IMPROVEMENTS IN APPARATUS USED IN GAS LIGHTING
Year: 1863

page_text: LETTERS PATENT to William Renwick Bowditch, of Saint Andrew's, Wake-
field, in the County of York, Clerk, for the Invention of "IMPROVEMENTS
IN APPARATUS USED IN GAS LIGHTING."
Sealed the 1st March 1864, and dated the 11th November 1863.
PROVISIONAL SPECIFICATION left by the said William Renwick Bowditch
at the Office of the Commissioners of Patents, with his Petition, on
the 11th November 1868.
I, WILLIAM RENWICK BOWDITCH, of Saint Andrew's, Wakefield, in the
County of York, Clerk, do hereby declare the nature of the said Invention of
"IMPROVEMENTS IN APPARATUS USED IN GAS LIGHTING," to be as follows:-
One of my improvements consists in placing one or more perforated or
wire gauze diaphragms in vessels used to hold hydrocarbons employed for
carburetting gas, especially where such vessels are placed above the lights.
These diaphragms are so placed that the vapour of the hydrocarbons
They are of especial
rises up through them to mingle with the gas.
service when carburetting apparatus is used in carriages or vessels, or any
unsteady situations, as the placing of these diaphragms above the hydro-
carbons prevents communication of motion from them when agitated to
the mingled gas and vapour which are passing to the burner.
Another of my improvements consists in a method of removing from gas
lamps hot air and products of combustion by passing the same through
tubes communicating between the box or lantern which contains the light

page_text: and the external air. By this arrangement the lights are more effectually
protected from wind and currents of air than at present, and consequently
burn more steadily.
for this purpose is glass
When the glass is viewed
the glass, like the colours in what
When the glass
When the glass is used to form
outwards from the light, and the
light. White porcelain or milk
Another of my improvements consists in the construction of reflectors
for gas and other lights. The material I use
made with a white opaque enamel on one side.
in section, this enamel is seen united to
is known in trade as "flashed gas."
reflectors the enameled side is placed
unenameled side inwards towards the
glass or other similar reflecting material may be used instead of the above
described enamelld glass, if a sheet of ordinary window glass be placed
between it and the light, but I prefer glass enameled on one side only. The
insertion of glass between the white reflecting material and the light prevents
damage to the reflector by heat, smoke and dirt, and thus makes it more
efficient and durable than if unprotected.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said William Renwick Bowditch in the Great Seal Patent Office
on the 10th May 1864.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, WILLIAM
RENWICK BOWDITCH, of Saint Andrew's, Wakefield, in the County of York,
Clerk, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Eleventh day of November, in the year of our Lord
One thousand eight hundred and sixty-three, in the twenty-seventh year of
Her reign, did, for Herself, Her heirs and successors, give and grant unto
me, the said William Renwick Bowditch, Her special license that I, the said
William Renwick Bowditch, my executors, administrators, and assigns, or such
others as I, the said: William Renwick Bowditch, 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 APPARATUS USED IN GAS LIGHTING," upon the condition,
amongst others, that I, the said Willian Renwick Bowditch, by an instru-

page_text: ment 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 William Renwick Bowditch, 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 (that is to say):-
:
To carry out the first part of my Invention, I proceed as follows:-I place
one or more diaphragms of wire gauze or perforated metal in vessels used
to hold hydrocarbons employed in carburetting gas, especially in vessels which
are placed above the lights carburetted. These diaphragms are so placed that
the hydrocarbons may be below one or more of them, and while the vapour rises
freely to carburet the gas, the hydrocarbons are separated by at least one
diaphragm from the pipe which conveys the gas and hydrocarbon vapour to
the burner or burners. These diaphragms are of service when carburetting
apparatus is used in carriages or vessels, or in other unsteady situations, as
they prevent any unsteadiness being communicated to the gas by agitation of
the hydrocarbons. They are shewn at A, Figure 1 of the Drawings annexed
hereto.
Another of my improvements consists in a method of removing from gas
lamps used in carriages and vessels hot air and products of combustion. I
effect this by passing the same through tubes as shown at B in the Drawings
annexed hereto, communicating between the box or lantern which contains the
light and the external air. I find these tubes act most efficiently when they
are of about three-quarters of an inch in diameter, three inches long, and
placed at an angle of about forty degrees from the perpendicular with their
mouths (through which the hot air and gases pass) pointing downwards. By
this arrangement the lights are more effectually protected from wind and
currents of air than at present, and consequently they burn more steadily.
Another of my improvements consists in the construction of reflectors for
gas and other artificial lights. The material which I use for this purpose is
flint or other glass made with a white enamel on one side. Flint glass, being
less liable than other kinds to crack by heat, is to be preferred. When this
glass is viewed in section the enamel is seen united to the glass like the
colours in what is known in trade as "flashed glass." When the glass is used
to form reflectors the enamelled side is placed outwards from the light so that
it may not be smoked or otherwise injured by the light, and the unenamelled

page_text: side is placed inwards towards the light. White porcelain or milk glass or
other similar reflecting material may be used instead of the above-described
enamelled glass, if a sheet of ordinary window glass be placed between it and
the light, but I prefer glass enamelled on one side only. The insertion of glass
between the white reflecting material and the light prevents damage to the
reflector by heat, smoke and dirt, and thus makes it more efficient and durable
than if unprotected.
In witness whereof, I, the said William Renwick Bowditch, have here-
unto set my hand and seal, this Ninth day of May, in the year of our
Lord One thousand eight hundred and sixty-four.
Signed and sealed by the within-named
William Renwick Bowditch, in the
presence of
PHIL. G. SKIPWORTH,
Solicitor,
Wakefield.
W. R. BOWDITCH. (L.S.)