W. S. W. to some point between N. N. E. and E. N. E.
The various forms of N. W. scud move to the S. E. The March, foggy scud,
from between W. and N. W., rarely have any cirro-stratus above them, but
rather a peculiar turbid condensation.

The character of the primary condensation, the direction and force of the
wind, and the direction of the secondary condensation or scud, must be the
main reliance of the observer. But I must reiterate that they all differ
in different kinds of storms, in different seasons of the same year, and
the same seasons of different years; and the observer must be careful to
make due allowance for those differences.

There are, however, divers other secondary signs, which, although not
alone to be relied upon, will aid the observer, if carefully studied, when
the character of the clouds, and the pressure of easterly or southerly
wind and scud, are not decisive. Of these, a large class are electrical.

The smoke descends the adjoining chimney-flues, or outside of the chimney,
toward the ground.

Thus, Darwin, as quoted by Hone:

"The smoke from chimneys right ascends,
Then, _spreading_, back to earth it bends."

Smoke is electrified _positively_, by the act of combustion; the earth and
the adjacent atmosphere, when storms are gathering or approaching, is
_negative_. Hence the smoke spreads, and is attracted downward by an
opposite electricity. On the other hand, it is interesting to see, at
other times, and when the difference in temperature is not material, but
the whole atmosphere is positive, with what rapidity and compactness the
smoke will ascend in a _straight and elevated column_ from the chimney,
repelled by a similar electricity. I am aware it is generally supposed the
smoke descends because the _air is lighter_. But it is a mistake. I have
seen it descend when the barometer was at 30 deg..60, or .60 above the mean.

There is, too, a draught downward in chimneys, in such cases when there is
no smoke or fire in any of its flues. Thus Jenner says: "The soot falls
down;" whether he meant by this that there was an actual fall of soot
other than what is occasioned by the rain falling in through the chimney
top, and disturbing the soot, as sometimes happens, I do not know. It
occurs rarely, and is of very little practical importance. But every
housewife knows that chimneys, which have been used in winter, and are
full of soot, _smell_ before storms. The odor results from a downward