, 1912-03-30

ing that in reality he does nothing Of the
sort, but that it is ourselves who are carried
round on the rolling earth to meet him, so
we may be allowed to speak Of the rings as
round the sun, knowing that this is very
very far from the truth Whit is the truth
here -? Looking up at the rings we can see
that they are formed on a thin layer of cloud,
cloud of the kind called cjrro ~struttts, which
is known to be five or six miles above the
eaIth's surface. The rings are formed then
in our ntmosphere; but the sun, where is hrE
lie LO0bS like a small body in the centre of
the rings up there, but that is because OF
his vast distance from las. 1t is impossible
for us to have any feeling Of what SO great
a length as 80 millions of English miles is
like, but that is our suns distance from us.
He is of immense size also, SO great that it
would take about u million bodies the size
Of our earth to make him up. and it is this
great size that makes him, at that vast dis
tance, show up So we'll as he does ; we're he,
say, the same size as our earth, he would
only be as bright as, al ordinary star is Tor
us now.
The connection Of the sun with the rings
then is thus that his hight shining through
the ctrro-str0tus clouds produces the peculiar
effects we see. This conclusion leads naturally
to the next step, an inquiry as to these par
ticular clouds.
What are the ci1ruS Clouds 2 Iii has al
ready been said that these clouds are COM
monty five or six miles high. Their heights
have often been measured by ms rUments
mnde for such purposes and have been
found as stated, though some have been seen
much higher. The low clouds on the other
hand have their bases under q mile III height.
In appearance the cirrus clouds are generally
fbrous,a as if made of sijky or woolly threads and
80. -.-l -, Ll~,, ~-,an ~"
lcirruS, u curt.) Often they are Of Remark
able beauty. Here i'll the West Indies they
commonly move from west to. east, in the
higher current Of air called the Return
Trade Wind, the lower current, i'll which.
We live, being from east to west and called
the Z10de Wind. The cjrrO-str0GUS clouds
ere Halter forms, generally a !i,tl4 lower than
cirrus.
En- connection with the present subject.
however, the temperature OF these clouds
is the question OF greatest interest. They
are icy cold. How do we know that ? We
know it from, the fact that as we ascend
either by climbing Il high mountain or going
up in a balloon the ali gets colder and cold
Ell till at last we come to snow on the noun
tain top. This is a remarkable fact which
without experience or reading we should
never have suspected. In fact the present
writer remembers puCIlnS II question: Oh lulS
point to u young man, who wrote III reply
that the oil gets warmer as we go up, be-
cause we get nearer the sum, a position
which he illustrated by saying that if II kite
could be got to go high enough it would
take fire from the suns heat. The young
man appeared to be much astonished when
told that the case was just the opposite
to what he had supposed. Perhaps he didn't
believe that after all, for his own argument
about getting nearer the source of heat
must have seemed to him pretty nigh un-
answeruble. But you and l, dear young
reader, who know how vastly distant the
sun is, know also that there could conse-
quently be no question of getting any more
heat from him by such u snippet Of q rise
as five or SIX miles. And we may conse-
quentIy dismiss the distance Of the sun from
consideration and look for some other cause.
The decrease OF temperature with the in-
crease of height certainly exists, and is
very considerable. Mountains over IL, 900
feet high are capped with perpetual snow,
even under the equator, the hottest part OF
the globe, aud III BALBOA asceuts long ago
it has been found chat in The air away from
mountain surfaces the temperature falls