Since September last, having been abroad on two long journeys, and
otherwise much engaged, I have made but few observations on the
_positive_ and _negative_ state of electricity in the clouds. But Mr.
Kinnersley kept his rod and bells in good order, and has made many.
Once this winter the bells rang a long time, during a fall of snow,
though no thunder was heard, or lightning seen. Sometimes the flashes
and cracks of the electric matter between bell and bell were so
large and loud as to be heard all over the house: but by all his
observations, the clouds were constantly in a negative state, till
about six weeks ago, when he found them once to change in a few
minutes from the negative to the positive. About a fortnight after
that, he made another observation of the same kind; and last Monday
afternoon, the wind blowing hard at S. E. and veering round to N. E.
with many thick driving clouds, there were five or six successive
changes from negative to positive, and from positive to negative,
the bells stopping a minute or two between every change. Besides
the methods mentioned in my paper of September last, of discovering
the electrical state of the clouds, the following may be used. When
your bells are ringing, pass a rubbed tube by the edge of the bell,
connected with your pointed rod: if the cloud is then in a negative
state, the ringing will stop; if in a positive state, it will
continue, and perhaps be quicker. Or, suspend a very small cork-ball
by a fine silk thread, so that it may hang close to the edge of the
rod-bell: then whenever the bell is electrified, whether positively
or negatively, the little ball will be repelled, and continue at some
distance from the bell. Have ready a round-headed glass stopper of a
decanter, rub it on your side till it is electrified, then present
it to the cork-ball. If the electricity in the ball is positive, it
will be repelled from the glass stopper as well as from the bell. If
negative, it will fly to the stopper.