Principal facts of the earth's magnetism and methods of determining the true meridian and the magnetic declination. Reprinted from the United States magnetic declination tables and isogonic charts for 1902 (1909)
U.S. Coast and Geodetic Survey · Washington Govt. Print. Off · leaf 121
yors compasses have been found to differ at times as much as ;4° to 1° from the readingswith the Coast and Geodetic Survey magnetometers. c For a further description of methods and instruments, the reader is referred to the special papergiving directions for measurements in terrestrial magnetism,… … FIG. 28.—COAST AND GEODETIC SURVEY MAGNETOMETER. TRUE M-ERIDIAN AND MAGNETIC DECLINATION. 97 suspended by two or three silk fibers and capable of being inverted in its stirrup,the magnet taking the place of the magnetic needle in the ordinary survejors compass. The fiber suspension avoids the…
Magnetism, Terrestrial
Internet Archive · Gerstein Library, University of Toronto · Public Domain Mark 1.0. Free to use for anything.
