AN IMPROVED COMBUSTIBLE COMPOUND DESIGNED TO BE USED AS FUEL OR FOR MAKING LINE
Year: 1873

page_text: LETTERS PATENT to Granville Hamilton Forbes, of Broughton
Rectory, in the County of Northampton, Clerk, for the Invention of
"AN IMPROVED COMBUSTIBLE COMPOUND DESIGNED TO BE USED AS FUEL OR FOR
MAKING LINE."
Scaled the 20th May 1873, and dated the 8th March 1878.
PROVISIONAL SPECIFICATION left by the said Granville Hamilton
Forbes at the Office of the Commissioners of Patents, with his
Petition, on the 8th March 1878.
I, GRANVILLE HAMILTON FORBES, of Broughton Rectory, in the
County of Northampton, Olerk, do hereby declare the nature of the said
Invention for "AN IMPROVED COMBUSTIBLE COMPOUND DESIGNED TO ER USED AS
FUEL OR FOR MAKING LIKE ";—
1
. My said Invention relates to a compound of chalk or limestone, and
tar, pitch, or bituminous matter with or without certain other ingredients
herein-after specified. The said compound is designed to serve as a
substitute for coal or other materials commonly used for fuel, or for
making lime,

page_text: The said improved compound is made as follows:-I take any desired
quantity of chalk or limestone, and thoroughly mix the same under
pressure with tar, pitch, or bituminous matter, in such a manner as to
make a compact substance capable of burning more or less readily,
according to the purpose for which it is to be used, and according to the
proportion of tar, pitch, or bitumen that is consequently used in the
manufacturo. I may also incorporate with the above ingredients any
desired proportion of wood or peat, or other vegetable substance in
fibre, or pulp, or dust, and a small quantity of naptha or other mineral
oil. The said compound may be moulded or otherwise formed into
blocks or pieces of any desired or convenient size and shape.
SPECIFICATION in pursuance of the conditions of the Letters Patent
filed by the said Granville Hamilton Forbes in the Great Seal
Patent Office on the 6th September 1878.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, GRANVILLE 1
HAMILTON FORBES, of Broughton Rectory, in the County of North-
ampton, Olerk, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Eighth day of March, in the year of
our Lord One thousand eight hundred and seventy-three, in the thirty- 2
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 executors,
administrators, and assigns, or such others as the said Granville
Hamilton Forbes, my executors, administrators, and assigns, should at 2
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 "AN IMPROVED COMBUSTIBLE COMPOUND DESIGNED TO BE USED AS FUEL OR FOR
MAKING LIKE," 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 §

page_text: 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 Granville Hamilton Forbes, do hereby
declare the nature of my said Invention, and in what manner the same
is to bo performed, to be particularly described and ascertained in and
by the following statement :-
According to the first part of my said Invention, I have for my object
the production of an article which is at once a good fuel and a source of
lime. I thus utilize the heat ordinarily. lost in the burning of tho
material from which lime is made. This object I effect by combining
with this material enough combustible matter to make a good fuel of
the compound, which may be used either as fuel or for the manufacturo
of lime.
5 In carrying out this part of my Invention I mix coal tar, or wood tar,
or peat tar, or mineral tar, or pitch, or other similar bituminous sub-
stance, or a combination of two or more of them with chalk or limestone,
or with any combination of the two, and in some cases with a small
quantity of naptha or mineral oil.
I have two methods of effecting this mixture of the chalk or limestone
with the tar, pitch, or other similar bituminous substances. My first
method is by the process of absorption. In this process I avail myself
of the absorbent nature of chalk to effect a combination of the tar or
pitch with the chalk, without reducing it to a powder. I break the
5 chalk into pieces of a convenient size by hand or machinery. I prefer
that no picco should be more than three or four inches in thickness, but
this is not absolutely essential. I then heat the chalk by means of an
oven, or in any other convenient manner, to such a degree that the
moisture is expelled from the chalk. It is then put hot into the tar or
› similar bituminous substance, and allowed to soak there until it has
absorbed a sufficient quantity of the tar or pitch for my purposo. If the
chalk be heated red hot, or nearly so, the effect of putting a sufficient
quantity of it into the tar will be to make the latter boil. This will
render the tar more liquid, and will facilitate the operation of absorption
3 very much. The chalk should be allowed to soak in the liquid until it
is sufficiently penetrated by the latter. I prefer to leave it in the tar

page_text: some little time after both are cool; but the length of time it should
remain will depend upon circumstances.
Sometimes the process of absorption will be more rapid than at other
times, owing to the varying absorbent power of different kinds of chalk.
The best fuel will of course be made by allowing the chalk to remain in ♪
the liquid until it has become thoroughly saturated by the latter. I do
not restrict myself however to this thorough saturation, though I greatly
prefer it. An inferior kind of fuel may be produced by removing the
chalk from the tar before it is thoroughly saturated, or even completely
penetrated by the tar. The hotter the chalk the more tar it will absorb 1
in a given time. If red hot when put into the tar it will absorb about
one-third of its own weight in a few hours. If completely immersed at
once there will be no danger of setting fire to the tar, and the result will
be thoroughly to saturate the chalk.
I sometimes use this method of absorption, or instead of it I may 1
sometimes use the following:-The heating of the chalk may be omitted,
and it may be placed in the tar after having been allowed to dry without
artificial heat. If sufficiently dry, it will in time absorb enough tar to
make an inferior fuel; and even when not completely dried the chalk
will absorb a certain amount of the tar.
2
Another method of effecting this process of absorption which I some-
times use is to place the chalk, when sufficiently dry, in boiling tar or
pitch, without previously heating the chalk, or after having heated it.
only enough to dry it sufficiently for my purpose.
Another method which I sometimes employ is to boil the chalk in the 2
tar or pitch. After boiling the chalk in the tar or pitch a sufficient time
I allow the chalk, to remain in the liquid until it has absorbed enough
tar or pitch for my purpose. I prefer to use the chalk thoroughly dry,
but I do not restrict myself to the use of it in that state.
I may use any of the above methods of absorption, according to the 3
quality of the fuel or lime which I wish to produce. When pitch is used
instead of tar for the process of absorption it must be rendered liquid by
heat.
I in some cases mix a small quantity of naphtha or mineral oil, or a
mixture of them, with the tar or pitch, from one part to four parts 3
nanhtha to sixtoon parts tor or nitch before placing the chalk in it

page_text: descripca in to various methods amoresaid. тле спесь от еще парциа
or mineral oil is to render the tar or pitch more liquid, and the resulting
compound more valuable. But if the chalk be put into this mixture
when red hot there will be danger of setting the mixture on fire; or if
the mixturo be heated too much some portion of the oil will be wasted.
It is therefore more desirable to use the naphtha or mineral oil in the
cool process than in the hot process; but I do not restrict myself only
to its use in the former case.
In those cases where limestone is found to be sufficiently porous for
the purpose I sometimes employ the process of absorption in dealing
with it, but, not having the absorbent power of chalk, limestone is not
so suitable for this process.
Instead of the above methods of absorption I may use the following
method:-I dry the chalk either by artificial heat or without it, and
then place it in an air-tight chamber, from which I afterwards exhaust
the air so as to produce a vacuum. I then admit the tar or pitch into
the chamber until the chalk is covered to a sufficient depth, and after-
wards readmit the air, by which means I bring about the absorption of
the tar or pitch by the chalk through the pressure of the atmosphere.
Sometimes, instead of the above method, I place the chalk and tar.or
pitch together in an air-tight chamber, and afterwards exhaust tho`air.
Having allowed sufficient time for the exhaustion of the air from the
chalk I readmit the air into the chamber. It is essential that the chalk
should be a sufficient depth below the surface of the tar or pitch to cover
the same when the process is complete.
The second method that I employ for mixing the chalk or limestone
with the tar or pitch is by reducing the chalk or limestone to a fine
powder, and thoroughly mixing it with about one-third of its weight of
tar or pitch. Instead of chalk or limestone I may use in some cases a
mixturo of chalk and limestone in varying proportions.
f
There are various means by which the chalk or limestone may be
reduced to powder, and mixed with the tar or pitch. I may. employ any
convenient means, but the means which I prefer to employ as being the
simplest and the best for this purpose is that of crushing and mixing the
3 chalk or limestone and the tar or pitch in a powerful mortar mill. The
chalk or limestone should be placed in the pan of the mill and crushed

page_text: to a powder before adding the tar or pitch. I sometimes use a drug mill
instead of a mortar mill. When the compound of chalk or limestone (or
chalk and limestone) and the tar or pitch has been thoroughly mixed
thic compound is pressed into balls or blocks of any convonient sizo either
by hand or machinery. Or before it is taken out of the pan of the mill it 5
may be compressed by the action of the mill, and then cut into pieces. .
But I prefer to use a powerful screw or lever press for the purpose.
After being. pressed the compound is ready for use as a fuel and for
making limo. In some cases I use a small quantity of naphtha or
mineral oil in addition to the tar or pitch in this process in the same 1
proportion as specified above, namely, from one part to four parts by
weight of naphtha or mineral oil, or a combination of them, to sixteen
parts of tar or pitch.
•
The seccond part of my Invention relates to a mixture of peat with
chalk or limestone, or any combination of the two, and the tar, pitch, 1
or similar bituminous substance before specified, with or without a
small quantity of naphtha or mineral oil for the purpose of producing
a good fuel, which is capable of yielding, after calcination, a material
which in some cases would be suitable for agricultural purposes as an
artificial limo'manure, and in other cases would be suitable for use as
lime for building purposes. The compound may be used either as a
fuel yielding a residue of more or less value, or simply for the
manufacture of the materials above specified. In carrying out this.
part of my Invention I proceed as follows:-I reduce the peat and
chalk or limestone (or any combination of the two) to a fine powder, and 2
to this I add about one-third its weight of tar or pitch. I thoroughly mix
the whole, and afterwards press the compound into blocks or balls of
any convenient size or shape. For effecting the intimate mixture of
these substances I prefer to use a powerful mortar mill or a drug mill.
I first grind the peat into a powder in the mill, I then add the chalk 8
or limestone (or a combination of the two) and grind it to a fine powder
with the peat. I then add the tar or pitch, pouring it into the pan of
the mill a little at a time. The whole of the materials are then
thoroughly amalgamated by the action of the mill. When sufficiently.
worked by the mill the compound is taken out and pressed either by 8
hand or machinery into blocks or balls of any convenient shape. Or it
may be compressed in the mill, as beforo described. But I prefer to
uso for the purpose a powerful screw or lover press....

page_text: In some cases instead of mixing the tar or pitch with the other
ingredients in the mill I use the following method:- Having intimately
mixed the chalk or limestone with the peat in the mill, as before
described, I add a sufficient quantity of water to work the powdor up
into a stiff paste in the mill. When thoroughly workòd the compound
is taken out and moulded into blocks or balls of any convenient sizo by
hand or by machinery; or it may be left in lumps as it comes from tho.
mill, but I prefer to mould it into shapes. It is afterwards driod, either
by artificial heat or without it, and soaked in the tar or pitch until it has
) absorbed sufficient tar or pitch for my purpose. I may uso in this case
any of those methods of absorption described in that portion of this
Specification which relates to the process of absorption. The proportion
of peat used in this compound will vary according to the purposes for
which the compound is designed. When the object is to make a fucl
capable of yielding a residue suitable for agricultural purposes I some-
times uso equal parts of peat and of chalk or limestone. Sometimes I
may use a smaller, sometimes a greater, proportion of pent. This will
depend upon the quality of the artificial lime manure that I wish to
produce, which will vary according to the requirements of the land or
O the crop for which it is intended to be used; in some cases a larger
proportion of the peat ashes being desirable in the manure, in others
a larger proportion of lime. I therefore reserve to myself the right to
use in the compound of peat and chalk or limestone from twenty-fivo
to seventy-five per cent. of peat, according to the requirements of tho
5 case.
When my object is to make a fuel capable of yielding a limo suitablo
for building purposes, after drying the blocks or lumps of the mixturo
of peat and chalk or limestone (or à combination of the two) with
water, I bake them in an oven, or by any other convenient means
O at a temperature of about 280 degrees for twenty-four hours. I then
grind them up again with the proportion of tar or pitch above specified
in a mortar mill or drug mill, and afterwards press the compound into
blocks or balls of any convenient size or shape.
Sometimes instead of grinding the blocks up with the tar after.
baking, as abovo described, I use the process of absorption, putting
them hot into the tar or pitch immediately they are taken from the
. oven, allowing them to remain in the tar or pitch until they have
absorbed sufficient of the liquid for my purpose. The proportion of

page_text: peat used in this instance may vary from twenty to forty per cent. of
deat by weight, to eighty or sixty per cent. of chalk or limestone (or any
combination of the two). For this purpose I use only that description of peat
which after being burnt yields in the ash the largest amount of carbonate
of lime and sulphate of lime.
In addition to the above specified ingredients. I may sometimes use
a small quantity of naphtha or mineral oil in the proportion specified
in the first part of this Specification.
'
Having thus fully described my said Invention, and the manner.
of performing the same, I wish it to be understood that I claim,—
First. The aforesaid combination of tar or pitch, or similar bitu-
minous substance, or any mixture of two or more of them with chalk
or limestone, or any mixture of chalk and limestone, for the purposes.
hercin specified.
'
1
Second. The use of naphtha or mineral oil in combination with chalk 1
or limestone, or chalk and limestone, for the purposes hercin specified..
Third. The combination of tar or pitch, or similar bituminous sub-
stance, with peat and chalk or limestone (or a combination of chalk and
limestone), for the purposes herein specified.
Fourth. The use of naphtha or mineral oil in combination with chalk 2
or limestone and peat, for the purposes herein specified.
Fifth. The combination of the substances herein specified by the
process of absorption, for the purposes described.
In witness whereof, I, the said Granville Hamilton Forbes, have
hereunto set-my hand and seal,' this Sixth day of September, 2
in the year of our Lord One thousand eight hundred and seventy-
three.
GRANVILLE HAMILTON FORBES.. (L.S.)
Witness,
JAMES EDWARDS,
8, Southampton Buildings,
London.