215 
sessing a lamp, which may be made to burn with as small 
a llame as is desired, and that without any smell. In this 
way it may be used as a rush light, and in case of necessi¬ 
ty, a light equal to that of one and indeed two candles, may 
be obtained in an instant. 
The quantity of light furnished by this lamp, depends on 
the kind of wick which is used. I have tried several kinds, 
and the one that appears to me best calculated for common 
purposes, is a flat wick, about an inch or thirteen lines in 
breadth and a line thick. It necessarily takes the form of a 
tube, a little open at one side when entering the wick hole, 
and it may be given this form at first, as it will favour its 
easy introduction. This may be done when it is dipped in 
warm melted tallow, it is afterwards rounded at the moment 
of use, on a small stick of wood or metal, of about two lines 
in diameter. 
To facilitate an operation which is always disagreeable 
and filthy, that of renewing a wick, I have adopted an in¬ 
vention already known, which appears to me very ingen¬ 
ious ; it was proposed to me by M. Hadrot, tinman,* a 
very ingenious mechanic, who I have employed to manu¬ 
facture my portable lamps. It is as follows, a straight 
round piece of strong brass wire, a line and an half in di¬ 
ameter, and three or four inches long, is attached firmly at 
its inferior part, to the lower extremity of the racket, and 
rests on the axis of the supporter of the lamp ; the upper 
part entering by a collar of copper across the flat bottom of 
the wick pipe, has, at its superior extremity, a small lever, 
composed of three elastic hooks, of a minute size : they are 
of such a form, that when by means of the racket, the 
piece of wire is made to ascend sufficiently to permit them 
to pass out through the opening of the wick at its superior 
extremity, they will seperate spontaneously and seize hold 
of the remains of the old wick and retain it by its extremity 
* Rue St. Sauveur, No. 43 . 
