LEAD AND ZINC DEPOSITS, ETC. 613 



rations have revealed new fields, or improvements in mining and 

 metallurgical methods have made previously rejected ores avail- 

 able. Along with this, the utilization of the associated zinc ores 

 has led to the opening up of deposits which previously lay 

 untouched, enclosing often unexpected quantities of lead. Dur- 

 ing the past twenty years Missouri's production has reached large 

 proportions. The total amount mined during this period is fully 

 twice that of the preceding 1 50 years — a startling refutation of the 

 early adverse predictions. The output during recent years has 

 been only second to Colorado's, and this year will probably 

 be first among the states of the Union ; the total amount pro- 

 duced to date probably equals, if it does not exceed, that of any 

 other state. 



Similar in some respects are the facts of zinc production. The 

 miningof these ores does not, however, datemuch more than twenty 

 years back, and hence the industry has not suffered much from 

 the vicissitudes of the early mining. The production grew rap- 

 idly from its beginning, and now ranks first in the country. The 

 total output up to the present time is nearly equal to the combined 

 total productions to date of all other states in the Union. 



The showing for the Upper Mississippi or Wisconsin zinc and 

 lead area is not quite so good. Mining there dates hardly more 

 than 100 years back, and it was not on an active basis before 

 1823. The period of maximum work was about the year 1845, 

 and soon after this time Prof. Whitney seems to have been of 

 the opinion that its prospects were better than Missouri's, though 

 he predicted a continued decline. The utilization of the zinc 

 ores began about i860, which tended to sustain the mining indus- 

 try and the production of lead, though on a much reduced scale. 

 In the early seventies the production of zinc was quite large and 

 something like a resuscitation of mining took place. During the 

 past thirteen years there has, however, been a general decline, and 

 recently little mining has been in progress. At the time of 

 maximum activity, in 1845, the production of lead was about 

 27,000 tons per annum; but that of zinc ore, in 1872, was only 

 22,000 tons. The total amount of lead produced to date is prob- 



