A NEW OB IMPROVED COMPOUND FOR THE MANUFACTURE OF CEMENTS OR ARTIFICIAL STONE, CAPABLE ALSO OF BEING USED AS AN ARTIFICAL FUEL."
Year: 1873

page_text: LETTERS PATENT to the Reverend Granville Hamilton Forbes, Rector
of Broughton, Northamptonshire, for the Invention of "A NEW OB
IMPROVED COMPOUND FOR THE MANUFACTURE OF CEMENTS OR ARTIFICIAL
STONE, CAPABLE ALSO OF BEING USED AS AN ARTIFICAL FUEL."
PROVISIONAL SPECIFICATION left by the Reverend Granville Hamilton
Forbes at the Office of the Commissioners of Patents, with his
Petition, on the 20th May 1873.
I, the Reverend GRANVILLE HAMILTON FORBES, Rector of Broughton,
Northamptonshire, do hereby declare the nature of the said Invention
for "A NEW OR IMPROVED COMPOUND FOR THE MANUFACTURE OF CEMENTS OR
ARTIFICIAL STONE, CAPABLE ALSO OF BEING USED AS AN ARTIFICIAL FUEL," to be
as follows:-

page_text: All the proportions above specified are by weight.
All the compounds specified above are capable of being used as an
artificial fuel with a small quantity coal or coke, or cinders, or wood.
I prefer the proportion of tar above specified, but I do not wish to tie
myself to use always this exact quantity, as it may be varied with the
requirements of the case.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the Reverend Granville Hamilton Forbes in the Great
Seal Patent Office on the 20th November 1873.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, the
Reverend GRANVILLE HAMILTON FORBES, Rector of Broughton, North-
amptonshire, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Twentieth day of May, in the year of
our Lord One thousand eight hundred and seventy-three, in the thirty-
sixth year of Her reign, did, for Herself, Her heirs and successors,
give and grant unto me, the said Granville Hamilton Forbes, Her
special licence that I, the said Granville Hamilton Forbes, my exe-
cutors, administrators, and assigns, or such others as the said Granville
Hamilton Forbes, 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 "A NEW OR IMPROVED COMPOUND FOR THE MANUFACTURE OF
CEMENTS OR ARTIFICIAL STONE, CAPABLE ALSO OF BEING USED AS AN ARTIFICIAL
FUEL," upon the condition (amongst others) that I, the said Granville
Hamilton Forbes, my executors 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,

page_text: NOW KNOW YE, that I, the said Granville Hamilton Forbes, 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 :-
My Invention has for its object an improved method of manufacturing
cement by intimately combining with the cement making materials
before calcination such combustible matter as will render the compound
capable of burning readily in a kiln or furnace, or stove or grate. The
advantage and utility of my Invention therefore is that I not only
improve the manufacture of cement by rendering the calcination of the
materials from which it is made more easy, expeditious, and complete,
but also that I produce a fuel suitable for domestic and other purposes
from the combustion of which an excellent cement or plaster may be
'made.
Having thus far briefly described and ascertained the nature of the
said Invention, and indicated in what manner the same is to be per-
formed or put in practice, in further compliance with the condition in
the said Letters Patent contained I will now further and particularly
describe and ascertain in what manner the same is to be performed or
carried out in practice.
In carrying my Invention into practice I proceed as follows :— -I
intimately mix the "foul" or refuse lime of gasworks (which is lime that
has been used for the purification of gas) with chalk or limestone, and
coal tar or tar produced by the distillation of coal and bitumen or
natural pitch. There are various means by which this mixture may be
effected. I use any convenient means, but the means that I prefer to
use is that of grinding the foul lime and the chalk or limestone in a
mortar mill, having previously dried these materials either by natural or
artificial heat. When the foul lime and the chalk or limestone have
been ground to a fine powder and thoroughly mixed together I add the
tar by degrees and work the whole well together in the mill. The
proportion of tar used will be about one-third (3) of the weight of the
other materials, but I do not tie myself to this proportion.
When the materials are thoroughly amalgamated I form the compound

page_text: machinery, or before taking the compound from the mill I compress it
by the action of the mill and cut it out of the pan in pieces. It is then
eady for burning either for the manufacture of cement or artificial
stone, or for fuel; it will burn freely, but a small quantity of coal or
ther fuel may be used with it. It may be burnt either in a grate or
tove, or in a kiln or furnace, but in any case care must be taken not to
verburn it. When sufficiently burnt it is reduced to a powder and is
hen ready for use as cement or for making artificial stone.
by the action of the mill and cut it out of the pan in pieces. It is then
ready for burning either for the manufacture of cement or artificial
stone, or for fuel; it will burn freely, but a small quantity of coal or
other fuel may be used with it. It may be burnt either in a grate or
stove, or in a kiln or furnace, but in any case care must be taken not to
overburn it. When sufficiently burnt it is reduced to a powder and is
then ready for use as cement or for making artificial stone.
The proportions of the foul limo and the chalk or limestone that I
use will vary considerably, according to circumstances, the quantity of
the foul lime being very uncertain.
I sometimes use two parts of foul lime to one part of chalk or lime-
stone, sometimes I use one part of foul lime to two parts of chalk or
limestone.
I reserve to myself the right to use (in every hundred parts of foul
lime and chalk or limestone) any per centage of foul lime above thirty-
three (33), but not less than this per centage.
Instead of the above method I sometimes use the following:-I grind
the foul lime and chalk or limestone in the mill with sufficient water to
form the compound into a thick paste. It is then dried either by
artificial heat or without it, and reground with the same proportion of
tar as before specified. I then proceed as before described.
Instead of chalk or limestone I sometimes use a combination of chalk
and limestone. All the above proportions are by weight.
Having thus particularly described and ascertained the nature and
object of my Invention, and in what manner the same is to be performed
or put in practice, I hereby declare that I claim the Invention of "A
New or Improved Compound for the Manufacture of Cements or
Artificial Stone, capable also of being used as an Artificial Fuel," in
which Invention particular and important points are,―
First. The use of the aforesaid foul lime in combination with chalk or
limestone (or chalk and limestone), and the above specified tar for the
purposes of manufacturing cement or artificial stone.

page_text: Secondly. The use of the combination above mentioned for the
purpose of making an artificial fuel capable of yielding after combustion
a residue valuable as a cement, or for making artificial stone.
In witness whereof, I, the said Granville Hamilton Forbes, have
hereunto set my hand and scal, this Eighteenth day of November,
in the year of our Lord One thousand eight hundred and seventy-
three.
Witness,
GRANVILLE HAMILTON FORBES. (L.s.)
FRANCES DAWKINS,
Broughton Rectory,
Northamptonshire.