258 ^^6 Philippine Journal of Science lau 



the hematite and magnetite ore at Mambulao Bay, Camarines. 

 This condition may defer operations on a larger scale in Bulacan. 



Because of their location, it is probably not practicable to 

 erect a reduction plant at the site of any of the ore deposits. If 

 the plant cannot be located at the ore deposits, its situation will 

 be determined by the market and electrical power factors. The 

 possibilities of long-distance transmission of electric current 

 leaves the manufacturing site independent within certain limits 

 of the power-plant site. Market requirements will best be met 

 if the plant is established at Manila itself, although some ad- 

 vantage in shorter transportation of ore, flux, and charcoal would 

 be gained and the market would still be close at hand if a site 

 at the head of navigation on Angat River were selected. 



Aerial cableways offer the best solution of the problem of 

 getting the ore down out of the mountains. By providing suit- 

 able intermediate loading stations, charcoal and limestone flux 

 could be brought down on the ore cableway. The cableway might 

 possibly be extended to a point where water transportation was 

 available; if any intermediate haul were necessary, it would be 

 short and through level country. So far as can be ascertained 

 in advance of exploration, the largest supply of ore is at Ca- 

 maching, but intelligent prospecting by diamond-drill methods, 

 which should precede actual development, might reveal larger 

 ore reserves elsewhere. With suitable branch cableways, ore 

 would be taken from several of the deposits at the same time. 



The vicinity of Polo a short distance above Matictic, on Angat 

 River, has been proposed as a tentative site for hydroelectric 

 development by Col. C. de las Heras, an engineer in the Spanish 

 army who was formerly in charge of water supply for the city 

 of Manila. Practically the same site is contemplated in preli- 

 minary plans by the Bureau of Public Works for the develop- 

 ment of electricity in connection with an irrigation project 

 which would secure water from Angat River. The irrigation 

 division of the Bureau of Public Works maintained a gauging 

 station at Polo throughout the years 1910 and 1911. Their 

 records show a minimum flow of 7,000 and a maximum flow 

 of 1,198,000 second liters of water in Angat River at this point 

 during the period covered by their observations. Colonel Heras's 

 estimates show that at ordinary stages of the river 5,800 kilo- 

 watts, and at the lowest stage a minimum of 3,700 kilowatts of 

 electrical power, could be generated if a suitable dam were 

 constructed across Angat River, a short distance above Polo. 



