the regulator must be raised to such a height as entirely to 
conceal the wick. 
I have used this invention with the greatest success in 
adjusting the flame of lamps with spirits of wine, when 
used as chaffing dishes : It may be seen on the lamp which 
I have the honour to place before the class, but in oil lamps 
it will not prevent the unpleasant smell when they are 
extinguished. This is a defect common to all kinds of 
lamps, and will probably hinder the invention from being 
generally adopted, especially in low priced lamps. 
It will be observed, that my lamps, however differing in 
the shape of their wicks, are all constructed so as to re¬ 
ceive lamp-glasses. It is truly astonishing that this useful 
invention has not been long since universally adopted. It 
is now more than twenty years ago, since I have used it to 
enli ven and brighten the flame of lamps with twisted, round¬ 
ed or flat wicks. The flat wick may be perfectly enlivened 
without flattening its lamp^glass. But I must not at this time 
anticipate a subject, which I purpose examining in detail 
©n some future occasion. 
SUPPLEMENT. 
Since this memoir has been presented to the Institute, I 
have instituted several experiments to ascertain what form 
of wick is best for the portable lamp, and after several tri¬ 
als, have found that a flat one, moulded in the form of a 
gutter, on a cylindrical stick, is decidedly preferable to the 
cylindrical wick, recommended in the memoir, and which 
'is as certainly preferable to any in former use. 
When this wick (properly rounded) is inserted into the 
wick-pipe, it ought to be presented to the forceps in such 
a manner that its open side be turned towards the handle 
X 
