[.—Chemical analyses ol the two samples of coal 

 se specific gravities are given on p. 337, have been 

 e by Mr. L. Wright of the Chemical Department, Uni- 

 tity of Sydney, with the following results : — 



No. 1. No. 2. 



Moisture ... 



Volatile hydrocarbons . 



.. 1'07 

 .. 25-13 



1-18 

 22-77 



Fixed carbon 



.. 62-12 



65-53 



100*00 100-00 



From these results it is apparent that the compression 

 and hardening of the coal is almost entirely a mechanical 

 process. Contrary to expectation the rise in fixed carbon 

 and corresponding decrease in volatile hydro-carbons is 

 very small. If much heat had been developed in the form- 

 ation of the roll, the coal would certainly have given 

 evidence of the fact in distillation of the volatile con- 

 stituents. We may conclude, then, that the expansion in 

 the floor rocks was very gradual. I desire to express my 

 thanks to Mr. Wright for his kindness in making these 

 analyses. 



