_If cloudy, and it soon decrease._ } Certain fair Weather.
I Conceive the Reason of this to be, that the Vapours being then
specifically lighter than the Air, are still rising upwards, in which
they are assisted by the Heat of the Sun Beams, agreeable to the Notion
of Dr. _Derham_, who observes, that after much cloudy Weather, it is
always fair before it rains, because the watery Vapours are not
condensed till they reach the cold upper Region, agreeable to the
common _English_ saying,
The Evening red, and Morning grey,
Is a Sign of a fair Day.