Hawortu. | Historical. 15 
western country. Their principal interest lies in their isola- 
tion and historic associations. 
‘‘In the Mississippi valley the earliest report of the dis- 
covery of lead ore is that of Nicolos Perrot” in 1692, in Wis- 
consin, but this is of doubtful reliability. Certain it is, 
however, that LeSueur found the metal in both the lower and 
upper Mississippi areas in his expedition of 1701. 
‘«The development of the extensive Missouri deposits much 
preceded that of lowa and Wisconsin. It began about 1720, 
at Mine La Motte and other localities. It continued from 
then uninterruptedly to the present time, increasing almost 
constantly in magnitude, though there were a few periods of 
partial interruption. ‘The western Missouri ore bodies were 
hardly known before 1850, and they were not extensively 
opened until about 1870; since then their yield has increased 
enormously. 
‘‘In the upper Mississippi area, nothing seems to have 
been done until near the last decade of the eighteenth century. 
In 1766, John Carver found lead at Blue Mound. About 1788, 
Julian Dubuque began mining at Dubuque, and continued 
until 1810. After this, little was done until the occupation 
of the country by Americans in 1821. Then the development 
of lead mining over the whole upper Mississippi area became 
rapid, and the industry assumed large dimensions between 
the years 1840 and 1850. Since that time it has been com- 
paratively small. 
‘‘In southern Illinois the Massac and Hardin county de- 
posits were opened before 1821. The Rosiclare mine was 
discovered in 1839 and worked about 1842. Operations in 
the adjoining counties of Kentucky were principally between 
the years 1865 and 1875. 
‘‘In Kansas, Swallow” refers in 1866 to a little lead ore 
found in Miami and Linn counties. Attempts had been 
made to mine it before then. The only important deposits, 
in Cherokee county, were not discovered until 1876. 
‘In Arkansas, lead and zinc ores have been known for fifty 
years. Only desultory mining has been done. 
13. Irving, R. D., Ph. D.: The Mineral Resources of Wisconsin, p. 498. 
i 14. Swallow, G. C.: Preliminary Report of the Geological Survey of Kansas. Lawrence, 
66, p. 58. 
