The White Pine news. [volume] (Treasure City, Nev.) 1868-1906, 1882-12-02
THE TRANSIT OF VENUS.
An Interesting Event Which Occurs
Next Wednesday.
TFrom The Scientific American ]

fFrom the Scientific Americana
One Of the greatest astr onomical
epochs OF the century will occur on
Wednesday, the 9th of December
The planet Venus will then make her
way across the suns disk, aud Amer
lean observers are this time on the
ri 1ht side OF the earth To behold the
rare phenomenon. The actual sight
OF the transit, except for its bearing
on science, possesses no special in
terest. II is not a glorious spectacle,
like total solar eclipse, nor wierd
combination OF celestial beauty, like a
total lunar eclipse, nor an awe-inspir-
ing exhibition OF omnipotent power,
like n graad aurora, nor startling
display Of celestial pyrotechnics, like
a downfall OF meteors, nor a sudden
apparition Of a great comet sweeping
the skies with its gossamer tail.
A tiny black spot will cut sharply
into the suns border, move slowly
over his disk, and, after a passage OF
nearly six hours, viii suddenly dis
appear. This - all that viii be per-
eeptible to the naked-eYe observer.
But to the astronomer and the tole-
scopist the event Il full OF The deepest
Significance. Through its instru
mentality "A solution i sought of one
OF the noblest problems ever claDo-
rated 10y the highest exercise OF hu-
man reason. To measure the unap-
proachable, is the point at is-ue, and
never, IN any previous combat with
inmensity, bave astronomers had at
their command such resources for be-
coming yIctors in the contest. The
labor demanded II of the most severe
and delicate nature, even when as
sisted by the most perfect instruments
that have been invented. The utmost
accuracy is required, or the result will
be failure. Measurements must be
accumulated like grains OF sand upon
the seashore. Thousands Of obscrva-
tions are often required IN correcting
an infinitesImal error. The grand
OBJECT for which nearly one hundred
transit expeditions have been organ
lied, is to acquire tue right OF adding
or subtracting | SIS than one-tenth Of
a second 10 the solar parllex, from
which the suns distance from the
earth is deduced.
II isa work OF exceeding difficulty
to determine the parallax OF the sun,
on account Of its minnteness. The
problem has not yet been accurately
solved, after the incalculable labor
bestowed upon it, the suns distance
is far from being . certainty. The
best authorities give the parallaN As
less than o., almost certainly between
s:75" aud $50. But this tenth of a
second that is considered doubtful, is
more than hHndredth part OF the
whole, although, says Professor
Young, it is no more than the angle
'subtended by single hair at a dis
lance of 500 feet. Ii We accept $3.50"
as parllaX, an estimate probably
nearer the truth than any osher, the
suns distance, expressed IN miles,
will be 2,SS5, 600, while the variation
of netWentieth OF "a second will
change the result either way "a half
million miles, The most sanguine
observers will feel that they have ac-
complished all they expect if the un-
certainty is reduced TO quarter of a
million miles.
II eyes were perfect and instru-
ments were perfect, there would still
be- great difficulty in obtaining the
exact pamllax OF the sun, but the
problem is complicated by the im-
perfection OF human vision and the
iihperfection of astronomical instru-
ments. Three methods of observa-
etion are employed by transit observ-
ers: the direct observation ofcontacts,
the micrometric method, and the
photographic method, which all
have their special advocates. The
direct observation of ingress and
egress is the most simple, and is chief
~ relied on by English and some
French astronomers. II needs only
n good telescope, two eyes that know