Frostburg mining journal. [volume] (Frostburg, Md.) 1871-1913, 1891-01-24
FEATS OF PHOTOGRAPHY.
HOW THE STARS ARE MULTI
Piled.

w OnueTS Oh pm 10Y dpIlA, SIeat Us
they are, are not C fined TO the world
we live in. They not consist only in
furnishing faithful pictures of human
faces, FORMS trees, houses, leaping
horses, and projecules fired from the
mouth of cannon. They extend beyond
the planet and inclu,ie the moon and
the sun. Nay, pho,o ;raphy reac hes be-
yond the sun to the stars-and even be-
yond the visible stars into what may he
called the invisible universe. rhe pho
tographcr may set up his cam a under
the II oonles5 sky in a dark ngAt and
produce specters of stars lying SO far cut
in the confines Of the stellar universe
that even the giant eye of the telescope
fails to reveal them.
The dist nee OF these Photographic
stars, whose eX stence is known of only
by the sppcters they leave aft II half an
hours exposure on the eXq isite gela.
tine film of tie artist, are inconce.v bic,
OF course, and the ii tempt To grasp the
numerical eXpressi II of them only stag
gers the mind, but the human minI is
very ingenious. 1t may do in one day
what it can not do IN another. And Il
cannon ball illustration which COM
bines motion and time i'll the same
phenomenon enables us to for II some
idea of these tremendous ste3lor dis
tanCcs A modern bot starts from the
muzzle of a riflei gln with a move
ment of about 1,0O0 miles an hour,
which is the rate of the eartl's axial
rotation at the equl,pr. Suppp e one f
these bolts were endowed with the power
of maintaining its italveIocity, and of
moving perpetualiy forward in a
straight line without being arrested hy
the attraction of any one Of the
heavenly bodies near which it Should
pass; and suppose, further that it We're
fired straight at Alpha Centauri The
chief brilliant in the Southern constel
lation of the Cntaur, and believed 10
be the nearest fixed star to the ca tn;
and imagine that so re daring and adj
venturous explorer should manage 20
mount it at the moment it emerged
from the mu2ze.
In 10 days he passes close to and
abreast of the moon, and is appalled, t
the solitude and de3oiatiOn of that
crater plttei cjnder But tie satellite
is soon left beii AMI in tx and Il half
years the explorer IL cEle5 and crosses
the orbit Of Mars ID enters a region
infested with plane ids, air stones, and
OF .er cannor l. $ If forlu rate
enough to pass through these sua'ms
without being beaten to pieces, in As
years more he crosses the track of the
giant planet of our system. SiXtr years
more brings him to he oi bit cf Saturn,
and still another period OF l30 years
brings him to the orbit of Uranus 1t
is growing dark and cold, and the ad-
venturer experiences a feeling of
horror on looking back at finding that
the earth has disal peared, and the sun
itself has Shrllnk to the size of his fist.
Nevertheless he continues on his course
AID, after another long and weary
period of 123 wears, reaches the orbit of
Neptune, the first horn and most distant
of the solar fanny He is now on the
frontier of the solar system; but he is
4l0 years old, allowing him to have
been 21 when he started. and, although
he has travelled $500, 600 900 miles, or
30 times the dis iance of the earth from
the sun, he is amazed and scouraged
at finding that he has taken only ii step
in the prodigious journey. The Centaur's
chief brilliant is no larger and brigh er,
an |, apparently, no nearer than when
he starte |. And no wonder-for be-
fore him stretches an abyss 5000 times
as wide as the distance lie has traversed.
1t would take that cannon bolt plung-
inc into tI,a coll Il ,lo,+Ie DDn OOO
years to cross it and reach the point of
destination.
And yet Alpha Centauri is our nearest
neighbor OF the fixed stars. What
astronomers call its paraIactic angle is
nine-tenths of second, a very large
angle when compared with the inappre-
cable ones of more remote stars. Many
of the brilliant points Of hgl that
attract the eye on a clear moonless
nj ;'t are >, TO- Is, and 20 times farther
on than it, A ray of light moves with
such inconceivable velocity that it might
wrap itself eight times round the earth
between two ticks of a clock, and yet it
would take that ray of ligh, 80 years to
come from the North Star to the earth.
When we look at the steadfast unchang-
ing sentinel of the pole at night we see
it in the light that left it half century
ago, and if the omuipotent hand that
formed it, wisely set it in its place,
and called it by name should suddenly
destroy it, we would continue to behold
it in its own light so years after it had
ceased to exist. The very foundations
of knowledge dissipate before these vast
interstellar spaces, for we have no assur-
ance, even while gazing at the lilac
scintllations of the great Dog Star, that
king of Suns, as astronomers call it,
that it did not pass out of ex stence be-
fore we were born.
The telescope has rendered the valu-
able service of reducing the planets to
discs. When viewed with the naked
eye they are scintilIating points, some of
them brighter than the fixed stars, but
not otherwise different in appearance;
but when looked at through telescope,
their scintllations d sappear and they be-
come fiat surfaces ! Ike the moon. But
the fixed stars refuse to be reduced.
Sirius, the Dog Star, has always been an
object of interest to astronomers on ac-
count of its great size, its beauty and
brilliancy, and the changes in the color
of its light that have taken place since
ancient times. IL is estimated to b.
1,700 times as large as the central lumi-
nary of our system. 1t might be SUD