different kinds of Coal-gas Burners^ 6sc. 



229 



cessary, therefore, to attend to this, so as to secure the com- 

 plete combustion of the gas, which is done by bringing the 

 burner a little lower. In the comparative trials, the same 

 quantity of water at the temperature 45, was put into the 

 boiler, which was always covered with a lid. Of course the 

 flame of the gas was at different distances from the bottom of 

 the boiler, according to the kind of burner used, and according 

 to the length of the flame. 



The first experiments were made with jets, fish-tails, bat- 

 wings, and argands, burning under- most favourable circum- 

 stances for affording light. For equal consumpts of gas, the 

 experiments on the illuminating power have shewn, that, taking 

 the jet as the standard, and giving light as 100, the fish-tails 

 give light as 140, the batwings as about 160, and the argands 

 as about 180. In each experiment, a quarter of a gallon of 

 water at 45° was put into the boiler, and half a foot of gas was 

 consumed by each burner. The temperature of the room va- 

 ried from 58° to 62°. 



The results of these experiments do not exactly coincide, 

 but as the flames of some of the burners were more within the 

 cavity of the boiler than others were, there may have been a 

 slight loss of heat by radiation. Supposing this to be the case, 

 it would appear that the heating power is not affected by the 

 same circumstance as the illuminating power ; that, in other 

 words, the heat afforded by different kinds of gas-burners is 

 not in proportion to the light they afford, but to the quantity 

 of gas they consume. Whether or not this was the case, was 

 to be proved by farther trials with the burners used in different 

 ways, so as to make them consume different quantities of gas 

 in the same time, or to require different times for the same con- 

 sumpt. In the following trials the gas used was half a foot. 



