different kinds of Coal-gas Burners^ ^-c. 223 



In these trials the results so far agree with those obtained 

 by argands, viz. that, when the flame is low, the gas is not so 

 profitably consumed as when it is high ; the air most probably 

 being supplied too freely, by which the gas is not sufiiciently 

 decomposed before it is burned. 



The results also shew, that, for equal consumpts, the bat- 

 wings do not afford so much light as good argands. Taking 

 the jet as 100, the argand gave a light as about 180 ; whereas 

 the bat-wing did not exceed 1G4, for equal consumpts. 



The next burners tried were fish-tails, or the decussating 

 jets. In this burner, the apertures, of the same diameter as 

 those in the single jets, pass in a slanting direction out from 

 the tube of the burner, and as the gas rushes out, it is, as it 

 were, twisted round, so that a line passing along the flame is 

 diagonal to one passing in the direction of the holes. 



The standard jet, as usual, burning one foot per hour. The 

 fish-tail was made to burn so as to give the full flame, but 

 without any flickering. 



In the first trial, 



Consumpt, . 1 jet to 2.3 fish-tail 

 Light, . . 1 ... 3.16 

 And 2.3 : 3.16 : ; 1 : 1.37— Gain 37. 



In another, 



Consumpt, . 1 to 2.14 

 Light, . . 1 to 2.98 

 And 2.14 : 2.98 : : 1 : 1.39— Gain 39. 



In a third trial, 



Consumpt, . 2.18 

 Light, . . 3.16 

 And 2.18 : 3.16 : : 1 : 1.40— Gain 40. 



Numerous other trials of a similar nature were made with 

 fish-tails^ from which I have found that the gain, by using this 

 burner instead of the jet, is, on an average, about 40 per cent. 

 It is of the utmost consequence, however, to be careful in keep- 

 ing the apertures clean, more especially when the flame is 

 burned low, as in bed-rooms, when it is wished during night 

 merely to keep it burning. In this case the holes are apt to 

 become clogged with a carbonaceous deposit, and the gas is 

 then burned unprofitably ; indeed this is the case with almost 

 all burners. 



