American telegraphy and encyclopedia of the telegraph; systems, apparatus, operation (1909)
Maver, William, jr. [from old catalog] · New York, Maver publishing company · leaf 144
^ opposite points. The space within the dotted lines / may represent FIG. 92, … the plane of the coil, the small dots a section of the earths lines of force, and the curv-ed lines the lines of force that emanate from the coil. Similar curved lines mav be no AMERICAN TELEGRAPHY. assumed to emanate from every other part of the coil. It is seen in Fig. 92 that thelines nearest…
Telegraph
Internet Archive · Library of Congress · Public Domain Mark 1.0. Free to use for anything.
