268 



Dr Andrew Fyfe on the Comparative Value of 



The following Table gives the results with gases ft'om 

 Scottish parrot coal : — 



In the above tables, the experimental results very nearly 

 agree with those given by calculation ; and, accordingly, we 

 may consider the consumpt of different gases, from similar 

 burners, and under similar circumstances, to be as the square 

 roots of the pressures necessary to burn them, under these 

 circumstances; of course, the times required for the con- 

 sumpt of equal volumes will be inversely as the roots of the 

 pressures. 



Another important circumstance still remains to be ascer- 

 tained, viz., as the pressure necessary for the consumpt of 

 the gases varies, and as the consumpt also varies with the 

 specific gravity. Is there any connection between the specific 

 gravity of different gases and the pressures necessary for 

 their consumpt, under similar circumstances 1 



The following table gives the results of the consumpt of 

 gases under similar circumstances, along with the pressures 

 and the specific gravities, taken in the usual way. 



