Some signaling systems in metal-mine shafts.

Creator Personal:

Mosier, McHenry., Gleim, E. J. (Ernest J.)

Title:

Some signaling systems in metal-mine shafts.

Call Number:

P19470

Date:

1939

Description:

Serial issue. Issued as: United States. Bureau of Mines. Information circular, 7083 (1939:June).

Subject Topical:

Signals and signaling., Mine safety., Mine communication systems.