ove the
earth's surface. When viewed from the summits of the highest mountains
they appear as distant as from the plains. Another proof of their great
height is, their continuing to be tinged by the sun's rays in the evening
twilight with the most vivid colours, while the denser clouds are in the
deepest shade.

The cirrus appears to be stationary; but, on comparison with a fixed
object, it will sometimes be found to make considerable progress.

THE CUMULUS, OR STACKEN-CLOUD.

"And now the mists from earth are clouds in heaven:
Clouds, slowly castellating in a calm
Sublimer than a storm; while brighter breathes
O'er the whole firmament the breadth of blue,
Because of that excessive purity
Of all those hanging snow-white palaces,
A gentle contrast, but with power divine."

The Cumulus is a day cloud; it usually has a dense, compact appearance,
and moves with the wind. In the latter part of a clear morning a small
irregular spot appears suddenly at a moderate elevation. This is the
nucleus or commencement of the cloud, the upper part of which soon
becomes rounded and well defined, while the lower forms an irregular
straight line. The cloud evidently increases in size on the convex
surface, one heap succeeding another, until a pile of cloud is raised or
_stacked_ into one large and elevated mass, or _stacken-cloud_, of
stupendous magnitude and beauty, disclosing mountain summits tipped with
the brightest silver; the whole floating along with its point to the sky,
while the lower surface continues parallel with the horizon.

[Picture: The Cumulus, or stacken-cloud]

When several cumuli are present, they are separated by distances
proportioned to their size: the smaller cumuli crowding the sky, while
the larger ones are further apart. But the bases always range in the
same line; and the increase of each cloud keeps pace with that of its
neighbour, the intervening spaces remaining clear.

The cumulus often attains its greatest size early in the afternoon, when
the heat of the day is most felt. As the sun declines, this cloud
gradually decreases, retaining, however, its characteristic form till
towards sunset, when it is, more or less, hastily broken up and
disappears, leaving the sky clear as in the early part of the morning.
Its tints are often vivid, and pass one into the other in a most pleasing
manner, during this last hour of its existence.

This cloud