REVIEWS 653 



Asbestos manufacture is a new industry in the Philippines. At 

 present only one district — that of Ilocos Norte — is productive. Both 

 amphibole and chrysotile asbestos are known. An asbestos plant is 

 now operating in Manila. 



Oil exploration is so far merely preliminary and confined to the Lake 

 Lanao-Cotabato district (Mindanao) and to the Tayabas field. The 

 Mindanao oils have a specific gravity of .93 to .91 as analyzed; the base 

 is paraffin. 



Sulphur is found in solfataras and in the impure state, mixed with 

 volcanic ash, in several localities. The production of cement has 

 virtually ceased because of the failure of the largest cement plant. 

 Fire-clay, lime, sand and gravel, stone, salt, and mineral and artesian 

 waters are the other resources treated. A separate chapter is devoted 

 to glass-making; this demonstrates the accessibility of all the material 

 necessary to the process — lime, silica, and alkali. 



The report urges the revision of the federal mining laws and the 

 establishment of a school of mines. The adoption of a leasehold system 

 is advocated; present mining law in the Philippines requires that 200 

 pesos worth of development be performed annually on located, unpat- 

 ented claims, which "does not always accomplish the purpose sought 

 either by the Government or the claim holder." 



The report contains a directory of mine-owners, lessees, and operators, 



and a transcript of the mining laws of the Philippine Islands. Several 



good photographs accompany the report, but unfortunately others are 



carelessly moimted- — possibly the error of the publisher — and still others 



show little or nothing of the very features they are presumed to illustrate. 



Some of these shortcomings may no doubt be laid at the door of the 



smallness of the funds available, which has compelled a reduced staff 



to disperse its energies over a large field. Similarly, no doubt, the 



general lack of detailed geological descriptions may be accounted for. 



All in all, the report is of distinct value. 



C. H. B., Jr. 



Deposits of Manganese Ore in Costa Rica and Panama. By Julian 



D. Sears. Bulletin 710-C, United States Geological Survey, 



Government Printing Office, Washington, D.C., 1919. Pp. 



31, pis. I, figs. 28. 



This bulletin is actually two separate papers — one dealing with the 



manganese of Costa Rica, the other with that of Panama. 



The known manganese deposits of Costa Rica are all in the Province 

 of Guanacaste, on the Pacific Coast. They are widespread, but generally 



