Saint Mary's beacon. [volume] (Leonard Town, Md.) 1867-1983, 1878-11-14

e..It - =
LUNAR DAYS AkD ElGHrs- --tNON-
pRnFUG ExTRgMKs or HEAT AND CoLD.
-DF. Klein. = German astronomer, has
recenlly called the attention o. sstFon0-
mes 10 lunar crater. some three miles
wide. which had not before been Ob-
served. and which be feels SUITE, was
not ia existence. two years 40. Is
trononers have long sinee given up all
hope Of tracing either The signs Of acttI-
al he upon The n,oon or traces Of the
past existence % Iising creatures there.
But there are still among them those
who believe that By sedulous and care
lsGl scfusint processes OF material change
NAV Be recognized IN that seemingly
inert mass. 10 reality. perhaps the
wonder rather il that signs Of change
should not be often recognized, than
HAT from time q time . new crater
should appear OF The walls Of old era
tiers fall IN. The moons surface is ex-
posed 10 variations oftemperature COM
pared with which those affecting the
surface oil our earth are altogether tri-
fling. Il Is true there Is no summer or
winter 10 The moon. @
Sir w. Herschel has spoken Of the
lunar seasons Is though they resemble
our own, but Ia reality they are very
different. The suns midday height at
any lunar station is only about three de-
grees greater in summer than in win
ter, whereas our summer sun is forty
seven degrees higher IN The sky AZ noon
than our winter sun. In, fact, mid
summers day on The moon does not
differ more from . midwinter's day, as
far as the SUMS actual path on the sky
Is concerned, than with rs the 18th OF
March differs from the 25th. or the 18th
Of September from the 9th. II is The
change from day to night which chiefly
affects the moons surface. in the lu-
mar year of seasons; lasting $40 2-S Of
our days, each lasting twenty-nine and
three. quarters Of ours. Thus day lasts
more than i fortnight, and Is followed
by q night OF equal length. Nor is this
ali. There is neither ar nor moisture
to produce such effects as are produced
by our air and the moisture il contains
in mitigating The heat Of day and cold
OF night. Under the suns rays the
moons surface becomes hotter and hot
ter as the long lunar day proceeds, un-
I'll "a lest its heat exceeds shat Of boil
ing water; but so soon as the sun has
! set the heat thus received is rapidly ra-
dated away into space (no screen Of
moisture-laden air checking its escape),
and long before lunar midnight cold
exists compared with which the bitter
est weather ever experienced by Arctic
voyagers would be oppressively hot.
These are not merely theoretical con-
illusions, though even a. such they
could be thoroughly relied upon. The
moons heat has been measured by the
present Lord Rosse (using his fathers
splendid six-foot miFror). He sepa-
rated the heat which the moon simply
reflects to Us from that which her
heated service herself gives out Tor,
technically, he separated the reflected
from the radIated heatl by using glass
screen which allowed the former heat
to pass while Il intercepted the latter.
He thus found about six-sevenths of the
heat We receive from the moon Is due
to The heating Of her own substance.
From The entire series OF observations
il appeared that the change Of tempeFa-
ture during the entire lunar day-that
is, from near midnight 10 near midday
on the moon--amounts 10 fully 500 de-
grees Fahrenheit. &c we assume that
the cold at lunar midnight corresponds
with about $50 degrees below zero (the
greatest cold experienced in Arctic
travelling has never exceeded l40 de-
grees below zerol, il would follow that
the midday heat was considerably
greater .han that Of boiling water on the
earth at the sea level. But the range
of change is not a matter Depreciation.
IL certainly amounts to about 800 de-
grees. and in whatever way we distri-
butte n, We must admit first, that no such
life as We are familiar with could pos
sibly exist on the moon; and secondly,
thar the mo0n's crust must possess q
life of its own. so 10 speak, expanding
and contracting increasingly and ener-
getically.--LOHdOn Times.