A NEW AND IMPROVED MODE OF IMPREGNATING WOOD WITH OLEAGINOUS AND SALINE MATTERS
Year: 1868

page_text: LETTERS PATENT to Charles Henry Wells, of the City and State
of New York, United States of America, Gentleman, for the In-
vention of "A NEW AND IMPROVED MODE OF IMPREGNATING WOOD WITH
OLEAGINOUS AND SALINE MATTERS."-A communication from Charles
Augustus Seely of the same Place.
Sealed the 5th September 1868, and dated the 1st June 1868.
PROVISIONAL SPECIFICATION left by the said Charles Henry Wells
at the Office of the Commissioners of Patents, with his Petition, on
the 1st June 1868.
I, CHARLES HENRY WELLS, of the City and State of New York,
United States of America, Gentleman, do hereby declare the nature of
the said Invention for "A NEW AND IMPROVED MODE OF IMPREGNATING
WOOD WITH OLEAGINOUS AND SALINE MATTERS," a communication from
Charles Augustus Seely of the same Place, to be as follows:-
This Invention consists in immersing the wood in a bath of suitable
liquid, which bath is at a temperature above that of boiling water.

page_text: In this bath the wood is heated above the temperature of boiling water,
and the moisture and air contained in its pores are expanded and
dissipated. When the moisture and air are thus expelled the wood is
removed and immersed in a bath of impregnating liquid which is at a
temperature below that of boiling water. The pores of the wood as its
mass becomes cool are in a vacuous condition, and the impregnating
liquid readily fills them by reason of capillary attraction and the pressure
of the atmosphere.
In many cases the two baths may be composed of the same
substances, and in general it will be found advisable that they be
the same in those cases where the impregnating substance will bear a
temperature above that of boiling water. Whenever the impregnating
substance cannot be heated above the boiling point of water the first
or heating bath must be of such a nature that it will not be incompatible
chemically with the impregnating substance.
This Invention may also be successfully practised by the use of only
one immersing tank. When the wood has been immersed long enough
in the hot liquid this may be drawn off, and its place supplied by the
cold liquid, or the hot liquid may be allowed to cool spontaneously, or
may be cooled by artificial means.
The length of the time of immersion will depend much upon the
bulk of the wood, and especially upon its length, as the moisture and
air find escape only at its ends. As the steam and air escape they
bubble through the liquid, and the progress of the operation becomes
evident to the senses. The time of immersion in the cold bath depends
upon the same circumstances, but in practice the time of immersion
need not be uncertain as the progress of the operation may be ascertained
at any time by taking out a sample of the wood and inspecting it.
This process is especially useful for impregnating wood with crude
carbolic acid and with dead oil, and as these substances bear a tem-
perature above that of boiling water the two baths may be made of the
same material.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Charles Henry Wells in the Great Seal Patent
Office on the 24th November 1868.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, CHARLES
HENRY WELLS, of the City and State of New York, United States
of America, Gentleman, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the First day of June, in the year of our
Lord One thousand cight hundred and sixty-eight, in the thirty-first
year of Her reign, did, for Herself, Her heirs and successors, give
and grant unto me, the said Charles Henry Wells, Her special licence
that I, the said Charles Henry Wells, my executors, administrators, and
assigns, or such others as I, the said Charles Henry Wells, my execu-
tors, 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 "A NEW AND
IMPROVED MODE OF IMPREGNATING WOOD WITH OLEAGINOUS AND SALINE MATTERS,"
a communication from Charles Augustus Seely, of the same Place, upon
the condition (amongst others) that I, the said Charles Henry Wells,
my exccutors 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 next and immediately
after the date of the said Letters Patent.
NOW KNOW YE, that I, the said Charles Henry Wells, 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 :-
The nature of the said Invention consists in immersing the wood in
a bath of suitable liquid, which bath is at a temperature above that
of boiling water. In this bath the mass of the wood is heated above
the temperature of boiling water, and the moisture and air contained
in its pores are expanded and dissipated. When the moisture and air
are thus climinated the wood is removed and immersed in a bath of

page_text: water.
impregnating liquid, which is at a temperature below that of boiling
The pores of the wood as its mass becomes cool are in a
vacuous condition, and the impregnating liquid readily fills them by
reason of capillary action and the pressure of the atmosphere.
To enable others skilled in the art to use this Invention I will
proceed to describe it in detail.
Reference is made above to two baths, one being above the boiling
point of water, and the other below it. In many cases these baths may
be composed of the same substances, and in general it will be found
advisable that they be the same in those cases where the impregnating
substance will bear a temperature above that of boiling water. When-
ever the impregnating substance cannot be heated above the boiling
point of water the first or heating bath must be of such nature that it
will not be incompatible chemically with the impregnating substance.
This process is especially useful for impregnating wood with crude
carbolic acid and with dead oil. As these substances bear a temperature
above that of boiling water it is preferred to make the two baths of
the same material. On the one hand there is put into a suitable tank
of iron, wood, or other material sufficient crude carbolic acid to allow
the immersion of the quantity of wood to be treated. The liquid is
heated by means of an open fire applied beneath or by steam pipes
arranged in the tank, and when the temperature has reached 300° and
upwards it is in a fit condition for the immersion of the wood. The
wood if in small pieces or blocks may be tied in bundles or held
together by a crate to facilitate the handling; the wood is immersed and
the heat is maintained till the pores are freed from moisture and air.
The length of time of immersion which would be required will depend
much upon the bulk of the wood, and especially upon its length, as
the moisture and air find escape only at its ends. As the steam and
air escape they bubble through the liquid, and the progress of the
operation becomes evident to the senses. When it is judged that this
part of the process has been long enough continued the wood is lifted
out and immersed in a bath of crude carbolic acid which is below the
temperature of boiling water. The time of immersion in the cold bath
depends upon the same circumstances as the time of immersion in
the hot bath. The time of immersion desirable desirable in actual
practice need be no occasion however for uncertainty; the progress

page_text: of the operation may be ascertained at any time by taking out a sample
of the wood and inspecting it.
Another illustration of this process is in its operation in impregnating
wood with light petroleum oil. In this case the hot bath is a heavy
petroleum, which bears a temperature of 250° and upwards. The bath
is heated and the wood is immersed, as above described, and when the
water and air are discharged from its pores the wood is removed to the
cold bath of the impregnating light oil.
Another illustration is the case where wood is to be impregnated
with a weak saline solution, as, for example, of chloride of calcium.
In this case the hot bath is a strong saline solution, and the weak or
impregnating solution is the cold bath.
The essential feature of this Invention is the successive immersion*
of wood in a bath of liquid heated above the boiling point of water, and
then in the impregnating liquid at a temperature below the boiling
point of water.
Above is described the process as making use of two separate and
distinct tanks. But this Invention may also be successfully practised
by the use of only one immersion tank; thus, the tank being supplied
with the hot liquid the wood is immersed for a sufficient length of time,
when the hot liquid is drawn off, and its place is supplied by the cold
liquid.
In another method of procedure the wood is immersed in the hot
liquid, as last described, and when the heat has been maintained
sufficiently long to expel water and air the liquid may be allowed to
cool down spontaneously, or it may be cooled by artificial means; thus
the process is carried out by the use of one liquid and one containing
vessel.
With reference to the temperature of the hot bath it is to be observed
that it must not be too high and must not be too long continued.
The effect of too much heat is to injure the toughness of the wood or
to make it liable to crack. A temperature of about 300° at the
beginning of the immersion is not excessive, but as the process pro-
gresses the bath should be allowed to cool down gradually, till at the
time of the change of the liquids the mass of wood shall be at about
the temperature of 215°. The precise limits of temperature will vary
with different kinds of wood and "different liquids, but the observant

page_text: operator will be easily able to determine them in practice. The tem-
perature of the cold bath should be as low as possible consistently with
its fluidity. A liquid which becomes viscid by cooling cannot of course
be used at a very low temperature.
What is claimed and is desired to be secured by Letters Patent is,
the process of impregnating wood, substantially as described; and the
use in conjunction of the hot and the cold baths for the
described.
purpose
In witness whereof, I, the said Charles Henry Wells, have here-
unto set my hand and seal, this First day of October, in
the year of our Lord 1868.
CHARLES HENRY WELLS. (L.S.)
CHARLES HENRY WELLS. (L.S.)