Questions and answers on Bureau of Mines approvals of electrical equipment

Year:	1927
Document Type:	USBI
Issuing Agency:	U.S. Dept. of Commerce, Bureau of Mines,
SUDOC:	C 22.11:6036
Series:	Information circular / Bureau of Mines ;
Report Number:	6036
Subjects:	Mines and mineral resources--Equipment
	Mining engineering--Equipment
	Mineral industries--Equipment
	Electric apparatus and appliances
Link:	https://hdl.handle.net/2027/mdp.39015086471375