TWELFTH ANNUAL REPORT g;[ 



THE NONMETALS 



The production of nonmetals in 1912, by Wallace E. Pratt. 

 General features of coal mining in 1912, by F. A. Dalburg. 



SPECIAL ARTICLES 



Petroleum on Bondoc Peninsula, Tayabas, by Wallace E. Pratt and Warren 



D. Smith. 

 Sand-lime brick and artificial sandstones in the Philippines, by Alvin J. 



Cox, W. C. Reibling, and F. D. Reyes. 

 Contribution to the metallogeny of the Philippines, by Paul R. Fanning. 



The details of papers which have been prepared and published 

 in The Philippine Journal of Science will be found in another 

 place under that head, but especial attention may be directed to 

 the following research completed during the year: 



Ore-testing investigations. — Many important laboratory tests 

 looking to the most efficient treatment of Philippine gold ores 

 have been carried on. Tests have been made on samples sent 

 in from three properties in Masbate, samples from the Paracale 

 dredges, and from Benguet. This work has been supplemented 

 by extended operations at the mills and on the dredges, and the 

 operation of one mill was studied for one month with the result 

 that it was shown where considerable savings and improvements 

 could be made, 



Tayabas oil fields. — The most complete survey ever made of 

 any of the prospective oil fields in the Philippines has been 

 completed in Tayabas Province. 



Natural gas. — A well, reported to be emitting large volumes 

 of natural gas at Oas, Albay Province, was examined. The 

 public interest was so great that the matter was looked into in 

 spite of our anticipation that it was a pocket of swamp gas, 

 which proved to be true. 



Neiv reservoir- site for the city of Manila. — A very careful and 

 important examination of a proposed reservoir site for the city 

 of Manila near Mariquina has been made. This work involved 

 questions of seepage, supports for an earth-fill dam, and material 

 for such dam. The results are greatly appreciated by the water- 

 works engineers, and demonstrate the value of careful geologic 

 investigation with reference to engineering projects. 



Geologic and toj)og}-aphic ivork in Mindoro. — Geologic and 

 topographic notes to be incorporated in the main report of a 

 medical survey of the San Jose estate in Mindoro have been 

 made. 



Palawan. — A second geologic exploration trip to Palawan fur- 



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