Sacramento daily record-union. [volume] (Sacramento [Calif.]) 1875-1891, 1888-03-17
THE MOON.
PLANET COMPANION WORLD OF
THE EARTH.
Interesting Data Concerning the
Physical Features of Our Night
Luminary, by Prof Proctor.

The moon, regarded as an object of
physical study, occupies unique position
among the members of our solar system.
Some Of the other planets-for the moon,
be it remembered, is planet, a companion
world Of the earths, no mere satellite
tell us of the past of our earth's career /;
Others again tell us of the future; but the
moon speaks both of the past and future of
world life. We can study her surface to
learn what our earth will be like when
old age and death overtake her; but We
can also study the moons surface to learn
something about our earth's condition in
the past. She retains the record of stages
of life through which she passed millions
of wears ago, and through which our earth
has also passed but from the earth's face
the record of these past stages have been
in great degree removed or blurred and
defaced till we are unable to read them
Alright
1t is easy to see why the moons surface
should be much less affected by atmos-
pheric and aqueous wear and tear during
the past ages when she had an atmosphere
and when she had seas. In the first place
the period of time during which she was
thus clothed with air and water, must have
been much shorter than the corresponding
period for the earth. As much the smaller
orb, having in fact but the eighty-first part
of the earth's mass, she would necessarily
cool far more rapidly-probably Though /
will not here enter on the calculations
which Indicate the probability about six
times faster than the earth; so that if we
set the past duration Of the years fitness
for life at 100000 years, which geolo-
gists would regard as a moderate esti-
mate for the duration of the Archean.
primary, secondary, tertiary and recent
eras, we should have to regard 10000
900 Of years as the duration of the cor
responding part of the moons life The
work Of denudation which has gone on
upon the earth during the past 60,000,00
of years could not possibly have been ac-
complished upon the moon during 10000
600 years, even though the work had pro-
ceeded century by century, at the same
rate. But it could not proceed nearly so
fast on the moon as on the earth. To be-
gin with, there must have been much less
air and water per square mile of the
moons surface than on the earth's in CORE
spending portions of the life of each
Assuming the air and water to be the same
proportions of the total mass of each
planet. the earth had eighty-one times as
much air and water as the moon, and the
earth's atmosphere and water covered a
surface not eighty-one times but only
thirteen and one-half times the surface
&c L.. hot
BILE assumption as to the quantity of
air and, wather present on the two planets,
the earth had six times as much air
and water over each square mile of her
surface as the moon had at the correspond
ing stages of her life as a world. With a
sixth part only Of these, the instruments
of denudation, the moon had also but a
sixth part of the energy with which to
work them. Gravity on the earth is six
times as strong as gravity on the moon !;
and gravity ON each planet was the hand
by which air and water, the tools of de-
mutation, were worked. With tools hay
ing but one-sixth the efficiency, the
force of lunar gravity having but one
sixth the energy of terrestrial
gravity, and working for but sixth
part of the time, could do no such
work in destroying the primeval fea-
lures of the planet as has been accom-
plished on our earth. We may then ex-
pect to find in the crust of the moon,
stripped as it now is of the air and water
which once surrounded it, the records of
the original rock surface corresponding to
the Archaan rocks of our earth.
Biologists admit that the condition of
the earth's surface before the primary
strata began to be formed cannot be salts
factorily determined. Although certain
parts of the still remaining crust are
called Archean, it is very doubtful
whether they really represent the prime
val crust There is a much better chance
that in portions of the moons surface the
primeval rock will still remain in some
thing like its prlmeval condition
so that we may be able TO read
portion of the past history OF
the earth better in our neighbor
world, the moon, than in our own, Just as
as we can form better idea of the nature
of our savage ancestry by studying the
ways and manners of less civilized races OF
to-day than from any evidence that we can
obtain from the study of the records OF
our own race. Thus studying the moon
we see the traces of the earlier vulcanian
stages of her career, stages such as
our own earth and every planet
passes through. We see first how the
still plastic crust was riven for distances OF
many hundreds of miles by the action of
the interior forces and we can see where
molten matter flowed through those riffs
and spread in ribbon-like strips over the
hidden seams. Later, as the process Of
contraction began chiefly to affect the
crust, while the nuclear matter retreated
from it, we see how immense corrugations
were formed, akin to those of wrinkled
skin or of shrivelled apple.
OF these stages of earth-life traces still
remain. Biologists had indeed already
shown that the earth must have passed
through them. But the evidence in the
earth's case is reconcile and obscure. In the
moons it is striking and obvious. Geolo.
gists had to study the structure of strata
deep down below those which form the
main portions of mountain masses, before
the came on evidence of that primeval rift
ing followed by the outflow of molten mat.
ter which led to the sinking of the crust
in the parts thus broken and overloaded
and to their receiving larger supplies Of
matter deposited on the trough-like por.
lions Oh the sea llOOT tUtis lOruleu. vi lnS
original corrugations formed later, as the
ancient crust contracted, we have evidence
in the existence of mountain ranges-not
that mountain ranges are themselves such
corrugations, as was once supposed, but
that it has been by the contraction OF the
crust, necessarily leading to crumpline
and wrinkling of its substance, that the
material of the mountain ranges was raised
above the sea level. This material was de-
posted originally in the trough-like depres
nsjust referred to, to depths amounting ii
some cases to ten or twelve miles. Under the
side pressures exerted on the contracting
crust these immense seams OF matter were
shouldered, so to speak, above the NEAR
level, to greater and greater nights, unit
those pressures had expended their ener
gieS. On the moon we can in many place
see the corrugations themselves into which
the crust was crumpled in the process o
contraction.
On the moon, again, we find an immens'
number of craters, ranging in size from
mere saucer-shaped depressions less THAI
half mile wide to gigantic craters hav
ing a span of more than 100 miles. Ii
~, rinorc ranoa from, fau