Electric switches for use in gaseous mines
By: by H.H. Clark and R.W. Crocker.
Contributors: Crocker, Ralph W., joint author.
Series: [U.S.] Bureau of mines. Bulletin 68
Publisher: Govt. Print. Off.
Published: 1913
Place of publication: Washington
Language: eng
Number of pages: 38
Subjects: Electric switchgear.; Electricity in mining.
Notes: "Publications on mine accidents and methods of mining": p. 37-38.
At head of title: Department of the Interior. Bureau of Mines. Joseph A. Holmes, director.
On verso of t.-p.: First edition. November, 1913.