32 Mr. Brande on the composition and analysis 
same dimensions as that of the single jet, and forming a circle 
0,7 inch diameter. The pressure being 0,5 inch, the flame 
was so regulated as to burn with its full intensity without 
producing smoke, and its light being measured by a com- 
parison of shadows, it was found equal to ten wax candles. 
The consumption of gas amounted to 2600 cubical inches, 
or about a cubical foot and a half per hour. 
If the result of this experiment be compared with the above, 
in which a single jet was used, it will appear, that the pro- 
portion of light from a given quantity of gas is increased in 
a very high ratio by employing many flames near each other, 
the consumption of the single jet giving a light of one candle, 
being = 640 cubical inches, whereas the Argand burner gave 
a light of ten candles, with a consumption not of 640 x 10 cu- 
bical inches, but of 2600 cubical inches. It will be remembered, 
that in the latter, the combustion is perfected by a central 
current of air, rendered more rapid by the glass tube which 
surrounds the flame. Count Rumford showed some time 
ago, “ that the quantity of light emitted by a given portion 
of inflammable matter in combustion, is proportional in some 
high ratio to the elevation of temperature, and that a lamp 
having many wicks very near each other, so as to communi- 
cate heat, burns with infinitely more brilliancy than the 
Argand’s lamps in common use.”* The construction of the 
gas Argand burner is particularly calculated to produce an 
effect of this kind ; and to such a cause the great increase of 
light relative to the consumption of gas may probably be 
attributed.'f 
* Davy’s Elements of Chemical Philosophy, p. 224. 
f In the annexed drawing (Plate III.) is represented an Argand burner for oil 
