in what manner the same
is to be performed, to be particularly described and ascertained in and by the
following statement thereof, reference being had to the accompanying
Drawings, and to the figures and letters marked thereon, that is to say:-
The impregnation of timber with antiseptic or preservative fluids is generally
effected by placing such timber in a strong iron vessel, ordinarily of a cylindrical
form, from which the air is first exhausted, and into which the antiseptic fluid
is then forced under such a pressure as to cause it to penetrate into the wood.
Some antiseptic fluids, such as sulphate of copper and corrosive sublimate, are
of such a nature as to act injuriously upon and destroy the vessel in which the
operation is carried on, if such vessel is of iron, whilst if the vessel is made of
copper, zinc, or other materials, upon which the fluid does not act, it is either
too weak to withstand the pressure, or if made sufficiently strong the vessel
would be of so costly a nature as greatly to limit its employment.
Now my Invention has for its object to render iron vessels available when
such corrosive fluids are employed by not introducing the fluid directly into the
iron vessel, but into another vessel made of materials such as wood, copper, zinc,
or india-rubber, upon which the fluid has little or no injurious effect, into which
vessel the timber is placed, and which is then introduced into the iron vessel.
As such inner vessel, which is by preference made of wood on account of cheap-
ness, is not of sufficient strength to withstand any great degree of internal or

page_text: external pressure, I proceed to operate in the following manner :-After
placing the timber in the inner vessel and closing the same in an air-tight
manner, I introduce it into the outer vessel, where I establish separate com-
munications by means of pipes between the interior of each of the vessels and
an air pump for exhausting the air, and I then close the outer vessel hermetically,
By now exhausting simultaneously from both the inner and outer vessel it will
be seen that the pressure will decrease in a uniform manner upon both the
inside and outside surfaces of the inner vessel, so that the timber contained in
the same may be subjected to the action of a vacuum without the inner vessel
having for that purpose to withstand any external pressure.
In order now to subject the timber to the action of the antiseptic fluid under
pressure, I establish communications between the interior of the inner vessel
and a reservoir containing such fluid, and between the outer vessel and a
reservoir containing water or any other fluid that has no injurious effect upon
the outer vessel, when on account of the vacuum existing in the vessels the
pressure of the atmosphere will cause them to be filled with such fluids. I
then force in more of the fluid and of the water respectively into the inner and
outer vessels by means of two separate pumps, until the pressure in each vessel
has attained the maximum pressure to which it is required to subject the
timber, such pumping in of the fluid and water being effected in such a
manner that the pressure increases equally, or nearly so, in both vessels,
whereby it will be seen that as the pressure upon the internal surfaces of
the inner vessel is always balanced by the pressure upon its external surfaces,
the vessel will not be injured thereby. The equal increase of pressure in each
vessel may be insured by means of pressure gauges connected thereto, and by
regulating valves upon the feed pipes, safety valves being also provided to each
vessel loaded to the same maximum pressure; or I cause each feed pipe to
communicate respectively with one end of a cylinder in which is a piston, or
two pistons connected together, capable of sliding to and fro; and according
as the pressure in the one feed pipe somewhat exceeds that in the other, the
piston on being moved by such excess of pressure is caused more or less to
uncover one of two apertures in the cylinder, through which the excess of
fluid or gas escapes, thus equalizing the pressure. Or again, the two vessels
having been filled with fluid and water by the atmospheric pressure or by
pumping, I then establish a communication between them and two other
vessels, similar in arrangement to the "accumulators" employed for hydraulic
cranes, which are both loaded to the same maximum pressure, and into which
accumulators respectively antiseptic fluid and water are forced by means of
pumps. When the inner vessel containing the timber to be acted upon is not

page_text: closed at top or is provided with a loose cover, I first exhaust the air from
both vessels simply by connecting the outer vessel with the air pump, and I
then cause both vessels to be filled respectively with 'the fluid and water by the
aid of atmospheric pressure, or by pumping until such fluid and water have
risen to the level of the upper edge of the inner vessel; after which I force
into the remaining space left in the outer vessel, air, steam, or gas, until it has
attained the pressure to which it is required to subject the material in the
internal vessel. Or in some cases I fill only the internal vessel with the fluid.
and at the same time I force air, steam, or gas into the the outer vessel until
it has attained the requisite pressure. Such employment of steam, compressed
air, or gas may also be rendered useful by communicating heat to the antiseptic
fluid at the same time that the pressure is exerted.
It will be evident that the before-described apparatus may also be employed
with advantage in all cases where it is required to subject substances contained
in vessels of limited strength to the action either of a vacuum or of fluids or
gases under pressure.
Figures 1 to 4 on Sheet I. of the accompanying Drawings show the
arrangement of apparatus which I prefer to employ for carrying my Invention
into practice. Figure 1 shows a longitudinal section through the same;
Figure 2 shows a plan, Figure 3 shews a transverse section, and Figure 4
shows an enlarged sectional plan of the air pump. Similar letters of reference
indicate similar parts in each of these Figures.
In this arrangement the receptacles or tank trucks A, A, A, containing the
wood to be acted upon are open at the top, the apparatus being made to act
according to the second mode herein-before described. For this purpose the tank
trucks, after being filled with wood, are wheeled into the cylinder B through
the end C, which is then closed in an air-tight manner. The cylinder B
communicates by means of pipes D, D', D2, with the air pump E, worked
from a steam engine by means of gearing F, which pump is made, by the
arrangement of valves and cocks to be hereafter described, to act as both an
exhausting and condensing air pump. The cylinder B communicates further-
more by means of the pipe G, provided with a cock or valve H, with the
water tank I, whilst other pipes J, J, J, also provided with cocks or
valves K, K, K, pass from the tank L containing the antiseptic fluid through
the top of the cylinder B in such positions that their apertures are imme-
diately above the open tops of the tank trucks A, A, A. From this arrange-
ment it will be seen that if after the tank trucks are placed inside the cylinder,
and the latter is closed as described, the air is exhausted from the cylinder B,
and consequently also from the tank trucks by means of the pump E, the

page_text: valves H and K being closed, and if these valves are then opened the pressure
of the atmosphere will cause water to pass from the tank I into the cylinder B,
and antiseptic fluid from the tank L into the tank trucks A, A, A; this is
allowed to continue until the water and antiseptic fluid have risen to within a
short distance of the upper edges of the tanks A, as indicated at Figures 1 and 2,
such level of the fluids being observed by means of the level gauges M, M, M,
and N, of which M, M, M, communicate with the interior of the tanks A by
means of a piece of flexible tubing O fixed to the tanks after they have been
placed inside the cylinder, while the gauge N communicates with the cylinder B.
When the fluids have attained the level before mentioned the valves II and K
are closed, and air is now forced by the pump E into the remaining space in
the cylinder B until the pressure is attained to which it is required to subject
the antiseptic fluid in the tanks A, in order thoroughly to impregnate the
timber with it. This pressure is observed by means of a pressure gauge
attached to the cylinder B, which is also provided with a safety valve P for
preventing the pressure attaining a dangerous degree.
The arrangement of the pipes D, D', D2, and valves Q, Q, Q, Q', of the
pump E, in order to enable it to act both as an exhausting and condensing air
pump, is as follows: The pump E has at each end a suction valve R', R,
and a delivery valve S1, S2, of which the suction valves communicate with the
pipe D', while the delivery valves communicate with the pipe D. If now the
valves Q and Q are closed and the valves Q³ and Q' are opened, air will be
drawn into the pump from the cylinder B through the pipe D' and the suction
valves R', R3, and will be expelled into the atmosphere through the delivery
valves S', S3, and through the open end of the pipe D. If, on the other hand,
the valves Q', Q, are opened and those Q3, Q. are closed, then air will be
drawn in through the open end of the pipe D', and will be forced into the
cylinder B.
As from the pressure exerted as above described the antiseptic fluid
becomes absorbed by the timber in the tanks A, it follows that if the fluid
only just covered the timber in the tanks before the pressure was exerted, then
by the sinking of the level of such fluid, consequent on its obsorbption by the
timber, the upper pieces of timber would to a certain extent become uncovered
by the fluid, and would therefore not be thoroughly impregnated. To prevent
this construct the tanks A with a rim T round the opening, which as the
timber is not filled in beyond the opening of the tank will in most cases
contain as much fluid as will be absorbed by the timber when the pressure
sink below the top of the
is exerted, so that the level of the fluid will not
timber. Should, however, the timber be so porous as to absorb a greater

page_text: quantity of fluid than is afforded by this means, then a small force pump is
connected to the air pump E, and worked by the same gear, and is made to
communicate both with the reservoir of antiseptic fluid and with each of the
tanks in such a manner that when air is being forced into the cylinder B by
the air pump antiseptic fluid is at the same time forced into the tanks A to
such an extent as to replace the quantity that is absorbed by the timber.
When the timber has been sufficiently impregnated with the antiseptic fluid
the valve H in the pipe G is opened, and the water is allowed to run out of
the cylinder B, which will be accelerated by the action of the compressed air
in the same.
The end C of the cylinder is then removed, and the tank
trucks A are run out upon a staging, not shown on the Drawing, where the
antiseptic fluid is removed from them through a cock U opening into the funnel
mouth of a pipe V, through which the fluid is conducted back into the tank L.
In order to avoid so great a loss of capacity as is the case when rectangular
tanks are employed as described, these may be constructed with curved sides,
but I prefer in that case to construct them of india-rubber, as shewn in
enlarged transverse section and sectional plan at Figures 5 and 6, Sheet II.,
of the Drawings. I form for this purpose an india-rubber receptacle W, with
curved sides and open at the top, which I place upon a carriage X, similar in
construction to that described in the Specification to certain Letters Patent
granted to H. P. Burt, bearing date the Twenty-ninth March One thousand
eight hundred and fifty-nine, (No. 788); the curved bars Y, Y, at the sides,
and flat bars Z, Z, at the ends serving as supports to the india-rubber tank;
these bars being connected together by means of links a, a, a, as shewn when
the india-rubber tank is in place. The flat bottom of the latter is supported by
boarding blaid upon the carriage; when the tank is filled with timber it is further-
more supported by the top edges of the opening being laced together as shown.
In the above-described arrangement the tank trucks are shewn of such short
lengths as are principally applicable to the preparation of sleepers or other
similar short lengths of timber, but in many cases, and especially where long
timbers are required to be prepared, it is obvious that the tank trucks must
have greater length than is shewn in the Drawings. In such cases I frequently
dispense with the wheels or iron trucks, letting the elongated tank take the
whole length of the cylinder, and in cases where an india-rubber vessel is used,
the extremity thereof next to the cylinder door may be made so flexible, or
may be so arranged by means of gores, as to open out when the cylinder is
required to be loaded or unloaded, and to close up by means of the gores or
other appliances so as to form a water-tight end, when the cylinder door can
be closed and the operation carried on as before described.

page_text: Figures 7, 8, and 9, on Sheet II. of the Drawings show respectively a
longitudinal section, a transverse section, and a section of the equilibrium
valve to the arrangement of apparatus for carrying my Invention into practice,
in which the tank trucks A, A, are entirely closed, and antiseptic fluid and
water are respectively forced into them and the cylinder B to subject the
timber to the requisite pressure. For this purpose the tank trucks are provided
with a door D at one end, through which they are filled with timber, and
which is then closed in an air-tight manner; they are then placed inside the
cylinder B, where they are each connected by means of branch pipes E to a
pipe F.
This pipe communicates, firstly, with the tank G containing the
antiseptic fluid by means of a branch H; secondly, with an exhaust air pump
by means of a branch I; and thirdly, with a force pump for forcing in the
antiseptic fluid by means of a branch J. Each of these branches is provided
with a cock, as shewn. The cylinder B communicates directly with the water
tank K by means of a pipe L having a cock, and is furthermore in com-
munication with the before-mentioned air pump by means of the pipe M, and
with another pump for forcing in water by means of the pipe N. The tank
trucks A having been placed inside the cylinder B, and the end C closed in an
air-tight manner, the air is then exhausted simultaneously from the tank
trucks and cylinder by means of the before-mentioned air pump, the cocks in
the pipes I, J, L, and N, being at the time closed. A vacuum having thus
been formed, the cocks to the pipes H and L are opened, when the tank
trucks and cylinder become filled respectively with antiseptic fluid and water
by the pressure of the atmosphere. The cocks to the pipes H and L are then
closed, while those to the pipes J and N, communicating respectively with the
force pumps for antiseptic fluid and water, are opened, and such further
quantities of antiseptic fluid and water are now forced respectively into the
tanks and cylinder as to produce the requisite pressure both inside the tanks
and upon the outer surfaces of the same. T is the suction pipe to the pump
for antiseptic fluid, and U is the suction pipe to the water pump.
In order to cause the gradual increase of pressure to take place equally in
the tanks and cylinder, the pipes N and J are both connected to the equi-
librium valve shown at Figure 9; this valve consists of a cylinder O,
communicating at each end respectively with the pipes N and J, and having
two pistons P, R, connected together and capable of working backwards and
forwards in it. A fixed rim Q is provided to prevent the pistons P, R, from
working too far towards either of the pipes N or J.
It will be seen that if the pressure in the pipe J exceeds that in the pipe N,
or vice versa, the pistons will be moved in one direction or the other, so as to

page_text: uncover one of the apertures S, S', and the escape of the fluid through the
one or the other of these apertures will reduce the excess of pressure in the
one or the other of the pipes. When the timber in the tanks has been
sufficiently impregnated with the antiseptic fluid the latter is allowed to flow
back from the tanks A into the reservoir G through the pipes F and H, and
the water is at the same time allowed to flow off from the cylinder B into the
reservoir K through the pipe L, for which purpose air cocks V, V, V, com-
municating with the tanks A, A, A, and an air cock W, communicating with
the cylinder B, are provided. When the tanks and cylinder are empty, the
end C of the latter is opened, and the former are disconnected from the pipe F
and air cocks V, and the tanks are then removed from the cylinder.
Having now described the nature of my Invention, and the best means I am
acquainted with of performing the same, I wish it to be understood that I
do not claim the herein-before described arrangement of combined exhausting
and condensing air pump otherwise than in combination with and for the
purposes of the apparatus described, nor do I limit myself to the precise form
and arrangement of apparatus for carrying my Invention into practice, as
herein-before described with reference to the accompanying Drawing, as these
may obviously be variously modified without departing from the nature of my
Invention; but what I claim is,-
First, subjecting timber or other materials to the action of antiseptic or
other fluids under pressure, by enclosing the vessels containing the same,
immersed in the said fluid inside a strong receptacle, and there subjecting both
the fluid inside the vessels and the outer surfaces of the latter to one and the
same or nearly one and the same degree of pressure, substantially as herein-
before described with reference to the accompanying Drawings.
Second, the arrangement of apparatus for impregnating timber with anti-
septic or preservative fluids, in which the timber is placed inside tanks open at
the top, which are then placed inside a strong receptacle, and after there being
exhausted of air and filled with antiseptic fluid, while the outer receptacle is
filled with water or other fluid, are subjected both internally and externally to
one and the same pressure, by forcing air, steam, or other gases into the space
between the tops, or tops and sides of the tanks, and those of the outer
receptacle, substantially as herein-before described with reference to Figures 1.
to 4 on Sheet I. of the accompanying Drawings.
Third, the arrangement of apparatus for impregnating timber with antiseptic
or preservative fluids, in which the timber is placed inside tanks closed in a
water-tight manner, which are then placed inside a strong receptacle, and
after being exhausted of air and filled with antiseptic fluid, while the outer

page_text: receptacle is filled with water or other fluid, are subjected both internally and
externally to one and the same or nearly one and the same degree of pressure
by forcing simultaneously antiseptic fluid into the tanks, and water or other
fluid into the outer receptacle, substantially as herein-before described with
reference to Figures 7 to 9 on Sheet II. of the accompanying Drawings.
Fourth, constructing tanks, for containing the antiseptic fluid, of india-rubber,
substantially as herein-before described with reference to Figures 5 and 6 on
Sheet II. of the accompanying drawings.
Fifth, the arrangement of equilibrium valve, herein-before described, with
reference to Figure 9 on Sheet II. of the accompanying Drawings.
In witness whereof, I, the said Samuel Bagster Boulton, have hereunto
set my hand and seal, the Fifteenth day of September, One thousand
eight hundred and sixty-five.
S. B. BOULTON. (L.S.)