Note 85 — Chapter LI
Reading edition
Chalmer describing a Whirlwind, which is a
Storm
of
collection
and
Ascent
of
hot
Air, &c. by Rarefaction, says, “as the Wind ceased, presently after the Whirlwind passed, the
branches
and Leaves of various Sorts of Trees, which had been carried into the Air, continued to
fall
for
half an hour
; and, in their Descent, appeared like Flocks of Birds of different Sizes.”
This Circumstance proves that Columns of hot Air must have been raised in a Body, in Succession, to so considerable a Height, that Branches of Trees carried up by them, took half an Hour in falling.