Iowa County democrat. [volume] (Mineral Point, Wis.) 1877-1938, 1882-12-08
q. W i. 1T INVFS T
Dodgeville, Wis, Dec. 2.

before the city high school. 1t is in
serted in this column by request.
The Introductory headings were
placed upon the board to be used
as an aid to both the speaker and
the listeners. The exercise was
followed in this, as in other cases,
by questions designed to test the
amount of attention bestowed by
the school, and to add to the in
formation already given:
l. Venus the second planet from the sun.
H. When morning and when evening star,
III. Its distance from the sun.
". Its diameter, day, and year.
V. When first seen an evening star.
VI. Transits-when they occur, and for what
employed.
VII. What planets can present this phe-
nomenon.
VIII. What station observers take
TX. When the first transit was seen.
X. Transits of 1851 1862 1874 and 1882.
NJ. When the next viii occur.
Venus, the second planet in order
from the sun, is nearest to the earth,
and on that account appears to be
the largest and most beautiful of all
the planets. By reason of its great
brilliancy it may sometimes be seen
in the daytime with the naked
eye. During a part of the year it
rises before the sun, and it is then
called the morning star; during
another part of the year it rises
after the sun, and it is then called
the evening star. 1t never appears
to recede farther than At degrees
from the sun, or about half the
distance from the horizon to the
zenith. Its diameter is 1910 miles,
its rotation period, % hr. 81 min.
% Sec, and its year ga days. When
it is first seen as an evening star it
appears very near the horizon, but
on each succeeding day it rises to a
higher elevation and continues a
longer time above the horizon. Thus
it appears TO move eastward from
the sun till it reaches the point Of
its greatest elongation when it APP
pears for some time stationary; after
which it commences a retrograde
motion from east to west, and soon
disappears. About eight or ten
days after it has disappeared in the
evening, if we look at the eastern
sky in the morning a little before
sunrise, we shall see a bright star
near the horizon which was not
previously to be seen in that quar-
ter; this is the planet Venus which
has moved to the westward CT the
sun to make its appearance as the
morning star.
A transit is the passage of a
planet across the disc of the sun.
Mercury and Venus are the only
planets having orbits within the
earth's orbit and hence the only
ones that can present this phe-
nomennn. At the time of its near
est approach to the earth Venus is
invisible to Us, unless transit oc-
ours, when it is seen on the disc
of the sun in the form Of a black
spot. This spot is too small to be
seen by the naked eye, and for
this reason the transit was never
observed by any ancient astron-
omer. The transit is employed for
the determination of the suns dis
lance; it reeurs at alternate inter
walls of eight and one hundred and
Ave, and eight and one hundred
and Twelve years.
In general it is necessary for
the observers of the transits to seek
for one station in high southern,
and another in high northern lat
itIde.
The earliest transit of the suns
disc of which we have any account
is that of Venus in 1859. In 1761
and 1869 observations were made,
but with widely different results.
Much attention was attracted to
the transit of Dec Sth, 1874. The
results obtained were excellent.