ce of copper
plate one fifth of an inch thick, one inch and a half wide, and twelve
inches long, being amalgamated at the edges, was placed between the
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
effect was somewhat more, but still very small.

106. When an amalgamated copper wire, one eighth of an inch thick, was
drawn through between the conductors and poles (101.), it produced a very
considerable effect, though not so much as the plates.

107. If the conductors were held permanently against any particular parts
of the copper plates, and carried between the magnetic poles with them,
effects the same as those described were produced, in accordance with the
results obtained w