Suggested hoisting-signal code for metal-mine shafts

Author:	Harrington, D.
Additional Authors:	East, J. H.
Year:	1944
Document Type:	USBI
Issuing Agency:	U.S. Dept. of the Interior, Bureau of Mines,
SUDOC:	I 28.27:7289
Series:	Information circular / United States Department of the Interior, Bureau of Mines ;
Report Number:	7289
Subjects:	Hoisting machinery
	Mineral industries--Safety measures
	Mine hoisting--Safety appliances
Link:	https://hdl.handle.net/2027/mdp.39015074127153