COPPER. Very little copper was mined prior to the development of the Lake Superior copper mines, which began operations in 1845. From that year the product has continued to increase steadily and rapidly. In 1866 the famous Calu met and Hecla mine was opened, and in 1800 its annual product had grown to 59,868,106 pounds, and in 1001 to 82,519,676 pounds. In 1880 Lake Superior ores furnished 822 per cent. of the total product of the country. About this time Arizona began to figure prominently in copper mining, and a little later Montana also, the latter advancing so rapidly that in 1885 it pro duced 40.9 per cent. of the total product, as against 43.5 for Lake Superior and 13.7 for Arizona. Though the Lake Superior output con tinued to increase, its per cent. of the total had fallen to 25.9 in 1901. Montana more than doubled its output in the decade ending 1901, producing in that year 38.2 per cent. of the total product, while Arizona increased its output three and one-half times in the same period, having 21.7 per cent. of the total product in 1901.
In the last years of that decade California and Utah rapidly advanced in their output of copper. The principal Montana mines are located at Butte, the largest mining centre in the world. The Anaconda mine produced, in 1901, 101,850, 224 pounds, and the Boston and Montana nearly half that amount. In Arizona the Copper Queen yielded 39,781,133 pounds, and the United Verde 34,520.605 pounds. The total output for the United States increased from 27,000 long tons in 1880 to 115,966 iu 1890, and 268,782 long tons in 1901, these amounts being respectively 17 per cent., 43 per cent., and 53 per cent. of the world's product. The value of the output in 1901 was $86,6;29,266. The United States is now the controlling factor in the world's copper markets.