Guarding trolley wires in mines

Author:	Gleim, E. J.
Year:	1932
Document Type:	USBI
Issuing Agency:	U.S. Dept. of Commerce, Bureau of Mines,
SUDOC:	C 22.11:6577
Series:	Information circular / United States Department of Commerce, Bureau of Mines ;
Report Number:	6577
Subjects:	Mine safety
	Electricity in mining
Link:	https://hdl.handle.net/2027/mdp.39015086485177