ANNUAL REPORT FOR 1873. 27 



add very materially to our knowledge of the minute topography of 

 the state. They will also soon become still more valuable as a means 

 of showing what changes are annually taking place along the course of 

 these important rivers. 



With the public land surveys, thus tested and corrected, together 

 with the railroad surveys, and the barometrical measurements of 

 heights by the geological survey, we shall have abundant material for 

 the construction of a very full and correct topograpical map of the 

 state. 



It is therefore to be hoped that means will not be withheld for the 

 vigorous prosecution of these important surveys on the part of the 

 United States government. All such work is of the greatest practi- 

 cal importance in the more correct determination of the boundaries 

 of real estate, thus, perhaps, preventing future litigation, neighbor- 

 hood quarrels, and uncertainty as to the ownership of property. 



MINERALS. The following enumeration of the mineral species 

 heretofore found in Wisconsin, has been made up from observation, 

 and from various sources of information ; and though it is, doubtless, 

 far from complete, either in the number of species existing in the 

 state, or in the enumeration of localities, it will serve as a beginning 

 towards the more complete mineralogical survey contemplated. 



CATALOGUE OF MINERALS. 1 

 I. NATIVE ELEMENTS. 



Gold. Gold is said to have been found in several places in the northern part of the state. 



Silver. Native silver is found associated with copper in boulders of the drift, having 

 been transported from the copper veins of Lake Superior. It is said to occur in veina 

 on the Montreal river; and, associated with lead, in Ashland county. 



Copper. Copper has been found in limited quantities in regular veins on the Montreal 

 river and at several other places in Ashland and Douglas counties. In the form o 

 drift boulders it is often found, especially in the eastern half of the state; the masses 

 vary from a few ounces to several hundred pounds; the largest, found near Hustis- 

 ford in Dodge county, had a weight of 487 pounds. 



Iron, Meteoric iron has been found in Washington county on the farm of Louis Korb, 

 in masses varying from 8 to 62 pounds. They are, apparently, all fragments of one 

 meteorite which must have exploded when very near the surface of the ground. It 

 has been analyzed and described, and samples sent to collectors under the name of 

 the " "Wisconsin Meteorite." The presence of nickel, and peculiar Widmannstathiazi 

 figures leave no doubt of the meteoric origin of tin's iron. 



Native Sulphur. Sulphur, resulting from the decomposition of marcasite, has been 

 found in the lead mines at Mineral Point, Shullsburg, etc. 



Graphite (Plumbago, Black Lead). Graphite is said to have been found in the northern 

 portion of the state. 



i A list of all the minerals known at the close o/the survey to occur in the state will be given ia 

 another volume of the report. 



