 | Great Britain. General Board of Health - 1858 - 224 páginas
...through the roof of the mine, whilst the sandstone strata, which are impervious to warer, preserve the mine quite dry ; consequently, the minute particles...dust, which the miner is constantly inhaling."—" The effects of Arts, Trades, and Professions as affecting Health and Longevity," by C. Turner Thackrah,... | |
 | Institution of Mining and Metallurgy (Great Britain) - 1904 - 816 páginas
...through the roof of the mine ; whilst the sandstone strata, which are impervious to water, preserve the mine quite dry ; consequently the minute particles...on the contrary, are laid as they are formed by the constant oozing, dropping and splashing of the insinuating water '. He states that the conditions were... | |
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The explanation of the harmful nature of sandstone as compared with limestone is, "that the latter is full of vertical and other fissures, which allow the superincumbent beds of water to percolate through the roof of the mine; whilst the sandstone strata,... 