IMPROVED APPARATUS FOR INCREASING THE ILLUMINATING POWER OF GAS
Year: 1882

page_text: LETTERS PATENT to Francis Herbert Wenham of 16 Warbeck Road
Shepherds Bush, in the County of Middlesex, Consulting Engineer, for an
invention of "IMPROVED APPARATUS FOR INCREASING THE ILLUMINATING
POWER OF GAS."
(Void by reason of the Patentee having neglected to file a Specification in
pursuance of the conditions of the Letters Patent.)
PROVISIONAL SPECIFICATION left by the said Francis Herbert Wenham
at the Office of the Commissioners of Patents on the 28th March 1882.
FRANCIS HERBERT WENHAM, of 16 Warbeck road, Shepherds Bush, in the
County of Middlesex, Consulting Engineer, "IMPROVED APPARATUS FOR INCREASING
THE ILLUMINATING POWER OF GAS
Gas is conveyed downwards through a vertical pipe, to a burner perforated with
slits, or small orifices at the under end.
The burner may be of various forms, but I prefer an annulus of orifices, known
as the "Argand burner.".
The gas pipe passes down through a metal chimney, preferably made cylindrical.
In the bottom end of this is attached an inner cylinder of smaller diameter, which
may be less than half the length of the chimney, and is closed at the top, through
which the gas pipe passes.
Outer air is admitted into the cylinder, by side passages or tubes, let through
corresponding openings in the side of the chimney. The lower end of the inner
cylinder is made conical, with the opening somewhat exceeding the diameter of the
argand or other burner, and projects a little distance below it.
The base of the chimney has attached to it, or else rests upon a flange, which
forms a cover for the glass of the lamp; this may be globular or of the well known
form made up of separate plates, but the glass work however framed together
should be air tight.

page_text: The action is as follows:-The gas is ignited either by turning the glass globe
back on a hinge at the flange, or by passing a light up through a small trap-door
at the bottom of a glass globe or cylinder form of lamp, or if this is a framed one,
by opening a door therein. When this is closed, the hot air from the combustion
of the flame ascends into the chimney through the annular space around the inner
cylinder; at the same time air required for supporting combustion descends
through the side passages 'and inner cylinder, wherein it becomes heated. The
draft from the chimney causes the hot air from the inner cylinder to be drawn
down with considerable volocity, and impinging upon the frame, directs it
straight downwards into the lamp. The hot products of combustion escape
upwards into the chimney, by rising outside the flame, and, by preserving the
intensity of the heat, increases the brilliancy of the light. The flame is thus fed
with heated air, and is also enveloped by all the return heat derived from its
own combustion, and the carbonaceous particles, from the gas are more intensely
ignited thereby.
Around the base of the chimney, and ending above the side passages into the
inner cylinder, is a casing made air tight at the top junction with the chimney, but
with air orifices below at the crown plate of the lamp, the outer air first rising
through this economises heat, and the passages are shielded from gusts of wind
that might cause the light to be unsteady.
If glass globes are used, the lamp is shadowless, there being nothing beneath the
flame to impede the perpendicular direction of the light downwards.