366 University Geological Survey of Kansas. 
unbound rock and ore on either side of the cutting is then 
blasted in the opening thus formed, and the operation of cut- 
ting and knocking down is continued until the bounds of the 
deposit are reached. A plan of a section of a working face, 
showing cuttings and arrangement of holes for knocking 
down the ore, is shown in figure 15. 
LINE ” 
AESOP 2 9 
Thy 
A ‘ 
ie ' 
Laisa 
Z (Ze 
SIAIA 
Ss or 
SAM les me c 
B ' 
; 0% 
Ya ’ ' 7 0 
1 ’ 
AN\ 1 ‘ \ wos 
—— i] ’ 
SS =\ i, 
GY S =< s Ew 
Zail\S NN WHE - ge See hes 
7) “e. ' n 
WALL X Uy ‘ , in, 
SY ' 0 9 
‘ i] i ' 
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Sa ' 1 
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Ny BAX ly FACE 
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WSS 
Fig. 15. Method of working sheet ground. 
Treatment of Ores. 
Mine run ore is now being screened in many cases and the 
sizes thus produced are sent directly to the apparatus in- 
tended to handle them. ‘The reducing and sizing apparatus 
are by this means relieved of large quantities of material 
either too large or too small for them to handle conveniently. 
In a similar manner certain of the concentrating apparatus 
are relieved of an extra burden of mineral which crowds 
them and renders good separation impossible. Such an ar- 
rangement regulates the feed to the jigs and other concen- 
trating apparatus. 7 
StimME TREATMENT.*—The employment of a systematic 
* Excerpt from an article in the Eng. and Min. Journal, Apr. 28, 1904, p. 688, by W. R. Crane. 
