742 GEOLOGY AND TOPOGRAPHY OF THE LEAD REGION. 



Wasley Range. S. W. qr. of the S. E. qr. of Sec. 32, T. 5, R. 3 E. Course S. 85 

 E.; length, about 1,000 feet. 



Ballard Range. S. E. qr of the S. E. qr. of Sec. 32, T. 5, R. 3 E, Course N. 30 

 E.; length, about 800 feet. 



Besides these there are several small north and south ranges on the N. E. qr. of the 

 N. W. qr. of Sec. 5, T. 4, R. 3 E. 



Traces of copper ore are also found at many points north of Mineral Point, in the 

 diggings between that city and Dodgeville. 



A specimen of ore containing a considerable carbonate of copper was presented by 

 Hon. H. H. Gray, of Dodgeville. It was found about fifteen feet from the surface, on 

 the S. W. qr. of Sec. 22, T. 2, R. 3 E. 



Specimens of sulphuret of copper were obtained from some old diggings on the S. 

 W. qr. of Sec. 8, T. 1, R. 5 E. The course of this range is about S. 20 E. Copper 

 was mined here as early as 1838, and two or three loads of ore were brought to Mine- 

 ral Point for reduction. A specimen from this locality afforded 10.86 per cent, of metal- 

 lic copper. 



STATISTICS OF ZINC OKE. 



The statistics of the production of zinc ores are believed to be complete, and to em- 

 brace the annual production from the year 1860 (at which time the zinc ores began to 

 be utilized) to October, 1876. The ore is all consumed at La Salle, 111., by four com- 

 panies. By far the greatest quantity of the ore is shipped from Mineral Point; the other 

 points are Platteville, Council Hill, and Galena. 



The blende is shipped in its crude state, as it comes from the mines; but the carbo- 

 nate of zinc (drybone) is previously roasted or calcined, by which process it loses its 

 carbonic acid, which constitutes about one-third of its weight, and is decreased in bulk 

 in the same ratio. The small amount of water, which is usually present as a mechani- 

 cal mixture with the ore, is also driven off. 



The ore is calcined in a small and inexpensive furnace, resembling a lime-kiln in its 

 structure and object, capable of containing about sixty tons of raw ore. Such a furnace 

 will roast about twenty-five tons of ore in twenty-four hours, and requires the labor of 

 six men at eight hours apiece (three shifts). From eighty to one hundred pounds of 

 bituminous coal are required for each ton of ore. 



The cost of carrying the ore through this operation is from fifty to sixty cents per ton. 

 The coet of a furnace and requisite tools is about $300. 



The following are the amounts of zinc ores produced in the lead region from 1860 to 

 October 1, 1876. The table has been prepared from the books of the four manufacturing 

 companies, to whom I am greatly indebted for their ready cooperation and assistance: 



Smithtonite, Blende, 



Year. Ibs. Ibs. 



1860 320,000 



1861 266>000 



1862 



1863 1,120,000 



1884 3,173,333 



1865 4,198,200 



1866 7,373,333 



1867 5,181,445 841,310 



1868 4,302.383 3,078-,4.T5 



1869 4,547,971 6,252,420 



