Grant County herald. [volume] (Lancaster, Wis.) 1850-1968, 1874-07-02
The Transit of Venus.

The object of fitting ont govern
ment expeditions to various points in
the Southern Hemisphere to observe
the passage of Venus across the suns
disk, is partly explained in the follow
ing from an eminent authority:
"What is all this for? Not to de
termine mere question of scientific
inquiry; still less to crafty the astron-
omer's curiosity or to exalt his repu-
tation. The great object of the tran
| sit is to determine more accurately
than we ever have known the true
| distance of the sun from our little plan
ct. The issue of the observations will
probably be that we shall know the
distance within $4,000 miles of the
truth. We are a good way off from
this now, although the vast space has
been of late years reduced from the
95, 100000 to 100000 of miles; and
if any one asks further of hat real
use is this to the world, we answer
that the suns distance is for all astro.
nomical measurements of the heaven
ly bodies (and consequently of help
ing to determine for the mariner his
longitude at sea-; it is to him what
the chain is to the surveyor, or the
yard stick to the merchant. Until
we know the suns distance we can
not know his bulk or weight, or the
truth about the sun spots, the solar
| cyclones or currents, which certainly
affect our cyclones on land and sea-
We mast learn it more carefully in or
der to perfect the lunar and planetary
tables needed for navigation and for
the geographical position of places on
land as we'll as at sea. 1t is curious
to find at different periods in history
how far off the sun has been supposed
to be. The different estimates Of this
are strange landmarks in the slow
progress of time made by man toward
true knowledge of the heavenly bodies.
Herodotus says that the first dawn of
thought as regards the suns distance
made its appearance in his day. He
gives us to gather what these thoughts
were from the opinions of the earth
and the universe then generally held
by the learned Greeks. These were
that the earth was the chief body in
the universe; that it was but flat
plane, whose center was at Delphi;
that the sun was merely secondary,
uncertain and easily influenced body,
which moved about or over the earth,
but was itself acted on by the same
forces which we see acting around us,
but to so great an extent as to be
blown south during the winter by the
Etesian winds. Herodotus thought
this most probable. From this we
may fairly judge that the Egyptians,
WHOM ne cues, ana his OWN iU~...~1
Greeks, did not consider the sun to be
further off than ten miles from the
earth, for they did not consider the
winds at any greater distance.
"Not long after this, however, An
axagoras affirmed the real size of the
sun to be as large as the Peloponesus;
such a size, considered in referencet to
the SUMS now known angle, would in
dictate distance of IA 900 miles. A
century later, about B. @. $50, Arts.
tarchus, the astronomer of Samos, con-
Guided, by measurement of the moons
distance from the sun, that the sun
was at least 100000 miles off,
His plan was ingenious, but
his measurements were inaccurate;
yet the great Ptolemy, four centuries
later, adopted his determination, and,
combining it with the observations of
Hipparchus, computed the SUMS paral-
lax to be three minutes-twenty times
it's true value. Then, further down
Times stream, the famous old Kepler
made the suns distance to be 20,4O0,-
900 miles. The transit of 176l and
1869 put it up further to our late
school astronomy distance of 95,O00,-
900, and this, by rediscussion of the
observations of 1869 by Eneke, Stone
and Newcomb, has been again put
down to 81, 100000 miles"