The Savannah morning news. (Savannah, Ga.) 1900-current, 1900-06-27
SOMETHING NEW ABOUT VENUS.
How 1t Has Been Learned That IT'S
Dny Resembles Ours.

fONu inc LONDON man.
An accomplished astronomer has Just
made a discovery in the heavens which
merits our close attention, for It amplifies
our knowledge of the condition of an in
teresting neighboring world That neigh
boring world is the beautiful planet Ven
u.s. and that the discovery should have
been made just now will occasion no sur
prise TO any one who has watched the
brilliant orb which has for weeks been
adorring our evening sky.
Venus possesses a special and particular
interest from the circumstance that ii is a
globe which in many respects has a start
ling resemblance to our own earth. To
begin with the beautiful evening star is
almost exactly the same size as the
globe on which we dwell The number
of miles traversed in making a voyage
around the equator of the earth would
be almost identical with the number of
miles which would make an equatorial
girdle for Venus Nor does the re-
semblance between the earth and the
planet consist merely in their equal size
The two globes have practically the same
weight.
If we imagine pair of weighing scales
so mighty that Venus could be put into
one pan and the earth into the other, no
great difference would be perceived he
tween tne weight OF tne TWO CELESTIAL
orbs. Two billiard balls which had no
greater proportional difference in size
and weight than the earth and Venus
would be practically indistinguishable.
The resemblance between these twin plan
cts has however. been carried much
further by the interesting discovery which
has just been announced to astronomers,
and which l shall now attempt to de-
scribe.
To planet which may be the abode OF
life, one of the most important conditions
will be the succession of day and night.
Whenever the question as to the resem-
blance of another world to our earth is
raised it is natural TO consider how far
the inhabitants OF such a world, If in
habitants there be, resemble ourselves in
the enjoyment of the alterations of day
when the sun is in the skies with a night
when the sun is below the horizon. The
change from day to night. the change from
night TO day. are, Of course. consequences
of the rotation of the planet on its axis.
We desire to learn how far the period
which the planet requires to complete each
turn may agree or disagree with the time
required by the earth for a like move
ment To put the matter more definitely,
we may inquire how far the period re-
quired by Venus to rotate on its axis cor
responds with that period of twenty-four
hours and fifty-six minutes, which eX
complete one revolution about it's axis.
The determination of the length Of the
day and the length of the night to which
the inhabitants of Mars must accomno-
date their domestic arrangements has new
er admitted of much doubt. Indeed, we
know the length of the day on Mars TO
single second of time. This determine
ton has been made so accurately because
the marks on Mars are clear enough to
be precisely identified. After the lapse of
years, or after the lapse of even centu-
ries, those marks are stin to be seen, with
out any doubt whatever in each revotu-
ton Of the planet. But for the study of
the length of day and the length of night
on Venus the face of the beautiful even
ing star offers no such facility This
globe has no well-marked features there
are no definite spots to sully the brilliant
mantle of sunbeams characteristic of the
evening star
One very eminent astronomer thought
that the day in Venus must be enormously
long; must, in fact, last for about fifteen
weeks, while the night which succeeded II
had to last for fifteen weeks more. The
discrepancy showed that the marks on the
planets globe were not sufficiently def-
mite to solve the problem. Such marks
as could be seen with more or less dis
tinctness were most probably merely
clouds in the atmosphere of the planet,
and consequently had no permanence.
Some other method of solving the problem
not exposed to such difficulties wes clear
ly necessary.
A totally new method of attacking the
question has been applied to Venus dur
ing the present apparition by the astrono-
mer Belopolski. He has abandoned alto
gether the search for permanent marks
on the planet. As the planet turns round
one edge comes toward US and the other
edge goes from u.s. If the period be the
short one, Ike our own day, then the edge
which is advancing toward US will move
more rapidly than 1t would be moving IL
the period were to be expressed by months.
1t is easy to see that by determining the
rate at which the advancing edge is COM
ing toward US it is possible to calculate
what the duration of the whole rotation
must be.
A beautiful new process permits this 10
be done. Belopolski found that the edge
of the planet coming toward the earth
is moving faster than 1t would be If the
long period of rotation we're adopted, and
he has therefore determined that we must
accept the short period. Thus a most
difficult question has been set at rest. To
the other analogies between the earth and
its twin globe. Venus we have now TO add
that the day and night for any inhabitant
on that world succeed each other in much
the same fashion as day and night sue
coed each other on this earth.