230 Dr Fyfe on the Illuminating and Heating Power of 



In the above, the results with the jet and argand nearly 

 agree with the former. Those with the fish-tail and bat-wing, 

 though they coincide with themselves, yet do not agree with 

 the others. In the two first, the whole of the gas was con- 

 sumed ; in the two others, there was occasionally a little smoke, 

 which may account for the deficiency. 



The following trials were made with the 42~holed argand, 

 at various heights of flame, a quarter of a foot of gas being 

 used. 



In all of these, with the exception of the last, the heat 

 evolved was exactly proportionate to the consumpt of gas. 

 In the last, we may account for the deficiency by the time re- 

 quired, in consequence of which part of the heat that the wa- 

 ter had gained must have been given off to the surrounding 



an*. 



From the experiments »that have been given, there can, I 

 think, be no doubt with regard to the conclusion to be drawn, 

 — that the heating power of the different kinds of burners now 

 in use, is just in proportion to the quantity of gas that they con- 

 sume, provided of course the combustion is perfect ; in other 

 words, it is of no consequence whether the gas is consumed 

 with previous decomposition so as to give much light, or with 

 a bluish flame aflbrding little light ; the heat is always the 

 same for equal consumpts. Experiments to be afterwards 

 mentioned, will still farther prove the truth of thii^. Allowing 

 that this is the case, it is evident that, when gas is used solely 



