IMPROVEMENTS IN ARTI- FICIAL MATERIAL FOR PRODUCING GAS FOR ILLUMINATING PURPOSES
Year: 1866

page_text: LETTERS PATENT to John Hamilton, of Glasgow, in the County of Lanark,
North Britain, Merchant, for the Invention of "IMPROVEMENTS IN ARTI-
FICIAL MATERIAL FOR PRODUCING GAS FOR ILLUMINATING PURPOSES."
Sealed the 31st January 1867, and dated the 6th August 1866.
PROVISIONAL SPECIFICATION left by the said John Hamilton at the
Office of the Commissioners of Patents, with his Petition, on the
6th August 1866.
I, JOHN HAMILTON, of Glasgow, in the County of Lanark, North Britain,
Merchant, do hereby declare the nature of the said Invention of "IMPROVE-
MENTS IN ARTIFICIAL MATERIAL FOR PRODUCING GAS FOR ILLUMINATING PURPOSES,"
to be as follows, that is to say :-
This Invention, which has for its essential object the production of gas for
illuminating purposes, consists as follows:-A quantity of crude coal oil or
crude mineral residues or "bottoms" or other mineral oils, together with a
small proportion of naphthaline, are boiled, and whilst in a hot state are poured
over a quantity of sifted or pulverized coal known in the trade as "coal duff;"
coal, culm, or other pulverized coal may also be used. The mixture may be
made in a pug mill or other suitable mixing machine, and is then allowed to
stand for twenty-four hours or thereabouts, so as to permit a complete com-
bination of the gases of the coal with those of the oil and naphthaline. The

page_text: result is an artificial gas-producing material, and the following proportions are
found to produce good results :-One ton of coal, 20 to 30 gallons of oil, and
5 lbs. of naphthaline.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said John Hamilton in the Great Seal Patent Office on the 5th
February 1867.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JOHN
HAMILTON, of Glasgow, in the County of Lanark, North Britain, Merchant,
send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Sixth day of August, in the year of our Lord
One thousand eight hundred and sixty-six, in the thirtieth year of Her
reign, did, for Herself, Her heirs and successors, give and grant unto
me, the said John Hamilton, Her special license that I, the said John
Hamilton, my executors, administrators, and assigns, or such others as I, the
said John Hamilton, my executors, administrators, or 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 Invention for "IMPROVE-
MENTS IN ARTIFICIAL MATERIAL FOR PRODUCING GAS FOR ILLUMINATING PURPOSES,"
upon the condition (amongst others) that I, the said John Hamilton, by
an instrument in writing under my hand and seal, 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 John Hamilton, 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 state-
ment, that is to say :-
My said Invention, which has for its object the production of gas for
illuminating purposes, consists as follows:-A quantity of crude coal oil or
crude mineral residues or "bottoms? or other mineral oils, together with a
small proportion of naphthaline, are boiled, and whilst in a hot state are poured

page_text: over a quantity of sifted or pulverized coal known in the trade as "coal duff;"
coal, culm, or other pulverized coal may also be used. The mixture may be
made in a pug mill or other suitable mixing machine, and is then allowed to
stand for twenty-four hours or thereabouts, so as to permit of a complete
combination of the gases of the coal with those of the oil and naphthaline.
The result is an artificial gas-producing material.
And in order that my said Invention may be properly understood I shall
now proceed more particularly to set forth the system, mode, or manner in or
under which the same is or may be used or practically carried into effect in
manner following, that is to say :--The admixture of certain oleaginous fatty
or resinous substances with certain carbonaceous materials for the production
of illuminating gas is not novel, such an admixture or compound having been
previously known and failed was specified under Letters Patent granted to
Thomas Isaac Dimsdale, dated 23rd June 1854, and numbered 1889, for
mixing with carbonaceous matters fatty, oleaginous, or resinous substances
(or boghead coal) previous to the same being placed in the retort for the
production of gas. A somewhat similar Invention is specified under Letters
Patent granted to George Mackenzie, dated 15th March 1866, and
numbered 769, for "Improvements in Obtaining Illuminating Gas and Oil;"
whilst another Invention for the production of illuminating gas by the impreg-
nation of naturally or artificially dried peat with mineral oil previous to being
placed in the retort is specified under Letters Patent granted to William
Glassford Walker and Robert Frazer Smith, dated 12th July 1866, and
numbered 1827. I have made mention of these foregoing Inventions in order
that what is purely novel and original in my own present Invention may be
more accurately ascertained.
My present Invention, then, consists in admixing or commingling together
or combining heavy mineral oils and naphthaline in a heated state with finely
broken and screened or pulverized bituminous coal known in Northumberland
and some other districts as "duff," or with other screened or pulverized
bituminous coal, to form a.compound to be used in ordinary gas works for the
production of illuminating gas, being both economical and effectual, and
therefore beneficial, in its results.
In manufacturing or compounding the herein-before mentioned substances
for home and foreign consumption, and producing it in such state that it is
stable and convenient in nature and form for storage as well as transport by
land, and sea, I take of heated oil, naphthaline, and coal the following pro-
portions, but which proportions may be varied according to the degree of
bituminization of the coal :-To one ton (i.e., 20 cwt.) of screened or pulverized

page_text: bituminous coal I add forty gallons of the heavy oil of coal or heavy oil of shale
commercially known as "once run," which usually contains a large quantity
of paraffin, along with five pounds of naphthaline, which are specially adapted
for producing gas of a bigh illuminating power. From this mixture I have
obtained 15,000 cubic feet of good gas. In lieu, however, of using the heavy
oils of coal or shale, or in conjunction with one or both of these, I sometimes
employ any other heavy mineral oil or residue, such as that which remains in
the stills after the lighter oils are distilled over, and commercially known as
"glut" or "bottoms," consisting generally of mineral tar or pitch, and
sometimes having certain foreign substances combined therewith. The coal
is placed in a pug mill or in some other admixing machine, at which
time the heavy oil or oils herein-before referred to are poured into or upon
the screened or pulverized coal, the oils being previously heated. By this
mode of compounding the substances a thorough and complete combination of
them is effected; and the experiments which I have made show that it is
absolutely essential to heat the oil in order to produce a compound that is
stable, for if the materials are combined in the natural and cold state the oils
and coal separate to a considerable extent in a short time after they have
been admixed. The admixture of heated oils and coal is allowed to stand
for twenty-four hours or thereabouts, or it may be compressed or made
advantageously into bricks, balls, or other form, before being placed into
retorts. It is further to be understood that the use of heat in forming. the
admixture (besides producing a more stable compound) is to overcome the
viscous or glutinous nature of the heavy mineral oils. The use of oil in a
cold state to combine with carbonaceous substances I have found to be not
economical, whilst by using it in a hot state a larger quantity of gas is obtained
possessed of higher illuminating power, the heat having an influence in pre-
venting the condensation of the gas after being once formed. The heavy oil
of tar known in commerce as naphthaline may or may not be dispensed
with; when used it is admixed with and at the same time and by the same
means that the other parts of the admixture are combined, as herein previously
specified. By some persons the pungency of the smell of naphthaline and the
extreme purity of its gas may be considered advantageous. In distilling the
gases of the herein-before mentioned compound I prefer to use fire-clay
retorts and to effect the distillation at a bright red or white heat.
Having now described the nature of my said Invention, and the manner in
which the same is or may be used or practically carried into effect, I would
observe in conclusion that what I consider novel and original, and therefore-
claim as the Invention secured to me by the herein-before in part recited

page_text: Letters Patent is, the manufacture of a compound or admixture for the pro-
duction of illuminating gas in which the heavy mineral oils left after the
lighter portions are distilled off, with or without admixture with naphthaline,
are combined in a heated state with screened or pulverized bituminous coal,
as herein-before described, or any mere modification thereof.
In witness whereof, I, the said John Hamilton, have hereunto set my
hand and seal, this Fourth day of February, One thousand eight
hundred and sixty-seven.
Witness,
ST. JOHN VINCENT DAY, C.E.,
Patent Offices,
166, Buchanan Street,
Glasgow.
JOHN HAMILTON. (LS.)