OF THE MANUFACTURE OF GAS, 



89 



WHITES PROCESS APPLIED TO COALS AND CANNELS. 



The following experiments were conducted at the same 

 works, and with the same apparatus as those on the process 

 applied to resin ; but in order to obtain a fair comparison of 

 the results yielded by the various coals when distilled alone, 

 as in the usual process of gas making, with those obtained 

 from the same coals when treated with water gas, according 

 to the new process, each coal was distilled first by itself, and 

 then with the addition of water-gas, equal weights being 

 used for each experiment ; but as smaller quantities of gas 

 were produced in these experiments than in the previous 

 ones on resin, it was necessary to avoid any error which 

 might arise from intermixture of the gases filling the small 

 refrigerator, purifiers, &c., between the retorts and the 

 holder, previous to the commencement of each experiment, 

 and therefore the capacity of these vessels was determined, 

 and a quantity of gas considerably greater than requisite to 

 fill them, and made under the same circumstances as that in 

 the succeeding experiment, was passed through them before 

 each trial commenced. This plan of clearing out the vessels 

 and pipes was found to answer perfectly on testing it by 

 passing alternately similar quantities of Wigan cannel gas 

 and water-gas through them, and the observation of the num- 

 ber of feet indicated by the meter before the flame of a test 

 burner, coming from the ingress pipe near the holder, fully 

 assumed the illuminating power of the gas which was being 

 produced. 



This precaution being adopted, each experiment was com- 

 menced by charging one of the retorts, thoroughly cleaned 

 out, with 1 cwt. of coal or cannel, which was distributed 

 nearly equally between the upper and lower divisions ; the 

 lid being then replaced as quickly as possible, the distillation 

 was continued, either with or without the addition of water 

 gas, until all volatile matters were expelled from the coal 



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