Some hazards of conveyor loading in coal mines

Author:	Jeffers, C. W.
Year:	1930
Document Type:	USBI
Issuing Agency:	U.S. Dept. of Commerce, Bureau of Mines,
SUDOC:	C 22.11:6300
Series:	Information circular / United States Department of Commerce, Bureau of Mines ;
Report Number:	6300
Subjects:	Coal-mining machinery
	Conveying machinery
Link:	https://hdl.handle.net/2027/mdp.39015077576240