A Guide To The Scientific Knowledge Of Things Familiar Part 30

Q. _Why are MORNING CLOUDS generally of a RED tinge?_

A. Because red rays are the _least refrangible of all_, and not being _bent back by the air_ (like blue and green), _strike upon the horizon_, and give a tinge to the morning clouds.

Q. _Why is not the reflection of clouds always ALIKE?_

A. Because their _size, density, and situation in regard to the sun_, vary perpetually; so that sometimes _one_ colour is reflected, and sometimes _another_.

Q. _What regulates the MOTION of the CLOUDS?_

A. The _motion of the clouds_ is generally directed by the _winds_; but sometimes _electricity_ will influence their motion also.

Q. _How do you know that CLOUDS move by OTHER influences besides WIND?_

A. Because we often see in calm weather _small clouds meeting each other_ from opposite directions.

Q. _How do you know that ELECTRICITY affects the motion of the clouds?_

A. Because clouds often meet from _opposite directions_; and (after they have discharged their opposite electricities into each other) _vanish altogether_.

Q. _Into how many CLa.s.sES are the different sorts of CLOUDS generally divided?_

A. Into three cla.s.ses:--viz. Simple, Intermediate, and Compound.

Q. _How are SIMPLE CLOUDS sub-divided?_

A. 1.--Cirrus. 2.--c.u.m'ulus; and 3.--Stra'tus.

Q. _What are CIRRUS CLOUDS?_

A. Clouds like _fibres_, _loose hair_, or _thin streaks_, are called cirrus clouds.

Q. _Why are these clouds called CIRRUS?_

A. From the Latin word, _cirrus_ ("a lock of hair, or curl"): they are the most _elevated of all clouds_.

Q. _What do CIRRUS clouds PORTEND?_

A. When the streamers point _upwards_, the clouds are _falling_, and _rain is at hand_: but when the streamers point _downwards_, expect easterly wind or drought.

Q. _What are c.u.m'ULUS CLOUDS?_

A. c.u.m'ulus clouds are lumps like great _sugar-loaves_,--_volumes of smoke_,--or _mountain towering over mountain_.

Q. _Why are these monster ma.s.ses called_ c.u.m'ULUS CLOUDS?

A. From the Latin word, _c.u.m'ulus_ (a ma.s.s or pile).

Q. _What do_ c.u.m'ULUS _clouds_ FORESHOW?

A. When these piles of cloud are _fleecy_, and sail _against the wind_, they indicate _rain_; but when their outline is very _hard_, and they come up _with the wind_, they foretell _fine weather_.

c.u.mulus clouds should be _smaller_ towards evening than they are at noon. If they _increase_ in size at sun-set, a thunder-storm may be expected in the night.

Q. _What are_ STRA'TUS CLOUDS?

A. Creeping mists, especially prevalent in a summer's evening: these clouds rise at sun-set _in low damp places_, and are always _nearer the earth_, than any _other_ sort of cloud.

Q. _Why are these mists called_ STRA'TUS _clouds?_

A. From the Latin word, _stra'tus_ ("laid low," or "that which lies low").

Q. _How are the_ INTERMEDIATE CLOUDS _sub-divided?_

A. Into two sorts. 1.--The Cirro-c.u.m'ulus; and 2.--The Cirro-Stra'tus.

Q. _What are CIRRO-c.u.m'ULUS CLOUDS?_

A. When _cirrus_ clouds spring from a _ma.s.sy centre_; or when _heavy ma.s.ses of cloud_ terminate at their edges in _long streaks_, or what are called "_mares' tails_."

A system of small round clouds may be called cirro-c.u.m'ulus.

Q. _What do CIRRO-c.u.m'ULUS clouds generally FOREBODE?_

A. Continued drought, or hot dry weather.

Q. _What are CIRRO-STRA'TUS CLOUDS?_

A. They compose what is generally called a "_mackarel sky_." This cla.s.s of clouds always indicate _rain and wind_; hence the proverb--