List of permissible mine equipment approved to January 1, 1940

Author:	Ilsley, L. C.
Year:	1940
Document Type:	USBI
Issuing Agency:	U.S. Dept. of the Interior, Bureau of Mines,
SUDOC:	I 28.27:7110
Series:	Information circular / Bureau of Mines ;
Report Number:	7110.
Subjects:	Coal mines and mining--Safety measures
	Explosives
Link:	https://hdl.handle.net/2027/mdp.39015078534792