for a magnet, a flat piece for the blade, and a piece of thread connecting
one end of the cylinder with the other, and passing through a hole in the
blade, for the magnetic curves: this readily gives the result of any
possible direction.

117. When the wire under induction is passing by an electromagnetic pole,
as for instance one end of a copper helix traversed by the electric current
(34.), the direction of the current in the approaching wire is the same
with that of the current in the parts or sides of the spirals nearest to
it, and in the receding wire the reverse of that in the parts nearest to
it.

118. All these results show that the power of inducing electric currents is
circumferentially exerted by a magnetic resultant or axis of power, just as
circumferential magnetism is dependent upon and is exhibited by an electric
current.

119. The experiments described combine to prove that when a piece of metal
(and the same may be true of all conducting matter (213.) ) is passed
either before a single pole, or between the opposite poles of a magnet, or
near electro-magnetic poles, whether ferruginous or not, electrical
currents are produced across the metal transverse to the direction of
motion; and which therefore, in Arago's experiments, will approximate
towards the direction of radii. If a single wire be moved like the spoke of
a wheel near a magnetic pole, a current of electricity is determined
through it from one end towards the other. If a wheel be imagined,
constructed of a great number of these radii, and this revolved near the
pole, in the manner of the copper disc (85.), each radius will have a
current produced in it as it passes by the pole. If the radii be supposed
to be in contact laterally, a copper disc results, in which the directions