The silver state. [volume] (Unionville, Nev.) 1870-1903, 1886-06-23
QUE DISTANCE FROM 1HE SUN.
increncc In the Calculations or Various
Astronomers.
Edinburgh Review.l

Edinburgh Review.l
The grand views of magnitudes which
arise in connection with the considera-
tion Of the physical condition of the sun
are. as a matter Of course, all dependent
upon the measures that have been made
of its distance. Because the solar sphere
has the apparent sizs Of foot bali held
Jos feet away, it must therefore he about
500, 900 miles across if : be los times
$50, 600 or 93, 100000 m. away; that Is
in a familiar form. the , tionale OF the
process by WHICH the ids. of its maeni-
tude has been acquired. Miss Clerke
relates very fully and cbarmiugly TIE
history of the labors which have been de-
voted by scientific men to attain exact
accuracy in this fundamental particular.
SO much the greater pains have been
taken in the matter because the distance
of the sun is unavoidably the unit of the
measure which has to be employed IN
making all further Investigations as to
the profundity of space. The semi dl-
ameter of the earth's sphere is necessarily
the fundamental unit in astronomical
surveys; aud auy error in its determine
tion is multiplied in an infinity of ways
airy and stellar distances. But the meas.
IRE which has to he accomplished in com
ing to the solution of this problem in the
most direct way is about the same thing
as taking the apparent size Of half
penny when held 1000 feet from the eye.
This is the amount which is known as
the horizontal paralIax of the sun; that
is, the difference of the position which
the sun holds in the vast field of space
among the stars according as it is viewed
from one or the other extremity OF the
half diameter of the earth. The transits
Of Venus have been employed as indirect
means OF getting at this measure through
the intervening stages of mathematical
calculations, since the first introduction
of the method by Horrocks in 1851.
During the last two transits of Venus
those namely, which occurred in 1874
aud 1882 the most strenuous efforts
were IN ade by the astronomers OF all civ
ilzed nations to get as exact a measure
as was possible. In 1874 eighty distinct
stations, scattered over the most suitable
portions of the earth were established at
an expenditure OF nearly quarter OF
million Of money But the result is that
this method so long cherished as the Ia
vorite of astronomers. is now found to
have failed them. 1t is universally adj
mitted by all that the sun is considerably
nearer to the earth than it was conceived
to he few years since. But, so far as
the transit observations are concerned,
Mr.. Stone gives 80, 800, 600 miles as the
corrected distance derived from the oh
sercations Of 1874 M Fave gives 93,
$50, 900 miles; Professor -Yonng 92 ,SS5, 4
600, and Doctor Ball 93 900 900. Doe
tors. therefore. disagree in this matter
very materially From the transit OH
servstiens OF 1882 the probable error was
held nv Professor Houzean. the late Di-
rector of the Brussels Observatory. who
devoted great labor ard care to the re
duction and comparison Of the calcu'a-
tions. to amount to 900. 900 either wav.
or to a total uncertainty of 1900 600
miles. By common consent of the best
authorities the possible error in the meas.
ure OF the suns distance by this method
of observing ia held 70 he not less certain.
iy than l, 500. 600 miles.