To explain this, it is supposed that the cotton, by its connection
with the prime conductor, receives from it a quantity of its
electricity; which occasions its being attracted by the _finger_
that remains still in nearly its natural state. But when a _point_
is opposed to the cotton, its electricity is thereby taken from it,
faster than it can at a distance be supplied with a fresh quantity
from the conductor. Therefore being reduced _nearer_ to the natural
state, it is attracted _up_ to the electrified prime conductor;
_rather than down_, as before, to the finger.
Supposing farther that the prime conductor represents a cloud
charged with the electric fluid; the cotton, a ragged fragment of
cloud (of which the underside of great thunder-clouds are seen to
have many) the finger, a chimney or highest part of a building.--We
then may conceive that when such a cloud passes over a _building_,
some one of its ragged under-hanging fragments may be drawn down
by the chimney or other high part of the edifice; creating thereby
a _more easy communication_ between it and the great cloud.--But a
_long pointed rod_ being presented to this fragment, may occasion
its receding, like the cotton, up to the great cloud; and thereby
_increase_, instead _of lessening_ the distance, so as often to make
it greater than the striking distance. Turning the _blunt end of a
wire_ uppermost (which represents the unpointed bar) it appears that
the same good effect is not from that to be expected. A long pointed
rod it is therefore imagined, may _prevent_ some strokes; as well as
_conduct_ others that fall upon it, when a great body of cloud comes
on so heavily that the above repelling operation on fragments cannot
take place.