atived by the simplest considerations;
but a fact in proof will be better. If instead of the ball B a small disc
of metal be used, the carrier may be charged at, or above the middle of its
upper surface: but if the plate be enlarged to about 1-1/2 or 2 inches in
diameter, C (fig. 108.), then no charge will be given to the carrier at
_f_, though when applied nearer to the edge at _g_, or even _above the
middle_ at _h_, a charge will be obtained; and this is true though the
plate may be a mere thin film of gold-leaf. Hence it is clear that the
induction is not _through_ the metal, but through the surrounding air or
_dielectric_, and that in curved lines.

1222. I had another arrangement, in which a wire passing downwards through
the middle of the shell-lac cylinder to the earth, was connected with the
ball B (fig. 109.) so as to keep it in a constantly uninsulated state. This
was a very convenient form of apparatus, and the results with it were the
same as those just described.

1223. In another case the ball B was supported by a shell-lac stem,
independently of the excited cylinder of shell-lac, and at half an inch
distance from it; but the effects were the same. Then the brass ball of a
charged Leyden jar was used in place of the excited shell-lac to produce
induction; but this caused no alteration of the phenomena. Both positive
and negative inducing charges were tried with the same general results.
Finally, the arrangement was inverted in the air for the purpose of
removing every possible objection to the conclusions, but they came out
exactly the same.

1224. Some results obtained with a brass hemisphere instead of the ball B
were exceedingly interesting, It was 1.36 of an inch in diameter, (fig.
110.), and being placed on the top of the excited shell-lac cylinder, the
carrier ball was applied, as in the former experiments (1218.), at the
respective positions delineated in the figure. At _i_ the force was 112 deg.,
at _k_ 108 deg., at _l_ 65 deg., at _m_ 35 deg.; the inductive force gradually
diminishing, as might have been expected, to this point. But on raising the
carrier to the position _n_, the charge increased to 87 deg.; and on raising it
still higher to _o_, the charge still further increased to 105 deg.: at a
higher point still, _p_, the charge taken was smaller in amount, being 98 deg.,
and continued to diminish for more elevated positions. Here the induction
fairly turned a corner. Nothing, in fact, can b