Crane.| Prospecting, Mining and Milling Machinery. 233 
The coal bunkers or bins open directly into the boiler room, 
facing the boilers. 
CRUSHER Room.—The crusher room is usually built upon 
wooden columns or posts and stands from 8 to 10 up to 30 
and 40 feet above the jig room floor. The elevation of this 
room depends largely upon the location of the mill, whether 
on the level or on a slope, and is given such an elevation that 
gravity may act upon the material to be treated and aid in 
carrying it through the mill. The location of the feed shaft 
or shafts also has much to do with the position and height of 
the crusher room. 
_ Foundation columns of stone or concrete are placed every 
eight feet, upon which are erected, vertically, large timbers 
which support the rafters, to which are nailed the heavy oak 
floor planks. Upon the platform thus formed are erected the 
sides and roof of the crusher room, which protect the crusher 
feeders from the weather and serve as a temporary storage 
bin for the mine run ore. 
Tramways enter this room through large doors or openings 
in the sides or roof, while windows and doors are provided 
to furnish the necessary light and air. 
The floor in front of the crusher mouth is often sheathed 
with sheet, iron to prevent wear and to facilitate the handling 
of the dirt. On the mill side of the crusher room floor and 
projecting the width of the mouth in the room are placed one 
or more crushers. ‘The mouths of the crushers are on a level 
with the crusher room floor. 
ORE OR CONCENTRATES BINS AND STORAGE Room.—Strong 
bins are built, usually outdoors, and at one end of the jig 
room, either in front or to one side of the main door. The 
compartments in these bins, of which there are from four to 
eight, are usually 8x10, 10x10 or 10x12 feet, horizontal 
plan, and from 38% to 4 feet deep. They are strongly built, 
and braced by posts and plank. The corner as well as the 
side posts or supports are set in the ground, to which planks 
or floor timbers are fastened next to the ground. On these 
ground plank the bottom planks are nailed ; then the sides are 
boarded up and partitions placed dividing the main bin into 
compartments the size of which is given above. The tops of 
