234 University Geological Survey of Kansas. 
the posts are further strengthened by plank 2x4 or 2x6, nailed 
down flatwise, thus forming a railing around the top, which 
is used as a walk. 
A plank extending from the jig room door furnishes a track 
for wheelbarrows, in which the concentrates are transferred 
from the jig room to the bin. 
When the concentrates are hauled by cars the track is built 
directly over the middle or to one side of the bin. In the 
latter case there are usually two lines of track, which extend 
in a straight line through the jig room, and thence to the bin, 
and are provided with switches at several points. The cars 
are run by hand from the front of the jigs out to the bin, 
where they are dumped and run back again. These cars are 
so arranged that they are readily handled and dumped. — 
The storage room is generally situated under the crusher 
room, in the vacant space between the columns or posts sup- 
porting the floor of the same. It is used for storing oil, 
cables, roll shells, and repairs of all kinds. 
The method of handling and storing the mine run ore is 
gradually changing the plan of construction of the mill 
buildings. Formerly the only place for storage was in the 
crusher-room, but, beyond a certain tonnage, it was found 
that the crusher feeders were interfered with, due to accumu- 
lation of ore. ‘This led to an increase in the height of the 
mill building, with the addition of ore bins—usually two— 
which are filled with sized products from grizzlies situated at 
the top of the same. Probably the best illustration of this 
construction can be borrowed from mills located in Chitwood 
Hollow, Mo., one of the most typical of which is the Lack- 
awanna mill. 
This method of construction tends toward the multiple 
story style, or the so-called gravity mills, in which the 
rougher jigs occupy the second floor, while the finishers or 
cleaner jigs complete the concentration below. 
Crusher Frame. 
The crusher, although situated in the jig room, must stand 
on a level with the floor of the crusher room. The mouth or 
feed of the crusher extends into the crusher room and is on a 
