250 APPENDIX. 



to reduce it ; which are both far greater than the lead-smelter 

 requires ; and, also, but for the scarcity of fuel. The cop- 

 per ore of this region compares very favorably with the 

 Cornwall copper ores. An analysis of a selected specimen 

 of the best working Cornwall ore, and of three average 

 specimens of Wisconsin ore, showed that the latter contains 

 from a fifteenth to a third more of copper than the former. 



" The Wisconsin ore is of a very uniform quality. There 

 was shipped from Ansley's ground, within a mile of Mineral 

 Point, in the year 1838, to England, 50,000 pounds of 

 ore ; which yielded (according to the statement of one of 

 the gentlemen who shipped it) over twenty per cent, of pure 

 copper. The average produce in the copper mines of Corn- 

 wall may be stated at eight per cent. 



" There have been raised, at the Mineral Point mines, 

 upward of a million and a half pounds of copper. At Ans- 

 ley's copper furnace, 135,000 pounds of this were smelted ; 

 which yielded, ' in a very imperfect smelting furnace,' 12,000 

 pounds pure copper, or about nine per cent. Mr. Ansley 

 stated that he had not been able to procure a smelter ac- 

 quainted with the mode of reducing copper ore ; and it is 

 impossible to say what the per centage might have been, had 

 the reduction been conducted with skill, and in a well-con- 

 structed furnace. 



" The Wisconsin copper veins may rank among the most 

 important that have yet been discovered in the limestone 

 formation. European copper mines in that geological group 

 (as in Staifordshire, England), usually yield very sparingly. 

 Cornwall, whicli is the greatest copper country in the world, 

 is composed entirely of crystalline, and the lower stratified 

 rocks, chiefly slate, associated with granite and porphyry. 

 The celebrated Pary's copper mine, in tlie island of Angle- 

 sea, occurs in a mountain composed of primary slate. 



