AN IMPROVED PROCESS AND APPARATUS FOR PRESERVING WOOD.
Year: 1873

page_text: LETTERS PATENT to Charles Pierre Newton Weatherby, of the City
and State of New York, United States of America, now of No. 8,
Southampton Buildings, London, for the Invention of " AN IMPROVED
PROCESS AND APPARATUS FOR PRESERVING WOOD.'
Sealed the 2nd June 1874, and dated the 3rd December 1873.
PROVISIONAL SPECIFICATION left by the said Charles Pierre Newton
Weatherby at the Office of the Commissioners of Patents, with his
Petition, on the 3rd December 1873.
I, CHARLES PIERRE NEWTON WEATHERBY, of the City and State of
New York, United States of America, now of No. 8, Southampton
Buildings, London, do hereby declare the nature of the said Invention
for "AN IMPROVED PROCESS AND APPARATUS FOR PRESERVING WOOD," to be as
follows:-

page_text: a neutral sulphate when the pressure or excess of gas is removed. The
neutral sulphite is quickly converted by its union with another atom of
oxygen into the insoluble sulphate of lime or plaster of Paris (gypsum)
in the fibres of the wood, thus preserving the woody fibre against fire,
while the antiseptic properties of sulphurous acid protect the fibre of the
wood from dry rot.
In carrying my Invention into practise I proceed as follows:-The
wood should be first deprived of moisture; it is then placed in an air-tight
chamber capable of sustaining a pressure of 150 pounds to the square inch.
Over this chamber is another containing a solution of bisulphite of lime
(clear and free from undissolved lime), which is forced into the vessel by
pumps at a pressure of about 100 pounds per square inch; this pressure
is necessary, as the bisulphite is only soluble in an excess of gas, which
must be forced in under pressure. The solution should show 25° on
Baume's saccharometer. The lower chamber being filled with wood air
is then withdrawn from the said chamber, and a vacuum formed, and the
bisulphite is let down, and the wood saturated with it.
In addition to the above apparatus I use an ordinary brick furnace,
with door and hearth, as used in acid works for burning sulphur. It is
an advantage to have two of these furnaces. A pipe is connected with
the said furnace to convey the gas therefrom to a close vessel lined with
lead and half filled with water. The said pipe passes through the head
nearly to the bottom of this vessel, so that the hot gas passes through
the water and is cooled before getting to the pump valves, while the
sublimed sulphur is precipitated.
Two single action pumps are arranged in any convenient position, and
surrounded by water to cool and lubricate them. Suction pipes lead to
the receiving valves of the pumps, the same being provided with stop-
cocks. Force pipes lead from the port valves to convey the gas to a
lime tank and the bisulphite of lime receiver, which is placed above the
wood chamber. A close strong vessel of boiler plate lined with lead of a
capacity equal to double that of the said receiver is charged with lime
and water to a little over one-half its capacity; it has a man-hole, and a
rouser or stirrer driven by an engine; a' pipe conveys the gas to the
bottom of this vessel. There is also an open wooden vessel charged with
lime and water, called milk of lime. A pipe conveys any escaping gas

page_text: from the aforesaid boiler plate vessel to the bottom of this wooden vessel
through a descending pipe, where it is absorbed. A tank is provided for
furnishing pure gas to produce the pressure in the aforesaid receiver
after it is charged.
The sulphur furnace being lighted the pumps are started with the
cocks set to throw the gas into the aforesaid lime tank, where it is taken
up by the milk of lime, while the nitrogen of the atmospheric air passes
off by the escape pipe, the milk of lime in the lime tank being agitated
with the rouser. When the clear solution of bisulphite of lime marks
25° to 30° on Baume's gauge the mass in the said tank is allowed to
settle and clear itself, and the sulphur furnace is stopped. The clear
bisulphite is pumped into the receiver until the pressure gauge shows a
pressure of 100 pounds per square inch; the cock of the said receiver is
then closed, and the air in the aforesaid air-tight chamber is pumped
out until a vacuum is formed of 26 or 27 inches of mercury, the wood
in the said chamber being thus deprived of air. The cock between this
chamber and the receiver is now opened, and the said chamber is filled
with the bisulphite; the said cock is then closed, and the wood sub-
mitted to the action of the bisulphite until saturated. Another cock is
then opened, and the bisulphite pumped back into the receiver for the
next operation.
My improved process combines the following advantages, namely,
The material is antiseptic; it is perfectly soluble, so that the pores
of the wood can be filled, and the antiseptic becomes insoluble in the
wood after impregnation, and is therefore not liable to leak out.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Charles Pierre. Newton Weatherby in the Great
Seal Patent Office on the 3rd June 1874.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, CHARLES
O PIERRE NEWTON WEATHERBY, of the City and State of New York,
United States of America, now of No. 8, Southampton Buildings,
London, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by- Her
Letters Patent, bearing date the Third day of December, in the year of

page_text: our Lord One thousand eight hundred and seventy-three, in the thirty-
seventh year of Her reign, did, for Herself, Her heirs and successors,
give and grant unto me, the said Charles Pierre Newton Weatherby, Her
special licence that I, the said Charles Pierre Newton Weatherby, my
executors, administrators, and assigns, or such others as I, the said
Charles Pierre Newton Weatherby, 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 "AN IMPROVED PROCESS AND APPARATUS FOR PRESERVING
WOOD," upon the condition (amongst others) that I, the said Charles
Pierre Newton Weatherby, my executors or administrators, by an instru-
ment 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 next and immediately after the date of the said Letters
Patent.
NOW KNOW YE, that I, the said Charles Pierre Newton Weatherby,
do hereby declare the nature of my said Invention, and in what manner
the same is to be performed, to be particularly described and ascertained
in and by the following statement :-
-
According to this Invention I charge or saturate the pores of the
wood to be preserved with a cencentrated solution of bisulphite of lime
or baryta, the same being rendered soluble by excess of sulphurous acid
gas under pressure, or by refrigeration, and being made insoluble as a
neutral sulphate when the pressure or excess of gas is removed. Neutral
sulphite is quickly converted by its union with another atom of oxygen
into the insoluble sulphate of lime or plaster of Paris (gypsum) in the
fibres of the wood, thus preserving the woody fibre against fire, while the
antiseptic properties of sulphurous acid protect the fibres of the wood
from dry rot.
In carrying my Invention into practise I proceed as follows:-The
wood should be first deprived of moisture; it is then placed in an air-
tight chamber capable of sustaining a pressure of 150 lbs. to the square
inch. Over this chamber is another containing a solution of bisulphite
of lime (clear and free from undissolved lime), which is forced into the

page_text: vessel by pumps at a pressure of about 100 lbs. per square inch; this
pressure is necessary, as the bisulphite is only soluble in an excess of
gas, which must be forced in under pressure. The solution should show
25° on Baume's saccharometer. The lower chamber being filled with
wood air is then withdrawn from the lower chamber, and a vacuum
formed, and the bisulphite is let down, and the wood saturated with it.
In addition to the above apparatus I use an ordinary brick furnace,
with door and hearth, as used in acid works for burning sulphur; it is
an advantage to have two of these furnaces. A pipe is connected with
the said furnace to convey the gas therefrom to a close vessel lined with
lead, and half filled with water; the said pipe passes through the head
nearly to the bottom of this vessel, so that the hot gas passes through
the water, and is cooled before getting to the pump valves, while the
sublimed sulphur is precipitated.
Two single action pumps are arranged in any convenient position, and
surrounded by water to cool and lubricate them. Suction pipes lead to
the receiving valves of the pumps, the same being provided with stop-
cocks. Force pipes lead from the port valves to convey the gas to a
lime tank and the bisulphite of lime receiver, which is placed above the
wood chamber. A close strong vessel of boiler plate lined with lead and of
a capacity equal to double that of the said receiver is charged with lime
and water to a little over one-half its capacity. It has a man-hole, and
a rouser or stirrer driven by an engine. A pipe conveys the gas to the
bottom of this vessel. There is also an open wooden vessel charged with
lime and water (called milk of lime). A pipe conveys any escaping
gas from the aforesaid boiler plate vessel to the bottom of this wooden
vessel through a descending pipe, where it is absorbed. A tank is
provided for furnishing pure gas to produce the pressure in the aforesaid
receiver after it is charged.
The sulphur furnace being lighted the pumps are started with cocks
set to throw the gas into the aforesaid lime tank, where it is taken up by
the milk of lime, while the nitrogen of the atmospheric air passes off by
the escape pipe, the milk of lime in the lime tank being agitated with
the rouser. When the clear solution of bisulphite of lime marks 25° to
30° on Baume's gauge the mass in the said tank is allowed to settle and
clear itself, and the sulphur furnace is stopped. The clear bisulphite is
pumped into the receiver until the pressure gauge shows a pressure of

page_text: 100 lbs. per square inch; the cock of the said receiver is then closed,
and the air in the aforesaid air-tight chamber is pumped out until a
vacuum is formed of 26 or 27 inches of mercury, the wood in the said
chamber being thus deprived of air. The cock between this chamber
and the receiver is now opened, and the said chamber is filled with the
bisulphite; the said cock is then closed, and the wood submitted to the
action of the bisulphite until saturated. Another cock is then opened,
and the bisulphite pumped back into the receiver for the next operation.
My improved process combines the following advantages, namely,
the material used is antiseptic; it is perfectly soluble, so that the pores of
the wood can be filled, and the antiseptic becomes insoluble in the wood
after impregnation, and is therefore not liable to leach out.
Having thus fully described my said Invention, and the manner of
performing the same, I wish it understood that I claim,-
First. The process of preserving wood by means of sulphurous acid
combined with a base in the manner herein described.
Second. The apparatus for carrying the above process into effect, as
herein described.
In witness whereof, I, the said Charles Pierre Newton Weatherby,
have hereunto set my hand and seal, this Third day of June, in
the year of our Lord One thousand eight hundred and seventy-
four.
Witness,
WM. ROB. LAKE,
8, Southampton Buildings,
London.
C. P. N. WEATHERBY. (L.S.)