accompanies and foretells fine weather. In changeable weather
it sometimes evaporates almost as soon as it is formed; or it appears
suddenly, and then soon passes off to some other modification.

In fair weather this cloud has a moderate elevation and extent, and a
well-defined rounded surface. Before rain it increases more rapidly than
at other times, and appears lower in the atmosphere, with its surface
full of loose fleeces.

The formation of large cumuli to leeward, in a strong wind, indicates the
approach of a calm with rain. When they do not disappear or subside
about sun-set, but continue to rise, thunder is to be expected in the
night.

Independently of the beauty and magnificence which this description of
cloud adds to the face of nature, it serves to screen the earth from the
direct rays of the sun; by its multiplied reflections to diffuse and, as
it were, economise the light; and also to convey immense stores of vapour
from the place of its origin to a region in which moisture may be wanted.

THE STRATUS, OR FALL-CLOUD.

As the Cumulus belongs to the day, so does the Stratus to the night. It
is the lowest of all the clouds, and actually rests upon the earth, or
the surface of water. It is of variable extent and thickness, and is
called _Stratus_, _a bed_ or _covering_. It is generally formed by the
_sinking_ of vapour in the atmosphere, and on this account has been
called _Fall-cloud_. It comprehends all those level, creeping mists,
which, in calm evenings, spread like an inundation from the valleys,
lakes, and rivers, to the higher ground. {85} But on the return of the
sun the beautiful level surface of this cloud begins to put on the
appearance of cumulus, the whole, at the same time, rising from the
ground like a magnificent curtain. As the cloud ascends, it is broken up
and evaporates or passes off with the morning breeze. The stratus has
long been regarded as the harbinger of fine weather; and, indeed, there
are few days in the year more serene than those whose morning breaks out
through a stratus.

[Picture: The Stratus, or fall-cloud]

THE CIRRO-CUMULUS, OR SONDER-CLOUD.

The cirrus having continued for some time increasing or stationary,
usually passes either to the cirro-cumulus or to the cirro-stratus, at
the same time descending to a lower station in the atmosphere.

The Cirro-cumulus is formed from a cirrus, or a number of small separate
cirri, pas