as equally unsuccessful in her efforts to prevent the civil
discords between her children. She died in 544, and was buried by her
husband's side in the church of the Holy Apostles.

There is a mediocre _Life_ in _Mon. Germ. Hist.: Script. rer. Merov._,
vol. ii. See also G. Kurth, _Sainte Clotilde_ (2nd ed., Paris, 1897).
(C. PF.)

CLOUD (from the same root, if not the same word, as "clod," a word
common in various forms to Teutonic languages for a mass or lump; it is
first applied in the usual sense in the late 13th century; the
Anglo-Saxon _cl[=u]d_ is only used in the sense of "a mass of rock,"
_wolcen_ being used for "cloud"), a mass of condensed vapour hanging in
the air at some height from the earth.

_Classification of Clouds._--The earliest serious attempt to name the
varieties of cloud was made by J.B. Lamarck in 1801, but he only used
French terms, and those were not always happily chosen. The field was
therefore still clear when in 1803 Luke Howard published, in _Tilloch's
Philosophical Magazine_, an entirely independent scheme in which the
terms were all Latin, and were applied with such excellent judgment that
his system remains as the broad basis of those in use to-day. He
recognized three primary types of cloud--Cirrus, Cumulus and
Stratus--and four derivative or compound forms,--Cirro-cumulus,
Cirro-stratus, Cumulo-stratus and Cumulo-cirro-stratus or Nimbus.

His own definitions were:--

(1) _Cirrus._--Parallel, flexuous or diverging fibres, extensible in
any or all directions.

(2) _Cumulus._--Convex or conical heaps, increasing upward from a
horizontal base.

(3) _Stratus._--A widely-extended continuous horizontal sheet,
increasing from below.

(4) _Cirro-cumulus._--Small, well-defined, roundish masses, in close
horizontal arrangement.

(5) _Cirro-stratus._--Horizontal or slightly inclined masses,
attenuated towards a part or the whole of their circumferences, bent
downward, or undulated, separate or in groups consisting of small
clouds having these characters.

(6) _Cumulo-stratus._--The cirro-stratus blended with the cumulus, and
either appearing intermixed with the heaps of the latter or
superadding a widespread structure to its base.

(7) _Cumulo-cirro-stratus, or nimbus._--The rain-cloud: a cloud or
system of clouds from which rain is falling. It is a horizontal sheet,
above which the cirrus spreads, while the cumulus enters it la