2(34 
a double current of air, or an Argand’s lamp. I have ofteia 
measured the intensity of its light, by means of my photo* 
meter, and have found it from 3800° to 4000°; therefore it 
equalled the light of 38 or 40 good candles, burning all 
together, and with their greatest brilliancy. 
M. Professor Pictet, inspector general of the imperial 
university, and M. Micheli, of Geneva, assisted in an ex¬ 
periment made at my house, at Antenil, some days ago, 
when this lamp afforded us more than 3800° of light. And 
M. Guy Lussac, member of the institute, was present at 
another experiment which gave 4000° of light. On this 
last occasion we compared the flame of this new lamp with 
that of an Argand’s lamp, in order to see which was the 
most beautiful. The two lamps having been placed near 
each other, we were struck with the result of the compari¬ 
son. The flame of the Argand lamp appeared as yellow 
and dull at the side of the new lamp, as that of a candle by 
the side of an Argand lamp. 
The most important circumstance in this invention is, 
that we can give to these new polyflame lamps any degree 
or power of illumination we wish, and can be certain of 
having more light from a given quantity of oil, than from 
any lamp hitherto known. 
The fundamental principle on which this lamp is con¬ 
structed is so obvious, that it requires only to be mentioned 
to understand how to put it in practice in every instance. 
We have only to preserve the heat of the flame as much 
or as long as possible. How is it obvious that a very simple 
contrivance will accomplish this ? It is by placing a number 
of flat wicks close to each other (large or small), in order 
that, uniting together, they may cover each other, and mu¬ 
tually defend themselves from the surrounding cold bodies. 
A flame being perfectly permeable to another flame which 
crosses it, as I have shown already, there is no danger that 
a flame in covering another, will diminish the brilliancy of 
the light which it sheds. I have made the light of a flame 
