418 
WISCONSIN STATE AGRICULTURAL SOCIETY. 
seat of action is too deep to be disturbed by the waters of the 
ocean, or to be reached by the arts of mining. 
Having now satisfied myself fully of the evidence of an ele¬ 
vation of land running north, and that this elevation was a 
line of physical disturbance along which the belts of mineral 
land in the lead district were arranged, I felt confident that 
the northern boundary of the lead district had not been reach¬ 
ed; hence I commenced a systematic investigation of the 
strata north of the last belt of mineral land in town six. 
Two important considerations led me to do this. 
(1.) It is usual for mineral districts formed like this, with 
east and west belts crossing a north and south axis, to taper 
out gradual^, that is the ranges become smaller, the ore- 
deposits scarcer or the ore more mixed up with other ma¬ 
terial. Having noticed instances of this kind before in well 
developed mineral districts, along well defined axes, and know¬ 
ing that these things are governed by general laws I looked 
with a great deal of confidence for a mineral belt of some kind 
north of the old boundaries of the lead district. (2.) The 
strata of the lead district crop out here, and if another belt is 
found it must be in the sandstone or below it. It is no easy 
matter, however, to discover a belt of mineral land where no 
excavations have been made. Those in the lead district were 
not noticed as belts until the present survey; and it is a ques¬ 
tion whether they would be noticed now, but for the mining 
excavations made along their course. 
In this my report on the region directly north of what was 
supposed to be the boundary line of the lead district, I will 
call attention to a class of phenomena somewhat different from 
that already described in the report of the lead district proper. 
The well defined belt of mineral land in town six (supposed 
to be the last belt of the lead district north,) is found along the 
southern flank and (in some instances) near the summit of an 
elevation or ridge of land running from near Prairie du Chien 
on the west to Blue Mounds on the east, a distance of sixty 
miles or more. This ridge of land, as before remarked, runs 
parallel with the belts of mineral land in the lead district, and 
