IMPROVEMENTS IN APPARATUS FOR PREPARING AND PRESERVING TIMBER
Year: 1859

page_text: LETTERS PATENT to Henry Potter Burt, of Charlotte Row, Mansion
House, in the City of London, for the Invention of "IMPROVEMENTS IN
APPARATUS FOR PREPARING AND PRESERVING TIMBER,"
Sealed the 22nd September 1859, and dated the 29th March 1859.
PROVISIONAL SPECIFICATION left by the said Henry Potter Burt at the
Office of the Commissioners of Patents, with his Petition, on the
29th March 1859.
I, HENRY POTTER BERT, of Charlotte Row, Mansion House, in the City of
London, do hereby declare the nature of the said Invention for "IMPROVEMENTS
IN APPARATUS FOR PREPARING AND PRESERVING TIMBER," to be as follows:―
The Invention relates to apparatus for impregnating railway sleepers and
other timber with creosote or other preservative liquids or solutions, which
apparatus may also be used for impregnating timber with liquids or solutions
for colouring the wood, or for rendering it incombustible. A. strong metallic
cylinder or vessel is employed with an air pump or other means of exhausting
the air, and a force pump or pumps for forcing in the liquid. The railway
sleepers or other pieces of timber to be prepared are packed on carriages,
which are pushed into the cylinder, and the end of the cylinder is then put on
and secured by screws or otherwise. The air is then exhausted by the air
pump. The air within the pores of the wood expands and drives out the
water and sap contained in it. The creosote or other liquid is then admitted
and pumped in until à considerable pressure per square inch is produced,
which forces the liquid into the wood. The liquid is then drawn off, and the
end of the cylinder is removed, and the carriages with the timber drawn out
and unpacked. I construct the carriages of angle iron, or other wrought-iron

page_text: bars braced in diagonal and other directions, and with draw bars cr hooks or
fastenings, by which several carriages may be connected together. Each
carriage has wheels, which run upon flat bars or plates supported by cross
bars, or by the cylinder itself. The carriage has two or more curved arms or
divided hoops within which the sleepers or other pieces of timber are packed,
and which are tied together at top by screws or otherwise. The carriages are
made heavy, and the plates or roads on which they run are rather wide, so
that if the timber should be floated by the liquid in the cylinder, the carriages
remain at the lower part and settle down on the road again, when the liquid is
withdrawn,or the carriagesmaybe made sufficientlyheavy to prevent the timber
from floating. At the bottom of the cylinder I place a vessel, the top of which
communicates with the interior of the cylinder by a valve or cock; another
valve or cock is placed at the bottom of this vessel. The upper valve or cock is
opened while the air is being exhausted from the cylinder. The sap and water
which exude from the timber run down and collect in the aforesaid vessel. The
upper valve or cock is then closed, and the creosote orother liquid is admitted
and forced into the cylinder as before mentioned. The lower valve or cock
is opened during or after the operation of impregnating the timber, and the sap
is drawn off. By opening and shutting the cocks or valves alternately during
the exhaustion or after the cylinder is exhausted, the aforesaid vessel may be
emptied several times,and the exhaustion may be continued until no more sap
or liquid collects in the vessel. I am thus enabled to judge of the progress of
the operation, and also to prevent the sap from becoming mixed with the
creosote or other liquid, and being partly forced back again into the timber.
The operation of impregnating the timber with creosote and manyother liquids
is facilitated by heating the liquid, and in order to maintain its temperature I
place one or more pipes along the bottom or other convenient part of the
cylinder, into which pipes I introduce steam or hot water or hot air.
Or a
jacket may be applied to a part or the whole of the cylinder for the same
purpose.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Henry Potter Burt in the Great Seal Patent Office on the
27th September 1859.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, HENRY
POTTER BURT, of Charlotte Row, Mansion House, in the City of London, send
greeting.

page_text: WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Twenty-ninth day of March, in the year of our Lord
One thousand eight hundred and fifty-nine, in the twenty-second year of Her
reign,did, for Herself. Her heirs and successors, give and grant unto me,
the said Henry Potter Burt, Her special licence that I, the said Henry
Potter Burt, my executors,administrators, and assigus, or such others as I, the
said Henry Potter Burt, myexecutors,administrators, and assigns, should'atany
time agree with, and no others, from time to time and at all times thereafter
during the term therain 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
APPARATUS FOR PREPARING AND PRESERVING TIMBER," upon the condition (amongst
others) that I,the said Henry Potter Burt, 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 performed, and cause the same
to be filed in the Great Seal Patent Office within six calendar months
uext and immediately after the date of the said Letters Patent.
NOW KNOW YE, that 1, the said Henry Potter Burt, 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 fol-
lowing statement thereof, reference being had to the accompanying Drawing,
and to the figures and letters marked thereon, that is to say:-
The Invention relates to apparatus for impregnating railway sleepers and
other timber with creosote or other preservative liquids or solutions, which
apparatus may also be used for impregnating timber with liquids or solu-
tions for colouring the wood, or for rendering it incombustible. A strong
metallic cylinder or vessel is employed, with an air pump or other means of
exhausting the air, and a force pump or pumps for forcing in the liquid. The
railway sleepers or other pieces of timber to be prepared, are packed on
carriages which are pushed into the cylinder, aud the end of the cylinder is
then put on and secured by screws or otherwise; the air is then exhausted by
the air pump. The air within the pores of the wood expands and drives out
the water and sap contained in it. The creosote or other liquid is then
admitted, and pumped in until a considerable pressure per square inch is pro.
duced, which forces the liquid into the wood; the liquid is then drawn off,and
the end of the cylinder is removed, and the carriages, with the timber drawn
out and unpacked. I construct the carriages of angle iron or other wrought-
iron bars braced in diagonal and other directions, and with drawbars or hooks

page_text: or fastenings, by which several carriages may be connected together. Each
carriage has wheels, which run upon flat bars or plates supported by cross bars
or by the cylinder itself. The carriage has two or more curved arms or
divided hoops, within which the sleepers or other pieces of timber are packed,
and which are tied together at top by screws or otherwise. The carriages are
made heavy, and the plates or roads on which they run are rather wide, so that
if the timber should be floated by the liquid in the cylinder, the carriages
remain at the lower part and settle down on the road again when the liquid
is withdrawn; or the carriages may be made sufficiently heavy to prevent the
timber from floating. At the bottom of the cylinder I place a vessel, the top
of which communicates with the interior of the cylinder by a valve or cock.
Another valve or cock is placed at the bottom of this vessel. The upper valve
or cock is opened while the air is being exhausted from the cylinder. The sap
and water which exude from the timber run down and collect in the aforesaid
vessel. The upper valve or cock is then closed, and the creosote or other liquid
is admitted, and forced into the cylinder as before mentioned. The lower
valve or cock is opened during or after the operation of impregnating the
timber, and the sap is drawn off. By opening and shutting the cocks or valves
alternately during the exhaustion, or after the cylinder is exhausted, the afore-
said vessel maybe emptied several times,and the exhaustion maybe continued
until no more sap or liquid collects in the vessel. I am thus enabled to judge
of the progress of the operation, and also to prevent the sap from becoming
mixed with the creosote or other liquid, and being partly forced back again
into the timber. The operation of impregnating the timber with creosote and
manyother liquids is facilitated by heating the liquid, and in order to maintain
its temperature I place one or more pipes along the bottom or other convenient
part of the cylinder, into which pipes I introduce steam or hot water or hot
air. Or a jacket may be applied to a part or the whole of the cylinder for the
same purpose.
Figure 1 of the accompanying Drawing is a transverse section of an appa-
ratus constructed according to my Invention; Figure 2 is a longitudinalsection
of a portion of the same. The same letters refer to similar parts in each
Figure. A is the cylinder of wrought iron or other strong material, the end
of which is closed by a cover B secured by screws C, C; D, D, are cross bars
carrying the rails or trams E, E,on which run the wheels F,F, of the carriages;
Figure 3 is a plan of one of the carriages, it is constructed with two side
bars a, a, of angle iron, and two end bars 6, 6, also of angle iron, and having
their ends bent up and rivetted to the side bars. One or more cross bars c,also
of angle iron,is or are rivetted to the side bars a,a, thus dividing the frame into

page_text: two or more rectangular compartments,in cachof which is a crossformed of two
diagonal flat barsd,d, rivetted to thesidebars a,a. Along flat bar e, with a hook
oreyeateach end, passes under the frame and is rivetted to the bars b,b,c,d,d.
This bar serves for connecting the carriages together for drawing them in and
out; a strong light frame is thus produced; ff.f.f, are four flat bars, bent
into the form shown in the Drawing, and rivetted to the side plates a, a. The
wheels F, F, F, F, are mounted on pins or short axles g. passed through the
bars fand side bars a, and secured by keys or linch pins. Two short angle
pieces h, h, are rivetted to each barf; G, G, are curved arms, jointed or
hinged on pins passing through the pieces h, h, and connected at top by a
hooked link H. The railway sleepers or other pieces of timber are packed
on the carriage between the arms G, G, which are drawn together and con-
nected by the link H, and the carriage is pushed into the cylinder A. The
different carriages are connected by short chains attached to the bars e. The
rails or trams E have flat surfaces of considerable width, so that if the timber
and the carriage are floated by the liquid, they settle down again into their
proper positions on the withdrawal of the liquid. If the cylinder is smooth in
the interior it may serve as the guide for the wheels; but if made with lap
joints and rivetted in the usual manner, I prefer to bend up the side of the
bar so as to follow the general form of the cylinder and to form a straight
guide for the whole length of the cylinder. These bars or rails may be made
of wrought iron or cast iron. They are strengthened by ribs on their under
sides, which terminate at the cross bars D, to which the bars or trams E aro
bolted or rivetted. The lower plates of the cylinder A are lapped outside the
side plates,as shewn at m, m, and the tee iron cross bars 1) are fitted under
the edges of the side plates, being angled into their places. The rails E being
then laid upon them and rivetted or bolted to them the whole is secured in its
place without the necessity of boring holes in the cylinder for the insertion of
bolts or other fixings. In lieu of making the rails E with ribs on their
undersides, they may be simple iron plates fixed ou longitudinal timbers, and
having their sides bent up like the rails E. The longitudinal timbers may be
kept apart by struts, and bolted or otherwise secured inthecylinder. Creosote
and most other liquids penetrate the wood quicker when heated, and the
preserving liquid is sometimes heated beforeitis introduced into the cylinderA.
As however it has frequently to remain a considerable time in the cylinder À,it
gradually loses heat, particularly in cold weather. I maintain or raise the tem-
perature of the liquid by means of one or more pipesIplaced withinthe cylinder,
and with its or their ends passing through the bottom or end of the cylinder,
and traversed by a current of steam or hot water or hot air, supplied from any

page_text: convenient source.
K is a close vessel, placed below the cylinder A and
communicating with it by one or more pipes and cocks L; M, is a cock
at the bottom of the vessel K; and N is another cock at the top of the
vessel. When a charge of timber has been placed in the cylinder A, and the
cover B has been secured, the air is exhausted from the cylinder by air
pumps or otherwise in the usual manner. The cocks M and N are closed,
and the cock L, is opened. As the exhaustion proceeds the air in the pores of
the wood expands and drives out the sap and water contained in the wood.
This liquid flows down and passes by the pipe L into the vessel K. If this
pipe is sufficiently large, the air can ascend in it while the sap descends;
or if two pipes are employed, the air may ascend in oue pipe while the
sap descends in the other. When the sap has filled or partially filled
the vessel K, the cock L is closed, and if there is a second similar pipe
that is also closed, and the cocks M, N, are opened. The sap then flows
out at the cock M, while air enters at N. When the vessel K is empty, the
cocks M, N, are closed, and L is again opened. If any sap remains in the
cylinder A, it now runs into the vessel K, which is again discharged in a
similar manner as often as may be required. When the cylinder A has
thus been emptied of sap, the exhaustion is still maintained, and after a time
the vessel K is again discharged, and so on, until sap ceases to accumulate
in the vessel K, or nearly so. The cock Lis then closed, and the creosote or
other preservative liquid is allowed to enter the cylinder A, and cover the
timber. The liquid is then forced in by pumps, in the usual manner, until a
sufficient pressure is obtained for forcing it into the pores of the timber.
After the timber is thus saturated and impregnated with the creosote or other
liquid, the liquid is run out into its cistern, and the cover of the cylinder is
removed, and the timber withdrawn. By the application of the vessel K, as
herein-before described, I am enabled to ascertain when the sap has been
withdrawn from the wood, and I also prevent the sap from mixing with and
contaminating the preservative liquid, and being forced back again into the
pores of the wood. By weighing the timber before and after the operation,
and. measuring or weighing the sap which is drawn off, I am enabled to
ascertain the proportion of sap and the quantity of creosote or preservative
liquid absorbed by the timber. Solutions for coloring or staining the wood,
and odoriferous solutions for scenting the wood,and solutions for tendering it
uninflammable, may be applied in a similar manner without being con-
taminated or diluted by mixing with the sap or water expelled fromthe wood.
When two solutions are to be applied in succession the sap is removed, and
the first solution is applied as herein-before described. I his solution is then

page_text: drawn off, and the air is again exhausted; a quantity of the first solution is
thus expelled from the wood, and is drawn off by means of the vessel K.
When this solution ceases to run into the vessel K,that vessel is shut off from
the cylinder A,and the second liquid is introduced into the cylinder, and forced
into the timber. In some cases I saturate the timber with creosote or other
liquid, as herein-before described, and, after drawing off the liquid, I again
exhaust the air, by which means a quantity of the liquid is expelled from the
wood, and I remove it by means of the vessel K. The interior of the pores
of the wood is thus wetted with the liquid, without consuming so large a
quantity of liquid as if the pores were left full of it.
Having now described the nature of the said Invention, and in what
mauner the same is to be performed, I wish it to be understood that what I
claim is,
First, constructing the carriages of apparatus for preparing and preserving
timber of wrought-iron bars and angle iron combined and connected as herein-
before described; also, the particular arrangement and construction of the
tramway in the cylinder for supporting and guiding such carriages,as herein--
before described in reference to the accompanying Drawing.
Second, the application in apparatus for preparing and preserving timber,
of the nature of that herein-before described, of steam pipes, or hot water
pipes, or hot air pipes for heating the liquid during the operation, as herein-
before described.
Third, the application in apparatus for preparing and preserving timber, of
the nature of that herein-before described, of the vessel for discharging the
sap or other liquid, as heroin-before described.
In witness whereof, I, the said Henry Potter Burt, have hereunto set
my hand and seal, this Twenty-fourth day of September, in the year
of our Lord One thousand eight hundred and fifty-nine.