Om den här boken
Mitt bibliotek
Böcker på Google Play
OF THE
STATE
DEPARTMENT OF
MINING ENGINEERING,
THE PENNA. STATE COLLEGE.
9075
Table I-Comparison of the results from coal mine operations, 1892 and 1893...
Table II-New mines opened and old mines abandoned..........
Table III-Improvements at coal mines....
7
9
.12,
13
Table IV-Summary of the mines, employes, tonnage and value of output, by
counties.....
102-103: