magnetic poles, whilst the two conductors from the galvanometer were held
in contact with its edges; it was then drawn through between the poles of
the conductors in the direction of the arrow, fig. 16; immediately the
galvanometer needle was deflected, its north or marked end passed eastward,
indicating that the wire A received negative and the wire B positive
electricity; and as the marked pole was above, the result is in perfect
accordance with the effect obtained by the rotatory plate (99.).

102. On reversing the motion of the plate, the needle at the galvanometer
was deflected in the opposite direction, showing an opposite current.

103. To render evident the character of the electrical current existing in
various parts of the moving copper plate, differing in their relation to
the inducing poles, one collector (86.) only was applied at the part to be
examined near to the pole, the other being connected with the end of the
plate as the most neutral place: the results are given at fig. 17-20, the
marked pole being above the plate. In fig. 17, B received positive
electricity; but the plate moving in the same direction, it received on the
opposite side, fig. 18, negative electricity: reversing the motion of the
latter, as in fig. 20, B received positive electricity; or reversing the
motion of the first arrangement, that of fig. 17 to fig. 19, B received
negative electricity.

104. When the plates were previously removed sideways from between the
magnets, as in fig. 21, so as to be quite out of the polar axis, still the
same effects were produced, though not so strongly.

105. When the magnetic poles were in contact, and the copper plate was
drawn between the conductors near to the place, there was but very little
effect produced. When the poles were opened by the width of a card, the