number of tubes. The opening T is furnished with a leather box, through
which passes the rod, Fig. 3. intended for raising and lowering the wick
of the lamp, as will be afterwards directed. The three other holes are
intended for the passage of three several tubes, one of which conveys
the oil to the lamp, a second conveys air for keeping up the combustion,
and the third carries off the air, after it has served for combustion.
The lamp in which the oil is burnt is represented Fig. 2; a is the
reservoir of oil, having a funnel by which it is filled; b c d e f g h
is a syphon which conveys the oil to the lamp 11; 7, 8, 9, 10, is the
tube which conveys the air for combustion from the gazometer to the same
lamp. The tube b c is formed externally, at its lower end b, into a
male screw, which turns in a female screw in the lid of the reservoir of
oil a; so that, by turning the reservoir one way or the other, it is
made to rise or fall, by which the oil is kept at the necessary level.
When the syphon is to be filled, and the communication formed between
the reservoir of oil and the lamp, the stop-cock c is shut, and that
at e opened, oil is poured in by the opening f at the top of the
syphon, till it rises within three or four lines of the upper edge of
the lamp, the stop-cock k is then shut, and that at c opened; the
oil is then poured in at f, till the branch b c d of the syphon is
filled, and then the stop-cock e is closed. The two branches of the
syphon being now completely filled, a communication is fully established
between the reservoir and the lamp.
In Pl. XII. Fig. 1. all the parts of the lamp 11, Fig. 2. are
represented magnified, to show them distinctly. The tube i k carries
the oil from the reservoir to the cavity a a a a, which contains the
wick; the tube 9, 10, brings the air from the gazometer for keeping up
the combustion; this air spreads through the cavity d d d d, and, by
means of the passages c c c c and b b b b, is distributed on each
side of the wick, after the principles of the lamps constructed by
Argand, Quinquet, and Lange.
To render the whole of this complicated apparatus more easily
understood, and that its description may make all others of the same
kind more readily followed, it is represented, completely connected
together for use, in Pl. XI. The gazometer P furnishes air for the
combustion by the tube and stop-cock 1, 2; the tube 2, 3, communicates
with a second gazometer, which is filled whilst the first one is
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