DIY History | Transcribe | Scholarship at Iowa | Coal Measures and Coal Mining in Iowa, including paleontology and a discussion on the coal formation; also the methods of mining by Russell T. Hartman, 1898 | Coal Measures and Coal Mining in Iowa by Russell T. Hartman, 1898, Page 189

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Coal Measures and Coal Mining in Iowa, including paleontology and a discussion on the coal formation; also the methods of mining by Russell T. Hartman, 1898

Coal Measures and Coal Mining in Iowa by Russell T. Hartman, 1898, Page 189

[page]189.[/page]

partments and by opening one compartment at a time allowing the floor to sink.
     There is always more or less rock to go through in sinking a shaft. This is penetrated by blasting or "shovling". First a hole A is drilled in the center of the shaft (See Fig. 6.). 

[image: drawing of a vertical entry to coal face with 3 vertical holes with the first middle hole widened to a conical shape; labels A, B, B]
[caption]Fig. 6.[/caption]

A charge of some explosive is placed in this hole and fired; this leaves a roughly conical hole shown by the dotted lines. Other holes B B are then drilled and charges are fired in them throwing the debris into the center. The loose rock is then taken out and the operation repeated.
     In curbing or timbering a shaft planks are usually used being laid flatwise instead of on

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[page]189.[/page] partments and by opening one compartment at a time allowing the floor to sink. There is always more or less rock to go through in sinking a shaft. This is penetrated by blasting or "shovling". First a hole A is drilled in the center of the shaft (See Fig. 6.). [image: drawing of a vertical entry to coal face with 3 vertical holes with the first middle hole widened to a conical shape; labels A, B, B] [caption]Fig. 6.[/caption] A charge of some explosive is placed in this hole and fired; this leaves a roughly conical hole shown by the dotted lines. Other holes B B are then drilled and charges are fired in them throwing the debris into the center. The loose rock is then taken out and the operation repeated. In curbing or timbering a shaft planks are usually used being laid flatwise instead of on