IMPROVEMENTS IN THE COMBUSTION OF GAS FOR THE PURPOSE OF LIGHT
Year: 1847

page_text: TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JOHN
LESLIE, of Conduct Street, Hanover Square, in the County of Middlesex,
Tailor to Her Majesty, send greeting.
WHEREAS Her present most Excellent Majesty Queen Victoria, by Her
Royal Letters Patent under the Great Seal of the United Kingdom of Great
Britian and Ireland, bearing date at Westminster, the Twenty-second day of
March, One thousand eight hundred and forty-seven, in the tenth year of Her
reign, did, for Herself, Her heirs and successors, give and grant unto me,
the said John Leslie, my exors, adññors, and assigns, Her especial licence,
full power, sole privilege and authority, that I, the said John Leslie, my exors,
adñiors, and assigns, or such others as I, the said John Leslie, my exors,
adors, or assigns, should at any time agree with, and no others, from time
to time and at all times during the term of years therein expressed, should
and lawfully might make, use, exercise, and vend, within England, Wales,
and the Town of Berwick-upon-Tweed, my Invention of "IMPROVEMENTS IN
THE COMBUSTION OF GAS FOR THE PURPOSE OF LIGHT;" in which said Letters Patent
is contained a proviso, that I, the said John Leslie, shall cause a par-
ticular description of the nature of my said Invention, and in what manner
the same is to be performed, by an instrument in writing under my hand and
seal, to be inrolled in Her said Majesty's High Court of Chancery within six
calendar months next and immediately after the date of the said in part
recited Letters Patent, as in and by the same, reference being thereunto had,
will more fully and at large appear.
NOW KNOW YE, that in compliance with the said proviso, I, the said

page_text: John Leslie, do hereby declare that the nature of my Invention, and the
manner in which the same is to be performed, are fully described and ascer-
tained in and by the following statement thereof, reference being had to the
Drawings hereunto annexed, and to the figures and letters marked thereon,
that is to say:-
My Invention consists of three improvements, whereby the combustion of
gas for the purposes of light is rendered more efficient and beneficial.
The first improvement has for its object the use of apparatus by each con-
sumer suitably arranged for purifying gas, so as to ensure great purity; such
improvement consisting of the use of several different purifying matters on the
shelves or surfaces of the same dry purifying apparatus.
The second improvement consists of improved apparatus for ensuring the
gas being delivered to the burners at a more uniform pressure.
And the third improvement consists of improvements in the glasses of gas
burners, so as to improve and economize the combustion of gas for the purposes
of light.
the con-
And in order that my Invention may be most fully understood and readily
carried into effect, I will proceed to describe the means pursued by me.
And, first, in respect to purifying gas by apparatus employed
sumer, I am of opinion that the dangerous consequences to public health and
property from the products of combustion of impure gas require greater
preventatives than at present obtain, when, either from the transit of the gas
along long lines, of foul deposits in the main pipes, or from accident, or
negligence at the gas works, such impurities are distributed to the consumers,
and it so happens, that in the ratio which these impurities decrease the
illuminating power of the gas, so do they increase the danger to the health of
the consumer.
My improvement consists in using a purifyer, either circular, square, or
other convenient figure, attached to each supply from the street main.
Figure 1 shows a section of apparatus suitable for the first part of my
Invention. On either side of the centre division I place several perforated
trays D, fitting closely to the inner sides of the purifyer, each tray three or
more inches deep; these trays I fill with substances which absorb the more
deleterious and non-illuminative products of gas coal; the first, second, and
third trays I fill with sulphate or chloride of copper, or both, in separate trays,
the fourth and fifth trays with lime, I prefer to use blue lias lime, and the
sixth, seventh, and eighth trays with acetate of lead. From the close fitting
of the trays it is obvious that all the gas from the inlet must pass through the
various substances in the eight trays before it arrives at the outlet B.

page_text: I would remark that I believe the above to be the best arrangement of
a purifying apparatus when using several dry materials in the same vessel;
but the order in which the materials are placed may be varied, and other dry:
purifying substances may be employed with or in place of those above men-
tioned. And it should be understood that this part of my Invention does not.
consist in the use of any one of the above-mentioned substances, but in the
use of several dry purifying matters in the same vessel.
I will now describe the apparatus for ensuring a more regular supply of.
gas to burners, by which the combustion will be rendered more uniform, and.
therefore the gas will be more advantageously burned. The injurious con-
sequence of sudden increase of supply of gas from the street mains is well
known, occasioning foul carbonaceous deposits instead of illumination. My.
improvement consists in what I call an automaton gas economiser.
Figure 2 shows a section of this apparatus. A, inlet of gas; B, the only.
conducting tube to the outlet of gas; C, slide to increase or decrease the.
aperture of the conducting tube of gas, according to the number of lights to
be supplied. The stem of the slide works through a gas-tight stuffing box,
and has a pointer to indicate on the scale C' the amount of opening at C. D
represents an oil reservoir, as high as the dotted cross lines; E, dome, to
float in oil reservoir, with cone e at top; a small hole in the top cone e is
made to prevent the entire shutting off the gas by violent sudden pressure.
I will now describe the third part of my Invention. I use what I call glass
combustion chambers of the following configurations and capacities, as they
will tend to the more perfect combustion of different named quantities of gas,
and a consequent greater proportion of light will be the result. The form of
the glass by which the capacity is altered according to the quantity of gas
to be consumed varies only from the dotted line A, B, upwards, and the length
of the glass below the dotted line A, B, depends on the height of the tubes
of which my patent burner is composed, and which I prefer to use, although
this part of my
Invention is applicable when other gas burners are employed;
and I prefer that the glasses be so applied that the dotted line A, B, coincide.
with a line drawn across the apertures for the issue of the gas from the burner.
To illustrate the improvement,-if I want a burner to consume not more than
three cubic feet of gas per hour I apply the combustion chamber No. 1; if I
require more light, and wish to consume another cubic foot of gas per hour, I apply
the combustion chamber No. 2; and if I desire still more light, and to consume
five cubic feet of gas per hour, then I use combustion chamber No. 3, and so
on, increasing the capacity of the combustion chamber if larger quantities are
desired through the same burner. These various quantities of gas will in cach

page_text: case fill or nearly fill each of the combustion chambers from A, B, upwards with
a flame giving a greatly improved light.
greatly improved light. It will be found on testing that
the quantity of light from three cubic feet of gas, using combustion chamber
No. 1, is much decreased if No. 2 be used, and still more decreased if No. 3
be used; while, on the other hand, if a larger quantity of gas than is due to
the respective combustion chambers be admitted an injurious effect is pro-
duced. And it is important to be understood that this part of the Invention
depends on the use of peculiarly formed glasses, the capacity of which deter-
mines the extent of the quantity of gas which can be most usefully consumed
by a burner, for I have discovered that capacity as well as the shape shown
materially influences the most useful combustion of gas for the purpose of
light.
Having thus described the nature of my Invention, and the manner in
which the same is to be performed, I would state that I do not confine myself
to the details herein shewn and described, so long as the peculiar character
of either part of my Invention as herein described be retained.
In witness whereof, I, the said John Leslie, have hereunto set my hand
and seal, this Twenty-second day of September, in the year of our
Low One thousand eight hundred and forty-seven.