Automatic power releases for shutting off power from mine and indicating by signal alarm when fan stops or doors are left open

Author:	Fene, W. J.
Year:	1930
Document Type:	MAIN
Issuing Agency:	U.S. Dept. of Commerce, Bureau of Mines,
SUDOC:	C 22.11:6288
Series:	Information circular ;
Report Number:	6288
Subjects:	Mine ventilation
	Mine safety
Link:	https://hdl.handle.net/2027/mdp.39015095083740