Practical uses of the earth's magnetism
By: by David G. Knapp, assistant mathematician.
Contributors: Knapp, David Goodwin, 1907-; United States. Coast and Geodetic Survey.
Series: Serial; no. 618
Publisher: U.S. Govt. print. off.
Published: 1939
Place of publication: Washington
Language: eng
Number of pages: 19
Subjects: Geomagnetism.
Notes: "Publications on terrestrial magnetism": p. 16-17.
At head of title: U.S. Department of commerce. Harry L. Hopkins, secretary. Coast and geodetic survey. Leo Otis Colbert, director.