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About two lines beneath the inferior extremity of this 
trumpet-formed tube, the supporter is bored with a row of 
oblong holes, which give passage to the air that nourishes 
the flame of the lamp, and it is through one of these holes, 
that the button which moves the racket, passes, and by 
means of which, the wick is raised or depressed. 
It will be seen from the description hereafter to be given 
of the reservoir, that as long as the lamp stands steady and: 
perpendicular on its base, the oil in the handle will flow 
freely towards the wick pipe ; but that as soon as it is mov¬ 
ed, if the extremity of the handle happens to be higher than 
the opening of the wick pipe, the oil in the handle will de¬ 
scend to the side which is lowest. Thus instead of empty* 
ing itself through the opening into the wick pipe, it will be 
intercepted by the partition, separating the reservoir, and 
remain retained in the handle. It is evident that the oil in 
this case cannot flow through the pipe concealed in the bot¬ 
tom of the handle, since its aperture will be found above 
the surface of it. 
To prevent the height of the oil in the wick-pipe from 
being affected by the motion given to the lamp in carrying 
it, it is made to pass into the wick pipe through a very 
small hole, about the fourth of a line in diameter, at its 
passage. This small opening ought to be in the partition 
of the wick pipe, and not in the bottom of the circular re¬ 
servoir, thus preventing its being exposed to stoppage from 
the bubbles of air which might adhere to it. 
There is another accident to be apprehended, and against 
which it is proper to be guarded. In order to supply the 
lamp reservoirs with air, and to facilitate the flow of oil 
into the wick pipe, it is necessary to leave an opening 
through which the air may pass. The most convenient sit¬ 
uation for this aperture, is in the middle of the stopper to 
the passage by which the lamp is supplied with oil, and here 
I have placed it. I bored a hole in the centre, about a line 
in diameter, and placed in it a small vertical pipe of the 
W 
