IMPROVEMENTS IN SEASONING WOOD
Year: 1872

page_text: LETTERS PATENT to John Henry Johnson, of 47, Lincoln's Inn
Fields, in the County of Middlesex, Gentleman, for the Invention
of "IMPROVEMENTS IN SEASONING WOOD."-A communication from
abroad by George Miles Wells, of Boston, Massachusetts, in the
United States of America.
PROVISIONAL SPECIFICATION left by the said John Henry Johnson
at the Office of the Commissioners of Patents, with his Petition,
on the 14th June 1872.
I, JOHN HENRY JOHNSON, of 47, Lincoln's Inn Fields, in the County
of Middlesex, Gentleman, do hereby declare the nature of the said
Invention for "IMPROVEMENTS IN SEASONING Wood," a communication to
me from abroad by George Miles Wells, of Boston, Massachusetts, in
the United States of America, to be as follows :—
This Invention consists in subjecting wood to the direct action of a
combined body of steam of a temperature sufficiently high to completely

page_text: coagulate the albumen contained in the wood for a sufficient length of
time only to allow the steam to fully permeate the wood, and then with-
drawing it from the steam before its action has perceptibly injured the
quality of the wood. When wood is thus immersed in confined steam
of a pressure due to the temperature above indicated it is quickly per-
meated by the heat, whereby the moisture it contains is converted into
steam, and thereby in great measure expelled, while the solid con-
stituents of its natural sap are retained solidified, and rendered highly
insoluble and impervious to water, the seasoning process is almost
instantly accomplished. When the steam of the pressure above stated:
has permeated with its heat every 'part of the wood it has performed all
the beneficial office in the seasoning process of which it is capable, and
a longer continuance of its action is injurious to the wood, but if when
the above desired effect has been fully produced the wood be immediately
withdrawn from the action of the confined steam so as to allow its
residual moisture, that is to say, the condensed steam contained in it
when so withdrawn, to escape in the atmosphere (which from inch pine
boards under favorable conditions it will do in ten to twenty days), not
only is the wood thereby thoroughly dried without receiving injury, but
certain novel and valuable changes are effected in it, namely, it is
rendered firmer, more solid, less brittle, and heavier, will absorb moisture
less readily, and consequently is less liable to be affected by atmospheric
changes or the action of heat or moisture than wood seasoned by any
process hitherto employed.
•
An apparatus suitable for carrying out the improved process, but
which forms no part of this Invention, consists of a tank or vessel for
receiving the wood to be treated, and a steam pipe for supplying the
requisite steam. One end of the tank should be provided with a hinged
door closing steam tight, and provided with suitable means for holding
it closed against the outward pressure of the steam.
A truck upon which the charge of wood may be piled, and a rail
track by which said truck may be run out from or into the tank, should
also be provided for convenient handling of the wood..
The pipe connecting the steam boiler with the tank should be pro-
vided with a throttle valve or cock, by which the communication can
be opened or closed at pleasure, and a blow-off pipe and valve should
be arranged for the discharge of the steam from the tank after a charge
"

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said John Henry Johnson in the Great Seal Patent.
Office on the 14th December 1872.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JOHN
HENRY JOHNSON, of 47, Lincoln's Inn Field, in the County of Mid-
dlesex, Gentleman, send greeting.
WHEREAS 'Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Fourteenth day of June, in the year
of our Lord One thousand eight hundred and seventy-two, in the
35th year of Her reign, did, for Herself, Her heirs and successors,
give and grant unto me, the said John Henry Johnson, Her special
license, that I, the said John Henry Johnson, my executors, adminis-
trators, and assigns, or such others as I, the said John Henry Johnson,
my executors, administrators, or 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 SEASONING WOOD," a communication to me from abroad
by George Miles Wells, of Boston, Massachusetts, in the United States.
of America, upon the condition (amongst others) that I, the said John
Henry Johnson, my executors or administrators, 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 imme-
diately after the date of the said Letters Patent.
NOW KNOW YE, that I, the said John Henry Johnson, do hereby
declare the nature of the said Invention, and in what manner the same

page_text: is to be performed, to be, particularly described and ascertained in and
by the following statement, that is to say :-
The said Invention consists in subjecting wood to the direct action of
a combined body of steam of a temperature sufficiently high to com-
pletely coagulate the albumen contained in the wood for a sufficient
length of time to allow the steam to fully permeate the wood, and then
withdrawing it from the steam before its action has perceptibly injured
the quality of the wood, it having been discovered that when wood is
thus immersed in confined steam of a pressure due to the temperature
above indicated, it being quickly permeated by the heat, whereby the
moisture it contains is converted into steam, and thereby in great
measure expelled, while the solid constituents of its natural sap are
retained solidified, and rendered highly insoluble and impervious to
water, the seasoning process is almost instantly accomplished, it also
having been discovered that when the steam of the pressure above stated
has permeated with its heat every part of the wood it has performed all
the beneficial office in the seasoning process of which it is capable, and
a longer continuance of its action is injurious to the wood, and that
if when the above desired effect has been fully produced the wood is
immediately withdrawn from the action of the confined steam and its
residual moisture, the same being the condensed steam contained in it
when so withdrawn, is allowed to escape in the atmosphere, which from
inch pine boards under favorable conditions it will do in ten to twenty.
days, not only is the wood thereby thoroughly dried without receiving
injury, but certain novel and valuable changes are effected in it, namely,
it is rendered firmer, more solid, less brittle, and heavier, will absorb
moisture less readily, and consequently is less liable to be affected by
atmospheric changes or the action of heat or moisture than wood
. seasoned by any process hitherto employed of which I have know-
ledge:
.
"
An apparatus suitable for carrying out the said improved process
consists of a tank or vessel for receiving the wood to be treated and a
The tank may be of
steam pipe for supplying the requisite steam.
cylindrical or other form, and should be of sufficient strength to resist
the stream pressure to which its contents are to be subjected. One end
should be provided with a hinged door closing steam tight; and provided
with suitable means for .holding it closed against the outward pressure
of the steam.

page_text: A truck upon which the charge of wood may be piled, and a rail
track by which said truck may be run out from or into the tank should
also be provided for convenient handling of the wood.
-
The pipe connecting the steam boiler with the tank should be pro-
vided with a throttle valve or cock by which the communication can
be opened or closed at pleasure, and a blow-off pipe and valve should
be arranged for the discharge of the steam from the tank after a
charge of wood has been subjected to its action for the required length
of time.
A small stop-cock should also be inserted in the bottom of the tank
for the discharge of the condensed steam and sap.
The operation of charging the tank with wood is simple and obvious.
When the charge of wood is properly introduced into the tank and the
tank closed the steam is admitted thereto until it is filled with steam
and the requisite pressure is obtained.
•
The wood is allowed to remain in the confined steam long enough
to produce the effect before described, and it is then withdrawn by an
obvious operation.
It has been démonstrated by trial and experiment that steam of a pres-
sure of thirty to forty pounds per square inch will in five to ten minutes
produce the desired effect as herein described upon pine boards one inch
thick, and therefore I advise the use of steam of about that pressure.
For thicker' wood or wood in larger masses the action of the steam must
be continued proportionally longer. But even upon pine wood three
inches thick the, action of the steam for fifteen minutes will usually
be found sufficient.
Harder wood will require proportionally longer time, the object
being to raise the temperature of the wood throughout to that of the
steam, and when it has fully permeated the wood that object is
accomplished.
The wood should then be withdrawn from the steam, and the moisture
which remains be permitted to escape in the atmosphere. The injurious
effect of the continued action of the steam after it has performed its
office as herein specified will not of course be immediately perceptible,
but if the action is prolonged for any considerable time, say, for an hour
or. more, and especially if steam of very high pressure, for example,

page_text: seventy pounds to the square inch or over be used the wood will be
thereby checked and discolored, and its quality injured..
The best result is therefore obtained when the wood is withdrawn
from the confined steam immediately after the temperature has been
raised to that of the steam.
E
The albumen of wood is not as thoroughly coagulated as is desirable
in this process by less than about 200° of heat (Fahrenheit). Steam
should therefore be used of a pressure involving at least this degree of
heat, and as a higher heat than, say, 260° or 280° is liable to injure the
wood, I would recommend the use in no case of steam with more than 1
fifty to sixty pounds pressure to the square inch, as before stated;
thirty to forty pounds pressure to the square inch is safer and more
convenient.
I am aware that wood has been subjected to the action of steam as
one step in the process of seasoning the same, but I am not aware that 1
the operation has ever been conducted as herein described so as to
produce the above described results...
I do not therefore claim broadly as my Invention the application of
the direct action of steam for the seasoning of wood..
Having now described and particularly ascertained the nature of the 2
said Invention, and the manner in which the same is or may be used or
carried into effect, I would observe in conclusion that what I consider
to be novel and original, and therefore claim as the Invention secured to
me by the herein-before in. part recited Letters Patent is, the process
which consists in subjecting wood to the action of confined steam under 2
a pressure, and for a time sufficient to produce the effects required, sub-
stantially as herein set forth, and then withdrawing it from the action
of the confined steam before such action perceptibly injures the quality.
of the wood.
In witness whereof, I, the said John Henry Johnson, have to this 3
my Specification set my hand and seal, the Thirteenth day of
Dreambos One thousand night hundred and sovente two