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Miscellaneous mining methods 81
Block system of mining 81
Attempt to reopen Hillman bed 82
Buggy-road mining 84
Room-and-pillar mining in thin beds 88
Mining under Susquehanna Biver at Seneca colliery 89
Influx of water 90
Conservation of small areas of anthracite 91
Summary of mining methods 96
Mining adjacent beds 96
Longwall and semilongwall mining 97
Scraper mining . 97
Shaking chutes 98
Silting 99
Miscellaneous mining methods 100
Mechanical mining 101
Conclusions . 103
Introduction of new mining methods 103
Advantages of longwall and semilongwall mining 104
Saving possible 104
Source of material for silting 105
Use of mechanical devices 106
Mechanical loading of coal 108
Mining methods for Northern field 109
ILLUSTRATIONS
Kg.
1. Correlation and nomenclature of coal beds in the Northern field of
the Pennsylvania anthracite region 6
2. Correlation and nomenclature of coal beds in the Eastern Middle,
Western Middle, and Southern fields of the Pennsylvania anthra-
cite region 8
3. Correlation of anthracite beds in the Northern field, by districts,
showing average elevation of surface, average maximum depth of
beds, average interval between beds, average thickness of beds, and
relationship to nomenclature suggested by the Second Geological
Survey of Pennsylvania 10
4. Correlation of anthracite beds in the Eastern Middle, Western Middle,
and Southern fields, by districts, showing average elevation of sur-
face, average maximum depth of beds, average interval between
beds, average thickness of beds, and relationship to nomenclature
suggested by the Second Geological Survey of Pennsylvania 10
5. Map of No. 3 Dunmore bed at Forest City colliery 12
. 6. Sketch showing method of handling dividing rock at Forest City
colliery and at Hillside Coal & Iron Co. colliery 14
7. Map of No. 2 and No. 3 Dunmore beds, showing method of working 15
8. Map of No. 2 Dunmore bed 16
9. Map of Lower Diamond and Bock beds at Archbald colliery of Glen
Alden Coal Co., showing columnization 20
10. Map of Twin beds at Nanticoke No. 5 colliery, Susquehanna Collieries