KEMP, GEOLOGY AXD ECOXOillCS 373 



annum. For a life of twenty years, a time practically demanded of 

 such an enterprise to justify the great expense of installation, at least 

 12,000,000 tons must be shown by the drill before the enterprise can 

 safely begin. If we expect to mine three times this amount per day, we 

 call for three times as much ore. These figures, large as they may seem, 

 are not bevond the estimates of ore bodies as now blocked out in several 

 places in the West, and even with these great demands, twenty years' sup- 

 ply and even more in instances have been demonstrated. 



Let us now imagine again a 2,000-ton daily output of say 2.25 per cent, 

 ore, of which the mill saves two thirds, or 30 pounds of copper in the ton. 

 The output in copper per day will be 60,000 poimds, or 30 tons, and for 

 the year 9,000 tons. Should three new companies start up with four or 

 five times this output, 3G,000 to 45,000 tons will be added to a yearly 

 supply, which in 1909 was 552,668 tons. "We see great need of a growing 

 demand in order that these vast contributions may be absorbed. Yet 1 

 have made no unreasonable assumptions nor have I overstepped the prac- 

 tical certainties of the next few years. 



How long will our copper hold out ? Mines come and go, and for the 

 immediate future there will certainly be no scarcity. Copper does not 

 oxidize as readily as iron and is not lost. The world's stock steadily 

 accumulates. But twenty years is not a long look ahead. Are there new 

 countries which will be producers ? Some of the old mines in Europe are 

 now no longer great sources of the metal. 



We do know of possibilities in Alaska that will add some contributions. 

 We know of new or recently opened ore bodies in Peru, Bolivia and Chile 

 that promise well. We hear of very large deposits in the southeastern 

 corner of the Congo State, once worked by the ancients, now revived by 

 the moderns and possessing large reserves of 15 per cent, copper ore. 

 The Cape to Cairo railway will give them great impetus. For the inmie- 

 diate future, there is no lack, but if we look fifty years or a century ahead, 

 we can speak with less confidence. In a general way, we may say that 

 probably new discoveries will, for a time at least, more than keep pace 

 with demands. But when we look fifty vears into the future we are not 

 so certain. It behooves the producers to use no treatment of an ore ex- 

 cept a careful and economical one. If tailings and waste from our mills 

 now contain one third the copper in the original ore. they should be im- 

 pounded and kept from being washed away by floods, against the possible 

 call of the future. We dare not say that they will never be within the 

 ranges of profitable treatment even though their low percentage places 

 the copper beyond reach to-day. The copper situation is not one to ex- 

 cite anxiety, yet it is also one not to encourage extravagance. 



