Safety electric switches for mines

Author:	Clark, H. H.
Year:	1913
Document Type:	USBM
Issuing Agency:	U.S. Dept. of the Interior, Bureau of Mines,
SUDOC:	I 28.7:44
Series:	Technical paper / United States Department of the Interior, Bureau of Mines ;
Report Number:	44
Subjects:	Electricity in mining
	Electric switchgear
Link:	https://hdl.handle.net/2027/mdp.39015077561002