The copper interest of Michigan was first brought into public notice by the enormous speculations and the mad fever of 1845. The large spur of country which projects far out into the lake, having its base resting on a line drawn across from L'Anse Bay to Ontonagon, and the Porcupine Mountains for its spine, became the El Dorado of all copperdom of that day. In this year the first active operations were commenced at the Cliff Mine, just back of Eagle River harbor. Three years later, in 1848, work was undertaken at the Minnesota, some fifteen miles back from the lake at Ontonagon. The history of the copper mines on Lake Superior shows that even the best mines disappointed the owners in the beginning. We give the facts relative to the three mines at present in the Lake Superior region to illustrate this. The Cliff Mine was discovered in 1845, and worked three years without much sign of success; it changed hands at the very moment when the vein was opened which proved afterward to be so exceedingly rich in copper and silver, producing now on an average 1,500 tons of stamp, barrel, and mass copper per annum. The Minnesota Mine was discovered in 1848, and for the first three years gave no very encouraging results. The first large mass of native copper of about seven tons was found in a pit made by an ancient race. After that discovery much money was spent before any other further indications of copper were found. This mine yields now about 2,000 tons of copper per annum, and declared, for the year 1858, a net dividend of $300,000. The dividends paid since 1852 amount to upward of $1,500,000 on a paid-up capital of $66,000. The same has been experienced at the Pewabic Mine. That mine commenced operations in the year 1855, with an expenditure of $26,357, which produced $1,080 worth of copper; the second year it expended $40,820, and produced $31,492 of copper; in 1857 $24,484 of expenses produced $44,058 worth of copper; 1858, the amount expended was $109,152, and the receipts for copper $76,538; the total expense amounts to $235,816, and the total receipts for copper to $153,168, leaving an excess of expenses amounting to $82,648, which is, however, amply covered by the extensive works established above and below ground at the mine. The Pewabic will undoubtedly take its place among the dividend-paying mines of the present year.