THE PHILIPPINE 



Journal of Science 



A. General Science 



YOL. lY MAY, 1909 No. 



CALORIMETRY, AND THE DETERMINATION OF THE CALO- 

 RIFIC VALUE OF PHILIPPINE AND OTHER COALS FROM 

 THE RESULTS OF PROXIMATE ANALYSIS. 



By Alvin J. Cox. 



(From the Laboratory of Inorganic and Physical Chemistry, Bureau of 

 Science, Manila, P. I.) 



Many engineers are accustomed to judge of the steaming quality of 

 coal from its specified heating value ^ rather than from the analysis of 

 the fuel. To determine this a steaming test is not satisfactory, because 

 different furnaces give different values and the jDersonal equation of 

 firing and manipulation enter to a large degree into the results. Steam- 

 ing tests are useful only for comparative purposes and then only when 

 they are carried out in identical apparatus and under like conditions. 



The only absolutely reliable means of determining the heating value 

 of a coal is by the use of a standard calorimeter which records accurately. 



There are many kinds of calorimeters " of varying accuracy, some of which shovy- 

 discrepancies of as much as 15 per cent and are seldom if ever used. In general, the 

 large apparatus is to be condemned, because it is impossible to detect the errors 

 which creep in and to make allowance for them. This is not the place to descri.be 

 the difficulties and defects connected with these calorimeters. In all cases the 



'^ The heating value of a coal is expi'essed in calories. A calorie . is the 

 amount of heat necessary to raise the temperature of 1 gram of water 1° C. The 

 "pound calorie" is sometimes used by English writers; it is the amount of heat 

 necessary to raise the temperature of 1 ponnd of water 1° C. The figures would 

 be the same in either ease, for when the heating value of a coal is given in calories 

 it means that 1 gram of coal will heat the given number of grams of water 1° 

 C. or that 1 pound of coal will heat the given niunber of pounds of water 1° 

 C One British thermal unit is the heat necessaiy to raise 1 pound of water 1° 

 F., therefore, 1 calorie=9/5 B. T. U. 

 the end of this article. 



- A bibliography of the literature of calorimeters, arranged alphabetically, is 

 given at the end of this article. 



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