The weekly democratic statesman. [volume] (Austin, Tex.) 1871-1883, 1882-12-07

had better make the best of the de-
of to-day. Scientific ex-
petitions have been fitted up by all
civilized nations to watch the transit,
and millions of money are being thus
An astronomical writer
explains that the telescope observa-
tions will consist in noting the times
D when the round dark ball of Venus
first makes a notch on the solar disk;
(2)when it shows itself as a completed
circle and the light of the sun first
glimmers across behind its moving
ball; (3) when it reaches the other side
and first joins its dark body to the
darkness around the sun, and "a when
its retreating form finally leaves the
disk. These four contacts" must be
very carefully watched, and their
times to the nearest second determined
The regular observers sent out by the
transit of Venus commission have all
been practised on an artificial transit,
which consists of round black disk
of tin, moving out from behind tin
partitions across bright background.
The disk moves by clock work, at
about the rate of the real Venus, and
many of the circumstances of the
motion are the same. There is the
same tremor of the light just before ii
shoots across at interval contact,
which renders any exact determine
tion of the time impossible, and the
same inability to see the notch the
first instant of its formation at exter-
nal contact. But the artificial transit
will not produce the effect of the real
planets atmosphere, and the "black
drop" a band of darkness which seems
to join the dark planet to the edge OF
the disk for several seconds after
ii appears wholly projected
on the sun, is not visible
Neither are the effects of diffraction
which make light body appear larger
than it really is. The first contact
will be at about 9.02 a. M; the second
about 1923; the third about 800 p. m.
and the fourth about 3.21. Venus
cannot be seen as she approaches the
disk of the sun, unless possibly faint
ring of light, due to the refraction OF
her atmosphere, shall make her outline
visible. When she is partly projected
on the disc, thread of light around
her can doubtless be seen, owing to
this cause. The first intimation of
her coming.will probably be theround
notch cut from the disc of the sun.
This notch will appear at a point 147
degrees from the north point of the sun,
around by way of the east.
Those who cannot command the use
of telescope may see through a
piece of smoked glass the dark round
mass of the planet entering on the
southeast and passing off on the
southwest limb of the sun. But the
main reliance of the American astron-
omers is on the photographs of the
sun with Venus ON it, which will be
taken during the transit. 1t is prob
able that each of the eight parties sent
out by the commission will secure
about two hundred photographs.
These are taken at the focus of lens
about eight inches in diameter, set
vertically. The sun is reflected
through this lens by heliostat of I'M
silvered glass. The image of the
sun thus formed forty feet
from the lens is four inches in
diameter. The part of the light
after passing through the lens is
covered with a wooden roof to cut
out side light. The arrangement is in
reality fixed telescope, in which the
eye piece is dispensed with, and the
tube is the wooden roof. The hell
ostat moves by clock work, which
causes it to keep the sun reflected
through the lens. In front of the
sensitive plate is a glass covered with
a reticule, which is photographed on
the sun to detect any sliding of the
film. A plumb line is also photo
graphed so that the vertical of the
picture is correctly known. The scale
is ascertained when the distance be
tween the lens and the sensitive plate
is definitely known, and distortion is
guarded against by the accuracy Of
the curvature of the lens, and the &C
curacy of the flatness of the
mirror. The transit will be widely
observed. The $4,000 which congress
appropriated will put in the field eight
parties, which are stationed respec
lively at Cape of Good Hope, New
Zealand, Santiago, Patagonia, New
Mexico, Texas, Florida and Washing
ton. The English, French and Ger
man governments also send out ;
number of parties. Besides these
there will be many observations O.
contact and some photographs obtain
ed at the various observatories of tn,
United States. 1t is hardly possible
that clouds will interfere at all tn,
stations, widely separated as they are
But will the results of 1882 be an,
gain over those of previous tran
sitsp The observations of 1861 ant
1869 show such a wide discrepanc,
that they did not make us certain a
to the distance of the sun within
about four million miles. The Eng
lish observations of contracts in 1877
narrow this down to III million. Blu
this is wide margin. So difficult
is to compare observations made unde
different circumstances of atmospher
and instruments, so diverse are tn
phenomena seen and so various ar
the times recorded for them, that it j
hardly likely that the most favorabl
results win do more than diminish tn
uncertainty.
HOW THEY PROPOSE TO DECEIVE
Federal aid in the abolition of illii
eracy is to be urged by some of tn
southern members of the next cor
gress, and the Republican organs ar
insisting that such a measure shoul