70 



REPORT 1869. 



asterisk were selected as most econom cal, and the basis -was laid do-wn that the 

 coals, or mixtures of coals, shoidd yield 10,-'00 cubic feet of gas of 30-candle po-wer. 

 Calculations were made so as to observe what coals or mixtures of such ought to 

 yield the requisite quantity and quality of gas, and the coals were used in the defi- 

 nite proportions calculated to yield the best results. The second series of trials 

 proved that the illuminating-power of the gas obtained from the mixtures of coals 

 as determined by experiment was always in excess of that arrived at by calculation 

 from the quality of the gas yielded by the individual coals taken separately, as may 

 be observed from the following Table : — 



Gas from Cannel-Ooals taken separately and mixed. 



These results will probably be best conti-asted by throwing the quantity and 

 quality of the gas into lbs. of sperm, and the following Table gives the results of 

 the illuminating-power of the coals and mixtures as determined by calculation from 

 the yield of the individual coals taken separately, and the respective proportions 

 obtained by the distillation of the coal previously mixed, the value in each case 

 being given in lbs. of sperm. 



