378 Scientific Proceedings, Royal Dublin Society. 
At first sight it may appear a very easy thing to keep a lamp 
burning for any length of time by what would seem the obvious 
expedient of giving it a sufficient and continuous supply of oil; but 
if anyone will try the experiment, he will find that at the end of a 
few days the wick will have become so charred as to obstruct the 
capillary attraction which brings the oil to the point of combustion, 
and the light will go out. 
A carbonised wick has been devised, of which a sample was 
shown, which lasts longer than an ordinary wick, but even with 
that wick the deposit from the oil after some days’ burning is 
sufficient to extinguish the light. ; 
It occurred to me that if it were possible to cause the wick to 
move so that the same part of it would not be constantly exposed 
to the action of the heat of the combustion 
this difficulty would be got over, and a con- 
tinuous light secured. I tried many plans 
to this end; some of them, though success- 
ful, were complicated and expensive. I 
therefore abandoned them, and at last hit 
upon the method described in the present 
Paper. 
In an ordinary paraffin burner, the 
wick, as we all know, is perpendicular to 
the level of the oil in the oil container 
and draws its oil vertically from it, but a 
wick applied in this way could not readily 
be made to alter its position automatically 
as its combustion proceeded. I therefore 
devised the plan of burning the wick 
horizontally, passing it slowly over a 
small roller, thus obtaining the ight from 
the side and not from the end of the wick. 
The experimental apparatus by which 
this plan was worked out was exhibited 
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how the wick was used. 
The drawing (fig. 1), shows the form 
of the lamp as it is used in practice. A fountain supplies the 
lamp with a sufficient supply of oil at a uniform level for the 
Fig. 1. 
