IMPROVE- MENTS IN DRYING TIMBER
Year: 1874

page_text: LETTERS PATENT to Alexander M'Neile, of John Street, Pentonville, in
the County of Middlesex, Engineer, for the Invention of "IMPROVE-
MENTS IN DRYING TIMBER,"
Sealed the 11th September 1874, and dated the 17th July 1874.
PROVISIONAL SPECIFICATION left by the said Alexander McNeile at
the Office of the Commissioners of Patents, with his Petition, on
the 17th July 1874.
I, ALEXANDER MCNEILE, of John Street, Pentonville, in the County
of Middlesex, Engineer, do hereby declare the nature of the said Inven-
tion for "IMPROVEMENTS IN DRYING TIMBER," to be as follows:-
-
The object of the present Invention is to dissolve out and remove the
sap from timber, and to dry or season the latter ready for use. To this end
I place the timber in a close chamber, to which I admit carbonic acid
gas, which is made to combine with the aqueous vapor given off by
the evaporation of water. A convenient mode of doing this is to
place the water in shallow vessels, which are placed in any convenient
pårt of the close chamber where the water may be exposed to such a
[Price 8d.]

page_text: degree of heat as will slowly vaporize it. It is important that the vessels
containing the water should be so placed that the hot gases shall
come in contact with the aqueous vapour before reaching the timber to
be dried.
In carrying out my Invention I prefer to obtain the carbonic acid gas
from the combustion of fuel or carbonaceous matter, to which may be
added common chalk or limestone for the purpose of increasing the
quantity of carbonic acid.
The heated vapours from the combustion of the fuel and other matters
are carried forward from the fire-place, and brought in contact with the
shallow vessels (containing water) in the close chamber.
The heat will cause the water to evaporate slowly, and the dry carbonic
acid gas will combine with the aqueous vapour thus produced, and will
act upon and dissolve the sap in the wood, which will thereby become
dry and seasoned.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Alexander M'Neile in the Great Seal Patent
Office on the 16th January 1875.
:
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, ALEXANDER
MCNEILE, of John Street, Pentonville, in the County of Middlesex,
Engineer, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Seventeenth day of July, in the year
of our Lord One thousand eight hundred and seventy-four, in the
thirty-eighth year of Her reigu, did, for Herself, Her heirs and suc-
cessors, give and grant unto me, the said Alexander McNeile, Her
special licence that I, the said Alexander M'Neile, my executors,
administrators, and assigns, or such others as I, the said 'Alexander
M'Neile, my executors, administrators, and assigns, should at any time.
agree with, and no others, from time to time and at all times there-
after 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 In-
vention for "IMPROVEMENTS IN DRYING TIMBER," upon the condition
.

page_text: (amongst others) that I, the said Alexander M'Neile, my executors, or ad-
ministrators, 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
caused 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 Alexander M'Neile, do hereby declare
the nature of my said Invention, and in what manner the same is to be per-
formed, to be particularly described and ascertained in and by
the following statement, reference being had to the Drawing hereunto
annexed and to the letters and figures marked thereon (that is to
say):-
The object of the present Invention is to dissolve out the sap from
timber, and, to dry or season it in a much more expeditious manner than
by air drying without deteriorating the quality of the timber. To this end
I place the timber in a close chamber, and submit it to the action of a
heated mixed atmosphere of carbonic acid gas and aqueous vapour.
In carrying out my Invention I prefer to obtain the carbonic acid gas
from the combustion in the drying chamber of coal or other fuel, to
which may be added common chalk or limestone for the purpose of increas-
ing the yield of the carbonic acid, and this gas in a heated state I cause
to play on and over a shallow vessel or vessels containing water, in order
that it may vaporize the same and produce a damp atmosphere within the
drying chamber.
In the accompanying Drawing I have shewn an arrangement of drying
stove which I have found to answer the requirements of my drying
process, Fig. being a front elevation of the stove; Fig. 2, a sectional
plan of the same taken in the line 1, 2, of Fig. 1; and Fig. 3, a
vertical transverse section of the stove. In this example the stove,
which is made of brickwork, is divided by a central wall into two drying
chambers A, A', which are intended to be used independently of each
other, and will be fitted in a precisely similar manuer to receive timber
B, B, which is supported upon iron girders C having their bearings in
the brickwork. In the lower part of each drying chamber is a fire-
place D, the flue of which extends to about the middle of the chamber
in order to allow of the gases of combustion as they escape through a

page_text: contracted opening in the end thereof to play on to the bottom of a
shallow vessel E placed between the crown of the fire-place D and the
iron girders C. This vessel E is supported by transverse bars F having
their bearings in the side walls of the chamber. Water is supplied to
the vessels E of the drying chambers by any convenient arrangement of
pipes, as for example that shewn at G, G, Figures 1 and 3, such pipes
being connected with an elevated tank or head, which will offer a
constant supply of water to the vessels to compensate for the evaporation
that takes place therein. Each vessel E is provided with an overflow
and draw-off pipe H, I and a branch pipe may be conveniently led down
to the fire-places D, as shewn at K, for throwing a jet on to the fire
when required. The drying chambers are constructed with suitable
doorways for facilitating access thereto for the purpose of stacking the
timber thereon, and removing it when dried. The chambers I furnish
at their opposite sides with chimnies provided with dampers, which will
enable me to regulate the draft and equalize the circulation of the moist
carbonic acid gas throughout the stack of timber. It will now be
understood that when a fire is lighted in the fire-place D the heat thereby
generated will cause the water to vaporize slowly, and the dry carbonic
acid gas flowing from the fire-place will combine with the aqueous
vapour, and passing upwards through the stack of timber will permeate
the wood and act upon and dissolve the sap contained therein. At the
same time it will drive out the natural moisture of the wood, and dry
and season it.
I would remark that in no case will the temperature required to dry
and season timber be high, and care must be taken that the temperature
of the atmosphere surrounding the stack shall never approach to a
charring heat.
I may state as an example that in treating English hard wood planks
three inches in thickness may be dried by exposing them to a tempera-
ture not exceeding one hundred and twenty degrees, the same being
maintained for from six to eight weeks. It will however be understood
that the time required for drying the timber will vary according to the
nature of the material under treatment. The timber when removed from
the kiln should be stored for a few days before being used.
It should also be remarked that when treating mahogany and other
woods which are valued for their colour the use of coal in the fire-place

page_text: is objectionable, as the sulphurous acid generated from the combustion
of the coal has a bleaching effect upon the wood.
Having now set forth the nature of my Invention of "Improvements
in Drying Timber," and explained the manner of carrying the same into
effect, I would remark that it is not new to dry wood in an atmosphere of
steam, neither is it in my opinion beneficial to submit wood to the action of
dry carbonic acid gas; what I claim as my Invention is, submitting tim-
ber to a heated atmosphere composed of aqueous vapour and carbonic acid
gas, the same being obtained and applied substantially in the manner above
described.
In witness what I ihn anil Alamanda MENTAL
ALEX. MCNEILE. (1.s.)