SCIENCE 



[N. S. Vol. XXXIII. No. 836 



Iron, therefore, will never fail. It will 

 probably not change in its general relations 

 to modern conditions for a very long time 

 to come, so far as its ores are concerned. 

 We may have greater anxiety about the 

 supplies of coking coals than about the 

 iron ore, but there are always such possi- 

 bilities of improvements or changes in 

 processes that no one can justly give way 

 to unqualified forebodings. 



Copper is the metal generally considered 

 next in importance to iron. It is a very- 

 old one in the history of the race. The 

 bronze age, you will recall, preceded the 

 iron age. Prehistoric man in Europe 

 solved the mixed metallurgy of copper and 

 tin before he learned the smelting of iron. 

 Prehistoric man in America found native 

 copper on the shores of Lake Superior and 

 passed it in trade a thousand miles from 

 its home. As a cherished possession it con- 

 stituted his ornaments while he lived and it 

 was buried with him after he had died. 



Among the moderns, copper is most ex- 

 tensively employed in brass, but as a con- 

 ductor of electricity it finds year by year 

 increasing applications in the purest con- 

 dition in which the metallurgist can supply 

 it. If at home or in your office you look 

 around your chair or desk you will be sur- 

 prised to find how universally employed 

 it is. 



Greatly stimulated by tbe development 

 of electricity in later years the production 

 of copper has advanced by leaps and 

 bounds. At present the United States are 

 the heaviest producers, with Spain follow- 

 ing next, but only yielding one eighth as 

 much. The United States furnish over 

 half the total. In 1850 the United States 

 yielded 728 tons ; in 1900 over 303,000 and 

 in 1908, 471,000. Meantime in 1850 the 

 price of copper was about 30 cents per 

 pound. Its lowest point in recent years 

 was nine cents in 1894. Its highest, 25 



cents, was attained in 1907. We may each 

 of us imagine the variation in the profits 

 of a mining enterprise as between 11 cents 

 a pound and 15 cents, let alone 20 or 25 

 cents. Mining costs, smelting and freight 

 charges, show no such variation, so that 

 with rising prices profits greatly increase. 

 Indeed, few of the metals have such ex- 

 traordinary ups and downs as does copper. 



In its ores the yield varies greatly. On 

 Lake Superior, where the native metal is 

 distributed through ancient lava flows in 

 little pellets, leaves and sheets, it has been 

 profitably mined and produced through 

 periods of years, when it constituted but 

 three quarters of one per cent, of the ore. 

 The general run is, however, one per cent, 

 and above. If we recall that in a ton of 

 2,000 pounds one per cent, is 20 pounds, 

 and three quarters of one per cent. 15 

 pounds, and if copper is selling at, say, 13 

 cents, the mining manager must break 

 down, hoist, concentrate with attendant 

 losses, and smelt an ore worth less than two 

 dollars for all the metallic contents which 

 it contains. We can thus gain an idea of 

 the close and economical work required 

 and the ability demanded of a manager. 

 As the price rises the profits greatly in- 

 crease, and temporarily idle mines are 

 brought within the widening remunerative 

 zone, and are quickened into life. 

 As the price falls, the mines dangerously 

 near the line close down and production 

 ceases. The lowest cost of production 

 claimed is from the low grade and very 

 large ore bodies of the west and is placed 

 at or about eight to nine cents per pound 

 laid down in New York. 



In copper ores outside of the Lake Su- 

 perior region, we usually find the metal in 

 composition with sulphur. The ores as 

 they come from the mine may be rich 

 enough to go directly to the smelter, or 

 they may require concentration before the 



