CRANE. | Developing Mineral Properties. 201 
mine by additions from below. If the ore body widens out 
as it dips downward, the mine both broadens and heightens. 
Some worked-out portions of a mine may by this broadening 
and heightening process assume stupendous proportions, yet 
are perfectly safe, if proper precautions are taken from day 
to day as the process of enlargement advances. 
The actual process of stoping is as follows: As the upper 
part of the portion to be stoped, called the ‘‘bench,’’ is un- 
bound, or freed, all that is necessary to be done is to break 
up the floor of the drift by shots properly placed. One or 
two heavy charges of powder will readily heave the seven to 
ten feet of free rock the full width of the drift, so that as fast 
as the debris is cleared away and the holes drilled the process 
can be repeated. D, figure 16. 
It is thus evident that drilling and blasting constitute 
quite a large and important part of the mining operations. In 
a fairly rich mine, where nearly all the material is pay dirt, 
most of the processes of drifting and stoping are employed in 
extracting the ore, all dirt obtained being mill dirt. The 
ground foreman then plans so to work the ground that the 
loosened rock will under the action of gravity fall and roll 
toward the shaft or as near to it as possible and convenient. 
To accomplish this the floor of a drift is generally stoped up 
to a depth of from eighteen to thirty feet, and nearly to the 
end of the drift. The remaining portion or bench serves 
as a platform, or aids in supporting a scaffolding upon which 
the men stand while working the face of the drift and stoping 
the face and upper portions of the bench. Plates XXX V 
aud XXXVI. The material loosened falls down the face of 
the stope, which with the bench make a long incline, ex- 
tending, if possible, in the direction of the foot of the shaft. 
Any ore thrown on this slope will with very little labor 
be brought to the foot of the same, at which point is placed a 
platform of plank, formed by placing 2x 12 inch planks side 
by side. The ore continually sliding down the incline or slope 
partly covers these planks, binding them down, thus forming 
a smooth floor, upon which the ‘‘cockey’’ or spade hand 
stands and shovels into the cars or buckets on trucks, which 
run from the foot of the shaft to the platform upon a narrow 
