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 197

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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 197

[page]197.[/page]

up by posts of wood called props. The roof in the entries is kept up by timbering. The system of timbering is [?merly?] timbers placed across the entry under the roof and held up in some manner at each end. Figues 10, 11, and 12 show these methods of timbering entries. 

[image: wood beam sits across the entry's widened top]
[caption]Figure 10[/caption]

[image: wood beam propped by end wood parts sits across the entry's widened top]
[caption]Figure 11[/caption]

[image: entry is framed by wood columns on small wood bases that hold up wood beam at ceiling]
[caption]Figure 12[/caption]

That shown in figure 10 is adapted to entries in which the wall are of firm material. The method shown in figure 11 is used in case of weak walls whill [?which?] will sustain the pressure when not applied too near the edge. The third method (Fig. 12) is the surest method but at the same time the most expensive. The expense comes in both in both in [???]

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[page]197.[/page] up by posts of wood called props. The roof in the entries is kept up by timbering. The system of timbering is [?merly?] timbers placed across the entry under the roof and held up in some manner at each end. Figues 10, 11, and 12 show these methods of timbering entries. [image: wood beam sits across the entry's widened top] [caption]Figure 10[/caption] [image: wood beam propped by end wood parts sits across the entry's widened top] [caption]Figure 11[/caption] [image: entry is framed by wood columns on small wood bases that hold up wood beam at ceiling] [caption]Figure 12[/caption] That shown in figure 10 is adapted to entries in which the wall are of firm material. The method shown in figure 11 is used in case of weak walls whill [?which?] will sustain the pressure when not applied too near the edge. The third method (Fig. 12) is the surest method but at the same time the most expensive. The expense comes in both in both in [???]