Alpena weekly argus. [volume] (Alpena, Mich.) 1871-1893, 1882-12-20
Transits OF Venus.

servations Of only four transits of
Venus; those of 1889, 1761, 1869,
and 1874. Kepler was the first as
tronomer to predict that a transit
would occur in 1881. But it passed
unobserved, and his tables were so in
accurate that he failed to detect the
transit that would take place in
1879. This too would have passed
unobserved had it not been for the
enterprise and enthusiasm of young
Englishman, the curate Of church
in the north of England. jeremiah
Eorrox, though only eighteen years
of age, had mastered all known as
Economical problems. He discovered
that Kepler's tables indicated a near
approach Of a transit of Venus. The
hope that he might witness the Won
derful sight took possession Of his
Imagination, and day and night he
studied the tables of Kepler until he
discovered an inaccuracy in the cal
culations. He worked out table for
himself, and predicted a transit for
1889. He revealed the secret to an
intimate friend, and they, keeping
their own counsel, patiently waited
for the advent of the time that would
verify the prediction. At last the
great day arrived. 1t was Sunday
and bright, and cool, and clear. The
young astronomer sat in darkened
room, with the suns image reflected
through a small telescope upon a
white screen, over which the planet
must pass as a round, dark spot if his
calculations were correct.
Such was his extreme conscientious,
that he left his watch when the church
bell rang, to fulfill what he consider
ed higher duty. But his patient
labor was rewarded. On his return
from service, he discovered on the lu-
minous image of the sun, the tiny
black sphere that marked the passage
of Venus across his disk, and thus
won the honor of being the observer
of the first transit ever seen by NOR
tai eye.
A new interest was now reused in
astronomy by the report of the great
event. During the interval between
this and the next transit of 1861,
science had made rapid progress
Transits of Venus were, however, con-
sidered only as astronomical curiosi-
ties, until in 1877, HALEY, while OBJ
serving transit of Mercury, discov-
cred their scientific import as means
of determining the suns distance.
Extensive preparations were made
in prospect of the transits of 1851
and 1869. That Of 1861 was visible
in Europe, and was watched by near
ly two hundred observers, but the re.
suits were unimportant. That OF
1869 was more extensively observed
but the instruments of those days
were far from being accurate. When
the astronomers returned from dis
tant lands with the results of their
labor, and proceeded to make com
parisons in order to deduce the suns
parallax, great discordance was found
in the measurements Of the different
observers. More than half a century
elapsed before the results were work.
ed up in satisfactory manner. This
was done by Encke in 1924, and S57
was fixed as the solar parallax, cor
responding to about 95,0OO,00O miles
This distance of the sun was for many
years accepted by astronomers, and
adopted by all works on astronomy.
1t is now well known that the par
allax was too small, and the distance
too great, including an error of near
ly 100000 miles.
The world wide interest taken in
the transit of 1874 and its extensive
observance is matter too near the
present transit to have become mat
ter of history. The work of reduc-
ing the observations has not yet
reached final result, for an immense
amount of calculations and much
tedious investigation are involved.
The indications are, from portions of
the work accomplished, that the suns
parallax lies somewhere between $40
and SS3. The sole purpose which the
transit expeditions of 1882 are sent
to the most available localities for
witnessing the phenomenon is to de-
termine more accurately this most inn
portant base line of celestial measure
ment. The whole scientific world
will watch for the result, while ap-
proximation, not certainty, is all that
is anticipated.- Scientific American.