IMPROVEMENTS IN THE MANUFACTURE OF GAS
Year: 1860

page_text: LETTERS PATENT to John Leslie, of Conduit Street, Hanover Square, in
the County of Middlesex, Esquire, for the Invention of "IMPROVEMENTS
IN THE MANUFACTURE OF GAS."
Scaled the 28th December 1860, and dated the 7th July 1860.
PROVISIONAL SPECIFICATION left by the said John Leslie at the
Office of the Commissioners of Patents, with his Petition, on the.
7th July 1860.
I, JOHN LESLIE, of Conduit Street, Hanover Square, in the County of
Middlesex, Esquire, do hereby declare the nature of the Invention for
"IMPROVEMENTS IN THE MANUFACTURE OF GAS," to be as follows:-
This Invention has for its object improvements in the manufacture of gas.
For these purposes, in distilling coal or other substance, the gas, in place of
being conducted off from the upper part of the retort, and thence into the
hydraulic main, is caused to descend from the retort at the lower part thereof
into a chamber, and thence the gas is conducted off by a pipe at the upper
part of the chamber to purifiers. Several retorts may be connected with the
same chamber, in which case they each have a slide or other valve to. shut the
entrance into the chamber. And in purifying gas, a solution of a salt of
copper, preferring the sulphate, is employed to saturate wood shavings or other
porous material, through and amongst which the gas is caused to pass. The

page_text: purifying matters thus employed are from time to time subjected to the passage
of atmospheric air amongst them to reprepare them for the further purification
of gas therewith.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said John Leslie in the Great Seal Patent Office on the 5th
January 1861.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JOHN
LESLIE, of Conduit Street, Hanover Square, in the County of Middlesex,
Esquire, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Seventh day of July, in the year of our Lord
One thousand eight hundred and sixty, in the twenty-fourth year of Her
reign, did, for Herself, Her heirs and successors, give and grant unto me, the
said John Leslie, Her special licence that I, the said John Leslie, my
executors, administrators, and assigns, or such others as I, the said John
Leslie, 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 "IMPROVEMENTS IN THE
MANUFACTURE OF GAS," upon the condition (amongst others) that I, the said
John Leslie, 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.
NOW KNOW YE, that I, the said John Leslie, do hereby declare the
nature of the 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 thereof, that is to say:―
This Invention has for its object improvements in the manufacture of gas.
For these purposes, in distilling coal or other substance, the gas, in place of
being conducted off from the upper part of the retort, and thence into the
hydraulic main, is caused to descend from the retort at the lower part thereof
into a chamber, and thence the gas is conducted off by a pipe at the upper

page_text: part of the chamber to purifiers. The chamber for this purpose may be of
any convenient form, having an outlet at the bottom, and a syphon pipe to run
off the fluid condensed therein, also a pipe at the top to convey the gas to the
purifiers. The gas pipe at the bottom and near the front end of the retort
descends into the chamber to about one-third of the depth of the chamber, which
I prefer to be about three feet deep and one foot diameter. Several retorts
may be connected with the same chamber, the chamber being suitably
enlarged. In all cases each retort should have a slide or other valve to shut
the entrance into the chamber; and in purifying gas, a solution of a salt of
copper, preferring the sulphate, is employed to saturate wood shavings or other
porous material, through and amongst which the gas is caused to pass. The
purifying matters thus employed are from time to time subjected to the
passage of atmospheric air amongst them to reprepare them for the further
purification of gas therewith.
The solution preferred is at the rate of one pound of the salt of copper to
two quarts of water, but the same may be varied. This solution is used to
saturate porous matters, such as wood shavings, sawdust, wood, charcoal, or
other porous material. These saturated matters are by preference placed in
a tower or chamber six or more feet in height and about two feet diameter for
one retort. The gas is admitted at the bottom, and conveyed off at the top.
These purifying matters are from time to time to have streams of atmospheric
air passed through them in order to restore them for being again and again
used.
In witness whereof, I, the said John Leslie, have hereunto set my
hand and seal, this Fourth day of January, in the year of our Lord
One thousand eight hundred and sixty-one.