152 MR. FARADAY’S EXPERIMENTAL RESEARCHES IN ELECTRICITY. 
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 in- 
ducing 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 posi- 
tive electricity ; or reversing the motion of the first arrangement, that of fig. 17 
to fig. 19, B received negative electricity. 
1 04. 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 ob- 
tained with the revolving disc (94.). 
108. On the conductors being held against the ends of the plates, and the 
