IMPROVEMENTS IN THE MANU- FACTURE OF PAPER, PASTEBOARD, CARDBOARD, AND MILLBOARD, WHEREBY THE SAME ARE ADAPTED FOR THE LAGGING OR CLEADING OF LOCOMOTIVE OR OTHER BOILERS, OR FOR OTHER PURPOSES."
Year: 1877

page_text: LETTERS PATENT to James Wotherspoon, of Glasgow, in the County of
Lanark, North Britain, for the Invention of "IMPROVEMENTS IN THE MANU-
FACTURE OF PAPER, PASTEBOARD, CARDBOARD, AND MILLBOARD, WHEREBY
THE SAME ARE ADAPTED FOR THE LAGGING OR CLEADING OF LOCOMOTIVE
OR OTHER BOILERS, OR FOR OTHER PURPOSES."
PROVISIONAL SPECIFICATION left by the said James Wotherspoon at the
Office of the Commissioners of Patents on the 25th October 1877.
JAMES WOTHERSPOON, of Glasgow, in the County of Lanark, North Britain.
'IMPROVEMENTS IN THE MANUFACTURE OF PAPER, PASTEBOARD, CARDBOARD, AND
MILLBOARD, WHEREBY THE SAME ARE ADAPTED FOR THE LAGGING OR CLEADING
OF LOCOMOTIVE OR OTHER BOILERS, OR FOR OTHER PURPOSES."
This Invention has for its object to render paper, pasteboard, cardboard, or mill-
board, made from wood or other paper pulp non-liable to injury by heat, and
whereby the same is fitted for being used for the lagging or cleading of locomotives
or other boilers or surfaces which are raised to high temperatures, and to be
also used as a substitute for the wood or felt lagging or cleading at present
employed.
The Invention consists in laying over or encasing paper, pasteboard, card-
board, or millboard, either on one or both sides, with a layer of asbestos or
amianthus.
The pulp from which the paper, pasteboard, cardboard, or millboard is made may
or may not have asbestos mixed with it, and it may also have a portion of the
tungstate or muriate of soda, or sulphate of alumina, or their equivalent mixed
therewith, the proportions of which vary with the quality of the pulp and asbestos
used.

page_text: In manufacturing paper, pasteboard, cardboard, or millboard, protected on one or
both sides by a layer of asbestos or amianthus, this may be effected in the paper-
making machine by causing the paper pulp and pulp of asbestos to flow thereinto
separately, so that layers of the two different kinds of pulp become deposited upon
one another..
In place, however, of depositing the layers upon one another in the wet state, as
herein-before described, dry layers of paper, pasteboard, cardboard, or millboard may
be laid over with adhesive matter, so as to cause the layers of asbestos to be firmly
attached thereto, when dry.
In applying paper, pasteboard, cardboard, or millboard for covering boilers or
other surfaces, according to this Invention, a layer of it is placed next to the boiler,
and the thickness of this may be afterwards increased to any desired extent by
placing thereon one or more layers of paper, pasteboard, cardboard, or millboard
having tungstate or muriate of soda, or sulphate of alumina, or their equivalent
mixed therewith; or the covering may be composed of a layer of asbestos
paper, or cloth with paper afterwards laid outside it, or it may be covered
with paper having tungstate or muriate of soda or sulphate of alumina nixed
therewith.
.
Besides being used for the purposes herein-before described, the paper, pasteboard,
cardboard, or millboard, encased and protected with asbestos, and with or without
admixture of tungstate or muriate of soda or sulphate of alumina, or their equiva-
lent, may be used for making the joints of pipes, cylender covers, steam chests, man-
hole doors, and other analagous joints of steam engines and boilers, gas and water-
works, and for other generally similar purposes.
When used for making joints which are in contact with liquids, steam, or other
vapours, the paper, pasteboard, cardboard, or millboard, prepared according to this
Invention, is laid over or soaked in "boiled oil" or a mixture of red lead
and oil.
For the purposes of this Invention, I find the pulp, commercially known as wood
pulp, to be advantageous.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said James Wotherspoon in the Great Seal Patent Office on the 20th April
1878.
JAMES WOTHERSPOON, of Glasgow, in the County of Lanark, North Britain.
"IMPROVEMENTS IN THE MANUFACTURE OF PAPER, PASTEBOARD, CARDBOARD, AND
MILLBOARD, WHEREBY THE SAME ARE ADAPTED FOR THE LAGGING OR CLEADING
OF LOCOMOTIVE OR OTHER BOILERS, OR FOR OTHER PURPOSES."
My said Invention has for its object to render paper, pasteboard, cardboard, or
millboard, made from wood or other paper pulp, non-liable to injury by heat, and
whereby the same is fitted for being used for the lagging or cleading of locomotive
or other boilers or surfaces, which are raised to high temperatures, and to be
also used as a substitute for the wood or felt lagging or cleading at present
employed.
My said Invention consists in laying over or encasing ordinary paper, paste-
board, cardboard, or millboard, either on one or both sides, with a layer of
asbestos.
The pulp from which the paper, pasteboard, cardboard, or millboard is made, may
or may not have asbestos mixed with it.
In manufacturing paper, pasteboard, cardboard, or millboard, protected on one or
both sides by a layer of asbestos or amianthus, this may be effected in the paper--
making machine by causing the paper pulp, or wood pulp, and pulp of asbestos to
flow thereinto separately, so that layers of the two different kinds of pulp become
deposited upon one another.
In place, however, of depositing the layers upon one another in the wet state, as
herein-before described, dry layers of paper, pasteboard, cardboard, or millboard may
be laid over with adhesive matter, such as paste, glue, or size, so as to cause the
layers of asbestos to be firmly attached thereto when dry.
In applying the paper, pasteboard, cardboard, or millboard, covered with asbestos,
for cleading or lagging boilers or other surfaces, according to this Invention, a layer
of it is placed next to the boiler, and the thickness of this may be afterwards
increased to any desired extent by placing thereon one or more layers of paper, paste-
board, cardboard, or millboard.
Besides being used for the purposes herein-before described, the paper, pasteboard,
cardboard, or millboard, encased and protected with asbestos, may be used for
making the joints of pipes, cylinder covers, steam chests, man-hole doors, and other
analogous joints of steam engines and boilers, for the pipes and analogous joints in
gas and waterworks, and for other generally similar purposes.
When used for making joints which are in contact with liquids, steam, or other
vapours, the paper, pasteboard, cardboard, or millboard, prepared according to
this Invention, is laid over or soaked in "boiled oil" or a mixture of red lead
and oil.
For the purposes of this Invention, I find the pulp, commercially known as wood
pulp, or pulp made from sawdust, to be advantageous.
Having now described and particularly ascertained the nature of my said
Invention, and the system, mode, or manner in or under which the same is or may
be used or practically 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, paper, pasteboard, card-

page_text: board, or millboard, whose exterior surface is rendered refractory or heat-resisting
by being coated with asbestos, as herein-before described.
In witness whereof, I, the said James Wotherspoon, have hereunto set my
hand and seal, this Nineteenth day of April, in the year of our Lord One
thousand eight hundred and seventy-eight.
JAMES WOTHERSPOON. (L.3.)