The morning news. [volume] (Savannah, Ga.) 1887-1900, 1891-05-08
THE sun TO SEE SPOTS.
a TRANSIT OF MERCURY 10 OC-
OUR TOMORROW AFTERNOON.

-
| Savannah Astronomers Preparing to
observe the Phenomenon The
Transit to Begin Little Before Sun
set and to Be Watched from Beau
neu-ProG Ashmore's Calculations
Ghs Value OF Careful Observations
Of the ccurrence.
Students Of astronomy are very much in
terested at present in the transit Of Mercury,
which, in this latitude, will begin shortly
before shutdown tomorrow afternoon.
By the transit of Mercury is meant It's
passage between the earth and the sun in
direct line with the view between those two
bodies, obscuring a small portion of the
suns surface, and having the appearance of
a small black spot moving across the face
Of the sun. The transit Of Mercury occurs
at intervals of IS, Z. 10, 8 and 10 years.
There is only one other planet which can be
in transit between the earth and sun, the
planet Venus, the orbits OF the two planets,
Mercury and Venus being within the earths
orbit.
VENTS LAST TRANSIT.
The last transit of Venus occurred in 1882,
and the one previous to that in 1874 The
next transit of Venus will occur in 1882 and
the one following ia 1890, the transits Of
Venus occurring in pairs, 100 and years
apart,
Venus being the larger planet, its transits
can be observed with much greater &C
curacy, and are consequently of greater
importance to the astronomers
The transit will be observed with great
care from the observatories of all the great
civilized nations of the earth.
Prot. Otis Ashmore, teacher Of natural
science at the high school. will observe the
phe lemenon Saturday afternoon from Col.
Olmsteads place at Beaulieu. Col Ohm
stead takes great interest in
the science of astronomy in which
he is well versed and possesses probably the
finest telescope in the state. Mr.. Ashmore,
Col Olmstead and probably Others will
view the transit through this telescope.
- PROF. AsHMoRE's CALCULATIONS.
Prof. Ashmore has made the following
calculations with regard to the phenomena:
Beginning of transit, or first contact, $50
o'clock p. m. city time; sunset 6:5S o'clock
p. m transit ends, or last contact, 11:28
o'clock p. m. This will allow twenty eight
minutes for observation OF the transit in
this latitude. On the Pacific coast the tran
sit can be observed for over two hours
longer, and on the islands of the Pacific
ocean the whole transit can be observed.
The planet will hardly be visible here to
the naked eye at the late hour Of transit,
but can be easily seen, provided the day is
not cloudy, through telescope or pair of
good opera glasses. The planet will appear
as black spot upon the surface Of the sun.
THE VALUE OF THE PHENOMENON.
The value OF the observation Of these
transits to the astronomical world is
that by means OF them they are
oht ad IN in ha
upon which they base their calculations
Of the distance Of the earth from the sun,
and which distance is in turn the linear
unit of all astronomical measurement. Two
astronomers making observations by oppo-
site sides OF the earth see the planet in
slightly different positions upon the surface
Of the sun and the difference in these posi-
tions enables them to obtain what Is known
as the solar parallex- The distance of the
earth from the sun is estimated TO be be-
tween 100000 miles and $4,000, 900, and
the astronomers are anxious to secure a
more accurate determination of this dis
tance
THE NEXT TRANSIT.
The next transit of Mercury will occur
Nov. 10, 1894, and the next after that on
Nov. 4, 1901. Ii the transits of Venus &C.
| Cured less rarely the transits Of the smaller
planet, Mercury, would be of less value.
unOlCuLJ 10 GLS Vi bLlo pLt DelUR
| only one-nineteenth the size of the earth
1t moves at the rate of thirty miles
second, and may we'll be compared to a
cannon ball in comparison with its
| flight across the surface of the sun.
Being some 81, O00,0 900 miles nearer the sun
| than the earth's distance from that body,
Mercury enjoys climate from five to ten
| times hotter than that of the earth When
the thermometer registers 500e in the shade
the inhabitant of Mercury puts on a bear
skin ovarcoat, or whatever substitute they
may have for that article in that distant
country. and shivers as he hurries along the
| streets
A CoLD.BLooDED PLANET.
| Only when the thermometer begins to
register somewhere in the neighborhood of
10000 in the shade does he begin to COM
plain of the heat and seek the Mercurial
| Tybee or Narragansett beach.
The year of the planet Mercury is eighty
eight Of our days, or about One-quarter Of
the earth's year. Schiparelli, the great
Italian astronomer, says that they have
only one day to the year, and his opinion is
generally received by astronomers as COR