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 190

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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 190

[page]190.[/page]

edge. Let AB and EF represent two adjacent cross sections of a shaft.

[image: two drawings of mine shafts and tunnels: first has parallel sides a and b connecting other parallel sides c and d then extending to A' and B'; second has parallel sides c and d connecting other parallel sides a and b then extending to connect side E'-F'.]
[caption]Figure 7.[/caption]

It will be seen that in one section the sides (a) and (b) pass the ends of the sides (c) and (d) while in the contiguous section the reverse is true. The curbing is built up of such sections alternating firmly united; thus preventing the caving of the sides of the shaft.
     After the shaft is completed the entries are begun. The entries are the streets and alleys of the mine and through them run the tramways. The entries are tunnels driven through the coal. The manner of driving them is by "shearing" and blasting, or by shearing mining and

Saving...

[page]190.[/page] edge. Let AB and EF represent two adjacent cross sections of a shaft. [image: two drawings of mine shafts and tunnels: first has parallel sides a and b connecting other parallel sides c and d then extending to A' and B'; second has parallel sides c and d connecting other parallel sides a and b then extending to connect side E'-F'.] [caption]Figure 7.[/caption] It will be seen that in one section the sides (a) and (b) pass the ends of the sides (c) and (d) while in the contiguous section the reverse is true. The curbing is built up of such sections alternating firmly united; thus preventing the caving of the sides of the shaft. After the shaft is completed the entries are begun. The entries are the streets and alleys of the mine and through them run the tramways. The entries are tunnels driven through the coal. The manner of driving them is by "shearing" and blasting, or by shearing mining and