Improvements in the Construction and Ventilation of Gas Lamp Lanterns.
Year: 1898

page_text: Date of Application, 8th Jan., 1898-Accepted, 12th Feb., 1898
COMPLETE SPECIFICATION.
Improvements in the Construction and Ventilation of Gas Lamp
Lanterns.
I, WALTER RALPH HERRING, Chief Engineer and Manager of the Edinburgh &
Leith Corporations Gas Commissioners, New Street Works, Edinburgh, do hereby
declare the nature of this invention, and in what manner the same is to be performed,
to be particularly described and ascertained in and by the following statement:-
This invention relates to improvements in the construction and ventilation of
gas lamp lanterns and has for its object to prevent the flickering light produced
in windy weather of a gas flame burning within a lantern for ordinary outdoor
lighting purposes, and particularly to permit of the incandescent burner and mantle
being employed for outdoor purposes with or without the aid of a chimney or other
protecting medium. Hitherto the ventilation of a street lantern has been brought
about simply by a series of perforated discs or cylinders, baffle plates or louvres
communicating with the outside air, but the slightest draught caused back currents
and down draughts into the lantern and prevented the flame from burning with that
uniformity and efficiency which it otherwise would do if the lantern were constructed
so as to prevent external air currents from beating upon the flame. To accomplish
this object I employ a thin disc of talc or other noncombustible material resting
upon the top of the outlet funnel or flue, leading from the interior of the lantern.
The disc is held in the central position over the aforesaid flue by being threaded
upon a central stem or pin. Outside of this flue and projectng about 2" above the
level of the aforesaid disc, I carry up a casing of metal, and cap it with any form
of ornamental finish or finial that will prevent the rain falling through upon the
disc. The effect of this arrangement is as follows:
When the lantern is out of use, that is, the flame not burning, the disc rests upon
the top of the flue communicating with the interior of the lantern and completely
closes it to either wind or dust. Upon the lighting of the lamp the heated air
rises and possesses sufficient inertia to lift the disc and permit of the escape of the
products of combustion. In the event however of a passing current of air finding
access to the upper part of the lantern the disc momentarily closes and prevents
the disturbance of the inner flame immediately lifting again when the down draught
pressure of air current has ceased to exert itself, which as is well known is only
momentarily. However frequently it may occur the disc responds and during a
period of heavy storm would be in a constant state of lifting and closing, but which
nevertheless is quite sufficient to permit of the proper and free ventilation of the
lamp.
But in order that my said invention may be more readily understood and easily
carried into effect I have hereunto appended an explanatory sheet of drawings
in which: :-
Fig. 1 is an elevation partly in section and
Fig. 2 a plan, with a portion of the finial or cap removed, of a gas lamp lantern
constructed in accordance with my invention.
In the said drawings A represents the flue by which the products of combustion

page_text: escape. B the floating disc of mica, talc or other noncombustible material, which
covers the said flue. C the pin by which the disc B is guided in its up and down
movement and retained in its proper position. D the outer metal casing surrounding
the flue A and E the ornamental cap or finial by which the disc B is protected
from rain.
Having now particularly described and ascertained the nature of the said object
and in what manner the same is to be performed, I declare that I am aware of the
specification of W. P. Buchans Patent No. 2745 of 1878 and also of J. F. Simmance
No. 18801 of 1889, and I lay no claim to anything described or claimed therein,
but what I do claim is: —
The application of a floating disc of talc or other non-combustible material to
the flue of a gas lamp lantern, arranged and operating substantially in the manner
as hereinbefore described and shewn in the accompanying drawings:
Dated this 90th day of December 1897