TWELFTH ANNUAL REPORT 



39 



of the most promising Philippine materials which are available 

 for concrete work in different localities. 



64. Nonmetallic deposits. — Field investigations have revealed 

 the existence of materials suitable for various purposes and of 

 economic importance; for example, asbestos and sulphur depos- 

 its ; limestones ; sand ; volcanic tuff and ash ; clays and shales 

 suitable for the manufacture of Portland cement, hydraulic 

 cement, sand-lime brick, vitrified brick, refractory ware, and 

 pottery; and stone suitable for lithographic purposes. In the 

 calendar year 1912 the importations of china-, earthern-, and 

 stoneware alone amounted to ^=391,852, of which 50 per cent could 

 easily be produced in the Philippines. The importations of Port- 

 land cement for the same period amounted to =P=1, 136,456. 



65. Sand-lime brick and artificial sayidstones. — A study of 

 available local materials and conditions showed that the latter 

 in the Philippines are very favorable for the manufacture of 

 brick and artificial stone from sand and lime; that the best 

 location for the first plant is probably in the vicinity of Manila 

 near Pasig River at Guadalupe; that strong, dense, durable, 

 impermeable, and practically fireproof sandstone could be made 

 by the steaming process from sands from Manila beach, Pasig 

 River, and Orani River, and from Tarlac volcanic tuff, quarry 

 debris from Sisiman (andesite), or Talim (basalt) rock; that 

 the beach sand was the most economic material; that beautiful 

 polished "marbles" could be manufactured from the quarry de- 

 bris ; that the cost of manufacturing and selling 9-inch bricks of 

 the best quality would not exceed TIZ per thousand ; and that the 

 profit of a plant could be increased by extending its operation 

 to include the manufacture of lime, hollow building blocks, tiles, 

 slabs, marbles, ornamental stones, etc. We are now investigat- 

 ing the available raw materials in the vicinity of Cebu, and 

 hope eventually to include the vicinities of Iloilo, Zamboanga, 

 and Jolo. 



66. Vitrified b7'ick. — We have made pressed and vitrified brick 

 from Philippine materials which have given very promising 

 results. The local manufacture of this product would be of 

 great financial importance. 



67. Quarries. — The city of Manila uses about 50,000 cubic 

 meters of crushed stone each year for surfacing streets. A 

 recent investigation of Laguna stone-quarries by a special com- 

 mittee which included a geologist of this Bureau has shown that 

 a much better rock could be secured and with an actual annual 

 saving of at least ?=21,000 to the city of Manila, besides a con- 

 siderable saving in maintenance. 



