132 The Philippine Journal of Science 



The second run was much more satisfactory. The temper- 

 ature of the gas issuing from the stack was very greatly reduced 

 with a corresponding decrease in the average coal consumption 

 of 10.2 per cent. The average output of the kiln was increased 

 to nearly 1 metric ton per twenty-four hours. The results of the 

 gas analyses show an excess of air, admitted by the warped fire 

 doors, which did a great deal to reduce the efficiency of the kiln. 

 With properly fitted doors the coal consumption could easily be 

 further reduced from 5 to 10 per cent. 



Wood, consisting of thin strips of air-dried lumber and waste, 

 was used on the last day of the second run. The amount of 

 wood consumed is very small when it is considered that this wood 

 has only about half the calorific value of coal. Wood is better 

 adapted to lime burning than most coal, for it has a longer flame. 

 The thermal conductivity of lime is very low, and the flame 

 must surround the rock to give the best results. Where wood 

 can be obtained, it is preferable, but in many places only coal 

 is available. Information with regard to the value of Philip- 

 pine firewood has been published by Cox.^ The characteristics 

 of some Philippine coals that are available for use in lime kilns 

 are given by the same author.^ 



The kiln has served its purpose in demonstrating kiln require- 

 ments suitable for local lime burning and in forming the basis 

 for the design of the new kiln. 



[Editor's note. — Lime manufacture is more highly developed in some 

 places in the Philippine Islands than the outline of processes in the first 

 page of this report may indicate. For example, at Baguio large kilns are 

 built of limestone and the fuel and rock are kept separate so there should 

 be no contamination of the lime with ashes. The kilns require relining 

 from time to time, because fire brick are not available. The kilns are not 

 continuous, and there is considerable waste of fuel and labor.] 



'Ibid. (1911), 6, 1-22. 



'Ibid. (1909), 4, 211-229, and (1912), 7, 1-17. 



