IMPROVEMENTS IN ROOF LAMPS FOR RAILWAY CARRIAGES FOR BURNING HYDROCARBON OILS
Year: 1873

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PROVISIONAL SPECIFICATION left by Henry Harrison Doty at the
Office of the Commissioners of Patents, with his Petition, on the
25th April 1873.
I, HENRY HARRISON DOTY, of 15, Bury Street, St. James's, in the
County of Middlesex, Gentleman, do hereby declare the nature of the
said Invention for "IMPROVEMENTS IN ROOF LAMPS FOR RAILWAY CARRIAGES
FOR BURNING HYDROCARBON OILS," to be as follows:-
This Invention for improvements in roof lamps for railway carriages
for burning hydrocarbon oils, consists in the following arrangement of
the lamp. I make use of a conical oil reservoir, its base resting upon a
plate rather larger than this base; this plate is the foundation upon
which and by means of which the parts of the lamp are combined
together as follows:-Rising up from the base are two or three standards
the lower parts fixed to the base, the upper parts fitted with keys, pins,
or screws by which to attach the upper part of the lamp, namely,
reflector, chimney, handle, and flange that forms the support for
suspending the lamp.
the
The oil reservoir is made conical, its upper smaller part having the
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huway with the transzzomas onaning

page_text: for the flat wick single or double. Over this oil reservoir I place a thin
metallic cone leaving a small annular space between it and the oil
reservoir to which it nearly conforms in shape; this cone at the bottom is
slightly raised above the before-mentioned base by small raised pro-
jections on the base or other means, about one-eighth of an inch; the
bottom end of the cone has a level projection outwards forming a base
to hold the lower end of a glass cylinder; the upper end of the cone fits
tightly round the round cap burner before mentioned. Having placed
the oil reservoir upon the base I place over it the said cone and on the
level projection of the cone I place the glass cylinders about six inches in
height.
The upper part of the lamp is formed thus:-I take an ordinary
reflector of the common railway carriage roof lamp and making two or
three holes to admit the upper part of the standards rising from the base,
I put the reflector on these standards projecting through it, and let the
reflector rest upon the before named glass cylinder; I then by means of
the keys, pins, or screws of the upper part of said standards attach the
base glass cylinder and reflector firmly together. This attachment may
be made with or without packing between the upper and lower edges of
'the glass cylinder, and the metal; but I prefer a packing of leather or
some other similarly yielding material. Upon the reflector eovering its
surface is an outer case of similar form with similar openings similarly
held by the top fastenings of the standards, and to this outer case I..
attach the handle in the form of an arch or bow for carrying the lamp,
and to the bow or arched handles or to small standards I attach the
projecting flange for supporting the lamp in the roof of the carriage.
In the central opening of the reflector is fixed a chimney of metal
about 6 inches in height with a cap or cowl over it. From this
description it will be seen that the greater part of the air to supply the
flame must pass in at the base of the outer cone, and rise up between
the cone and the oil reservoir; and through the transverse opening in the
round cap the chimney from the central opening of the reflector forms
the draught by which the air is drawn up as thus described.