Inside Out Library
Scientific American, Vol. 87, No. 16 (1902) (1902)
leaf 7
d, initial drop into the track hopper there is no further attempt was made to reload by gravity, all the coal is supplemented by reloading conveyors piaced either drop exceeding a few inches. being reloaded by hand. Later there was introduced in the tunnels or against the faces of the retaining The… … © 1902 SCIENTIFIC AMERICAN, INC.Internet Archive · Public domain (published before 1931). Free to use for anything.
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