, there is less chance of moisture being thrown down from them
by the mixture with cold air; but when the warm and moist air is
close to the surface, it is almost certain that, as the cold air
flows down into it, a deposition of water will take place.

_Poiet_. I have often seen sea-gulls assemble on the land, and
have almost always observed that very stormy and rainy weather was
approaching. I conclude that these animals, sensible of a current of
air approaching from the ocean, retire to the land to shelter
themselves from the storm.

_Ornither_. No such thing. The storm is their element; and the
little petrel enjoys the heaviest gale, because, living on the
smaller sea-insects, he is sure to find his food in the spray of a
heavy wave--and you may see him flitting above the edge of the
highest surge. I believe that the reason of this migration of
sea-gulls, and other sea-birds, to the land, is their security of
finding food; and they may be observed, at this time, feeding
greedily on the earth-worms and larva, driven out of the ground by
severe floods: and the fish, on which they prey in fine weather in
the sea, leave the surface and go deeper in storms. The search after
food is the principal cause why animals change their places. The
different tribes of the wading birds always migrate when rain is
about to take place; and I remember once, in Italy, having been long
waiting, in the end of March, for the arrival of the double snipe in
the Campagna of Rome, a great flight appeared on the 3rd of April,
and the day after heavy rain set in, which greatly interfered with
my sport. The vulture, upon the same principle, follows armies; and
I have no doubt that the augury of the ancients was a good deal
founded upon the observation of the instincts of birds. There are
many superstitions of the vulgar owing to the same source. For
anglers, in spring, it is always unlucky to see single magpies,--but
two may be always regarded as a favourable omen; and the reason is,
that in cold and stormy weather, one magpie alone leaves the nest in
search of food, the other remaining sitting upon the eggs or the
young ones; but when two go out together, it is only when the
weather is warm and mild, and favourable for fishing.

_Poiet_. The singular connexions of causes and effects, to
which you have just referred, make superstition less to be wondered
at, particularly amongst the vulgar; and when two facts naturally
unconnected, have been a