GEOLOGY. 269 



Production of Copper. The Lake Superior Mining Journal gives 

 the following information respecting the production of copper : 



" In 1830, the total productions of the copper mines of the world 

 was about 25,500 tons of metal, and of this amount Great Britain 

 produced 13,200, or more than fifty per cent, of the whole, while the 

 United States and Canada furnished but fifty tons, or two-tenths of 

 one per cent. The Russian Empire then produced nearly 4,000 tons; 

 the Austrian Empire 2,150 tons; the whole of Asia some 2,500 tons. 

 In 1853, twenty-three years later, Britain had only increased her annual 

 product to 14,500 tons, her percentage of the whole amount receding 

 to twenty-six; while Chili, in South America, which in 1830 only 

 yielded 200 tons, had raised her product to 14,000 tons, or over 

 twenty-five per cent, of the total production. From that period for- 

 ward to the present time, the copper production of the Chilian mines, 

 we believe, exceeded those of any other country ; the value of their 

 exports in that metal alone amounting to $10,760,000 in 1857, while 

 the value of British mine products for the same year was worth about 

 $9,500,000. The Russians had increased the yield of their mines to 

 6,500, or eleven and three-fourths per cent, of the whole; the Aus- 

 trians 3,300 tons, or six per cent.; the whole of Asia only 3,000 tons, 

 or five and one-half per cent. ; while the United States and Canadas 

 raised that year 2,000 tons, or over three and one-half per cent, of 

 the total products for that year, which were about 55,700 tons ; Aus- 

 tralia and New Zealand produced about 3,000 tons; Cuba, 350 tons; 

 Scandinavia, 2,000 tons-, the German States, 1,450 tons; and the rest 

 of Europe, exclusive t of the countries above named, 1,000 tons. 

 During the past ten years the mines of Lake Superior have probably 

 increased their production more rapidly than those of any other 

 country, the exports for 1861 7,500 tons of metal being about 

 twelve times greater than those of 1851." 



Texture of Copper. M. Vivian, of France, some time ago showed 

 that manufactured copper always has a porous and cellular texture, 

 whilst native copper is always crystalline. Now he proves that the 

 native copper from Lake Superior is neither crystalline nor cellular, 

 but dense, ductile, and fibrous, as though it had been violently com- 

 pressed when cold. When melted it however takes the structure of 

 all manufactured copper. Cosmos. 



Immense Mass of Copper. During the past year another immense 

 mass of metallic copper has been discovered in the Lake Superior 

 district, in the vicinity of the so-called Mesnard Mine. Little of the 

 mass was above the surface when discovered, and that little was so 

 covered by moss and small underbrush as to hardly attract attention. 

 Upon being uncovered, and the soil removed from around its sides, 

 traces of Indian workings were found, pieces of charcoal, and half a 

 dozen stone hammers, were taken out; and the eastern end of the 

 mass shows plainly that a portion has been broken off. The average 

 dimensions, says the Lake Superior Mining Journal, are, - - length, 

 fifteen feet seven inches ; width, three feet seven inches (it is full 

 five feet in one place) ; thickness, one foot six inches ; giving 87,135 

 cubic feet. All these measurements are rather under than over the 

 average, and give a weight to the mass of nearly twenty-seven ton-. 



The immense weight of this boulder of copper naturally 

 23* * 



