of certain inflammable gaseous compounds. 23 
4. The gasometer being filled with oil gas, an Argand 
burner, giving the light of eight wax candles, was found to 
consume 3900 cubical inches per hour ; and the same inten- 
sity of light was produced by the same quantit}^ of artificial 
oil gas ; that is, of a mixture of three parts of olefiant and 
one of hydrogen. 
5. The apertures of burners for coal gas require to be 
considerably larger than those for olefiant or oil gas. In the 
burner employed in the following experiments, each hole was 
~ inch diameter, and the circle upon the circumference of 
which they were placed, was 0,9 inch diameter. The light of 
the flame was found equal to five wax candles only, and the 
consumption of gas per hour amounted to 6560 cubical inches. 
With a mixture of six parts by measure of hydrogen with 
five of olefiant gas, the light of the flame was somewhat more 
intense ; and the quantity of gas consumed by the same 
burner, so adjusted as not to smoke, was 6000 cubical 
inches. 
6. It appears from the above data, that to produce the 
light of ten wax candles for one hour, there will be required, 
q6co cubical inches of olefiant gas. 
4875 - - - oil gas. 
13120 - - coal gas; 
gas, upon what I believe to be the most economical construction. The bevilling of 
the perforated edge contributes greatly to the perfection of the light, as shown in 
the section. Fig* i. The diameter of the circle of holes is 0,7 inch, and the holes 
should not be more than ^ of an inch in diameter. Consuming at the highest 
average 4000 cubical inches per hour, it gives the light of between eight and nine 
wax candles of four to the pound. 
Fig. 3 is a sketch of what is technically termed a rose burner ; it has six holes of 
the same dimensions as those of the Argand, and when so regulated as to produce a 
light equal to that of six wax candles, its greatest average consumption of gas 
amounts to 4800 cubical inches per hour. 
