Breaking coal with airdox

Author:	Malesky, J. S.
Year:	1948
Document Type:	USBI
Issuing Agency:	U.S. Dept. of the Interior, Bureau of Mines,
SUDOC:	I 28.27:7480
Series:	Information circular / Bureau of Mines ;
Report Number:	7480.
Subjects:	Compressed air
	Coal mines and mining--Electric equipment
	Coal mines and mining--Safety measures
	Coal mines and mining--Equipment and supplies
Link:	https://hdl.handle.net/2027/mdp.39015078463588