Lines of force indicating
the distribution of
magnetic force, which is
due presumably to whirls of
the ether. A wire or conductor through which
a current is passing is surrounded by an electro-
magnetic field of
force, q. v., whose lines of force form circles surrounding
the
conductor in question. A
magnet marks
the existence of a similar
electro-
magnetic field of force whose lines form circuits comprising
part of and in some places all of
the body of
the magnet, and which are
completed through
the air or any surrounding paramagnetic or diamagnetic
body. They may be thought of as formed by
the Ampérian sheet of
current,
and analogous to those just mentioned as surrounding a conductor.
Fig. 223.
MAGNETIC LINES OF FORCE, DIRECTION OF.
A
magnetic line of force may be thought of as a set of vortices or
whirls, parallel to each other, and strung along
the line of force which
is
the locus of their centres.
If as many lines are drawn per square centimeter as there are dynes (per
unit pole) of force at
the point in question, each such line will be a
unitary c. g. s. line of force.