i 
38 Wisconsin and Missouri Lead Region. 
between the strata. But in all cases on reaching the sandstone, 
they are, as far as is yet known, unproductive. They are fol- 
lowed when they are found to yield three inches of galena, that 
being the least vein it is thought worth while to pursue through 
rock ; and it is very rare indeed that a continuous vein is found 
exceeding one foot in thickness. The horizontal direction of the 
fissures is more uniform; those producing the most ore almost 
universally running nearly east and west. Near Mineral Point, 
some fissures running north and south produce good ore, but they 
are for the most part horizontal beds (of limited width) between 
the strata, and out of these directions it is rare to find a produc- 
tive fissure. The smelters think they can distinguish the ores 
that are found in different fissures—that from an east and west 
fissure being perfectly crystallized, of a smooth surface, striz in- 
distinct ; that from a north and south fissure, of crystalline struc- 
ture, with two sets of striz very distinct, crossing each other at 
right angles; and the ore froma quartering fissure crystalline, 
with many sets of striz# crossing each other obliquely ; and to 
some extent I had opportunity of proving their observations cor- 
rect. The fissures appear to be limited in length to within a 
few hundred feet, and to lie in ranges which extend at right an- 
gles with the direction of the fissures. In the neighborhood of 
Mineral Point many of these fissures are opened and mined, and 
the “diggings” are seen to extend with little ieregularity i ina 
north and south belt, that part to the west producing lead ore; 
half a mile to the east the fissures containing copper ore, and still 
further east a mile or more, hematite iron ore abounds in them. , 
The deepest shafts that have been sunk on these fissures are 
about ninety feet ; and at Mineral Point they may be worked to 
that depth without the water being troublesome. But as these 
deep shafts were sunk on the highest ground, the bottom of them 
hardly reaches the sandstone. 
Jopper Ores.—T he copper ore is similarly situated to the lead 
ores, either in wide fissures or in thin veins running through the 
rock. As many as four of the little veins not exceeding two 
inches in thickness have been found running about east and west 
on different parts of the mining ground. The ore in these is a 
mixture of the sulphuret and carbonate. Besides these, which 
are not considered important, there is a large fissure, in places 
fourteen feet wide , that has been traced bank a siete ofa tile. , 
