226 Dr Fyfe on the Illuminating and Heating Power of 

 The slits were then enlarged a little, and the results were 



So that, for equal consumpt of gas, there was a gain varying 

 from 40 to 60 per cent. 



I consider a burner of this kind as extremely useful, where 

 no great degree of light is required. Not that I prefer it to 

 the large bat-wing, or even to the fish-tail, though it gives 

 more light than the latter for the same consumpt of gas ; but 

 for many purposes it may be found useful, as for street lamps, 

 instead of jets. 



In making these remarks on the comparative illuminating 

 power of gas-burners, I wish it to be borne in mind, that it 

 has not been my object to fix them with numerical precision. 

 It must be evident, from what has been said, that the state- 

 ments given must be considered merely as general results^ for 

 we must always recollect that the light afforded depends not 

 only on the kind of burner, but, even with the same burner, 

 on extraneous circumstances ; as the height of flame, the free- 

 dom of the burner from carbonaceous deposit, the form of 

 chimney when argands are used, and many others. 



It is not my intention at present to enter upon the practical 

 applications resulting from these experiments. I will refer to 

 them after detailing the experiments on the heating powers of 



