474 
WISCONSIN STATE AGRICULTURAL SOCIETY. 
in the lower strata, I do not, therefore, claim that they must 
necessarily be so. All I assert is, that there is no reason why 
they may not be. And this is all that can be said of unex¬ 
plored mineral strata anywhere, under any circumstances. 
But whether these fissures will extend into the sandstone and 
magnesian limestone, and become productive or not, is still an 
unsettled question, one that can be determined only by a 
regular process of mining. 
But one thing is now settled which was thought to be 
doubtful some years ago, and that is; these fissures are now 
known to traverse alike the different beds of the strata 
above the sandstone and that they are sometimes productive 
in one, sometimes in another, sometimes in all, in the same 
mine. A great many examples of this can be furnished in 
mines that are now open. The Linden mines already referred 
to, and the Crow Branch mines, in Grant county, are good ex¬ 
amples. In the latter, a rich deposit has been, and is now, being- 
worked in the blue limestone. Where the mine is worked 
back into the hill to the east of the valley, there is from 80 to 
100 feet of galena limestone, through which the fissures de¬ 
scend from the surface with but little indications of mineral 
until within a few feet of the blue limestone ; but here the ore 
commences and extends through the different belts of the blue 
limestone to where the sandstone should be, as exposed to the 
south of the mine. This deposit, in connection with these fis¬ 
sures that can be traced through a large portion of the galena 
limestone (or the whole of that formation that is present there) 
and through the entire blue limestone, has yielded not less than 
six, perhaps seven million pounds of lead ore, besides a vast 
amount of zinc. 
Now, a glance at my map will show that there is a large 
portion of the mineral formation in the lead district into which 
these fissures are known to extend, and in which they are 
known to be productive, that is yet untouched above the sand¬ 
stone. Certainly not one mine in twenty, on an average, along 
the belts of mineral land has reached the blue limestone; not 
one in a hundred, along the two southern belts; and yet the 
