The Pacific commercial advertiser. [volume] (Honolulu, Hawaiian Islands) 1856-1888, 1857-06-04

be seen between the years 1898 ana 1901; the early
observations from which these calculations were made,
having been much less accurate than they now are.
THE AsTERODs.-It is q singular circumstance that
after the discovery of the four first and originally
known asteroids, forty years should elapse before
another should be found, although the heavens were
constantly raked during that period by the telescopes
of astronomers. But they were becoming more skill
full, and their instruments better, and from 1S45 to
1856, hirty-Sir more of the little planets were dis
covered, making forty in all. Only one, Vesta, is
visible to the naked eye. The diameter of none ex-
ceeds two hundred miles. 1t would require four hun
dred as large as the largest to form q planet one
fourth the size of the earth. The mass of the smaller
ones is so small and the attraction which they have
consequently for bodies on their surface so weak, that
if a full grown and even pretty teshy Yankee were
placed upon one of them, he could leap, with mOder-
ate exertion, to a height equal to one of our tallest
pine trees or steeples, and come down again as softly
as a bird ON q feather bed. Some have feared that
among so many asteroids, some might strike each
other, but none Of their orbits are found to intersect,
and there can be therefore no danger.
DISTANCE OF THE FIXED Observation-Disclosures have
long since tried to discover the distance of the fixed
stars. That this remOtenesS was immense, was early
known. We will briefly describe their attempts. If
we should see u very distant peak of Il mountain, we
will suppose due west, and should find after travelling
q mile to the north, that it appeared still due west,
We should know that its distance from US must be
very great. Nearer objects would alter their course
from us, and those only u mile to the west, would be-
come exactly southwest. If the mountain were q
hundred miles from us, its position would be changed
a little, which by accurate measurement with a
proper instrument would be about two-thirds of one
degree. The more remote the object, the less its po-
sition appears changed. The distance of the nearer
planets may be thus determined, with the assistance
of powerful telescopes used at the same time on re-
mote parts of the earth.
The orbit of the earth, is "a 900 times rs great as
the diameter Of the earth itself The earth, when it
has passed the breadth of its orbit, is 100 millions
miles from It's plane on the opposite side. None but
objects the size of worlds can be even seen so far.
One would therefore naturally SuODOSp that tho Hyed
stars seen from these two points, 100 million miles
asunder, would appears in quite different positions.
But no difference whatever can be perceived. Even
by means OF the most powerful telescopes, the slight
est change i'll position could not be determined, al
though they were capable of detecting q difference
only one three-thousandth part of a single degree.
Nothing satisfactory was determined until 1887, when
another way of measuring was adopted. Two stars,
apparently very near together, were selected. Their
apparent distance asunder was then measured by
means OF q powerful telescope connected with a most
perfect micrOmeter. Six months afterwards, their
distance from each other was measured again. If one
star was really much beyond the other, this mode
would be likely to show a slight difference. With a
few stars, this was found actually to be the case.
Some were found to change their apparent position
on opposite sides of the earth's immense orbit, the
difference amounting to one six-thousandth part of a
degree-wlth others, it was only one ten-thousandth,
or one twenty-thousandth part. By accurate calcula-
ton, the distance was determined. The following are
some Of the results
The nearest fixed star determined, is O very bright
star (quite as bright as Sirius) in the Southern hem
isphere, known as Alpha Centauri, not seen here at
the north. Light, which flies 1870 thousand miles per
second, would be more than three years coming from
it. Sirius Cor the dog starr is about three times as
remote, or sixty millions of millions of miles, and it's
light would be ten years reaching us. The North
star is ten times as far as the first named, and it's
light Is thirty years travelling to us; so that, if it were
destroyed to-day, it would continue to guide the wan
derer for thirty years to come.
a railway train, so swift as to travel from New
York to st. Louis in a day, would be 500 years ira
Verslng the breadth of the earth's orbit; and be six
millions of years reaching the nearest fixed star, and
sixty millions of years reaching the North star. Had
such a train left the earth in the days of Adam, and
been flying on ever since, it would now have passed
over just one ten-thousandth part of its journey to
the polar star.
Several of the fixed stars are found to have a real
progressive motion through the heavens, and the rate
at which they are thus travelling onward through the
immense regions of space, can be nearly determined.
The one which appears 10 have the most rapid appa-
rent motion, is a small star in the leg of the great
bear. Its real velocity is found to be SO enormous
that it clears about a million miles every hour, or two
hundred and fifty miles Il second. It is not quite so
distant from us as the polar star, yet such is its re-
mOteness, that with this astonishing velocity, it has
moved only one degree in five hundred years!
THE Sun IS MOVING ONwARD.-The discoveries of
astronomers of late years, have proved that the sun
with oil the solar system, is travelling onward through
space, towards the constellation Hercules. Some sup
pose it to be sweeping around in an immense orbit,
and that Pleiades is the grand center. This is not
certain; but its progressive motion is demonstrated;
for the stars on one side Of the heavens are slowly
closing, and ON the other side separating like an ope-
ming vista; while Internationally, they are passing
towards the closing side. This motion is so slow ap-
parently, as to be ascertained only by long Observa-
ton with the most powerful. Instruments. The veloc-
ity Of the sun is about twenty thousand miles an
hour, or four hundred times faster than the swiftest
railway trains.
The SIZE OF THE SUN.-Thi is not n late discovery,
yet az estimate may assist the Imagination. The moon
is two thousand miles in diameter, but is nevertheless
so far off as to appear no larger than a common-sized
cheese-its distance being two hundred and forty
thousand miles. The whole breadth of its orbit
around the earth is but One-half the breadth of the
suns face. 4 railway train would be six years in
traversing the sun. If the earth were represented by
a ball an inch in diameter, the sun on the same scale,
would be rs large as a seven-story brick building. 1t
is nearly n million miles in diameter, aud yet not
outstanding its dazzling brilliancy if it was seen as
far off as the nearest fixed star, it would be but q
twinkling point, only to be seen in the darkness of
night.
The MILKY-WAY.-This faint cloud is resolved by
powerful telescopes into millions of stars. J. f. Her
shell, with his 20 feet reflector, calculated the number
seen with that, at about five millions, with many so
faint and numerous that he could not count them
while there appeared to be obscure clouds of stars be-
yond, that the power of his telescope could not dis
tinguish. When Lord Rose made his great telescope
CSC #. long, 6 #. diameter, and costing $6O,O0O) he
still found myriads Of stars not seen before, while in
lho Doi1Ev-I Eay and in nvnrv mart of tho hpaVpDS thprn