CHAPTER VII. 

 SOLID FUELS. 



COAL. 



AMONG the first careful tests ever made, to determine the 

 heat value of different kinds of coal, are those made in 1843 an d 

 1844 by Prof. W. R. Johnson for the U. S. Navy. He 

 analyzed and tested all the kinds obtained from the United 

 States and England, which were then in use by the navy. 

 At the time they were made the calorimetric determinations 

 were not considered as of the importance they are now, 

 and his tests were limited to determining the evaporative 

 power of the coals. Mr. W. Kent reviewed them in the 

 Engineering and Mining Journal, 1892, and showed that up to 

 the time of the experiments nothing comparable with them 

 had been attempted, and that in many respects they compare 

 favorably with work done to-day. 



In 1857 Morin and Tresca made numerous determina- 

 tions of the calorific power of coal and wood, and in 1853 

 they published a work on " Fuels and their Calorific Power," 

 in which they make many recommendations for more accurate 

 work. They wrote: " It would be extremely important if 

 experiments with the calorimeter could be made on most of 

 the fuels, by methods similar to those used by Favre and Sil- 

 bermann." 



In 1868 such experiments were made by Scheurer-Kest- 

 ner, and continued by him later with the aid of Meunier- 

 Dollfus. They based their calculations on pure coal, i.e., with 

 moisture and ash deducted. This method, which has been 



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