Savannah morning news. [volume] (Savannah) 1868-1887, 1882-08-25
THE COMING TRANSIT OF VENUS.
The United states Expeditions which
Will Take observations.
Washinoton star

Washington Star.
The transit of the planet Venus across tht
face OF the sun occurs on the 9th of Decem-
Der next, and the scientific world is looking
forward to that event with great interest
In every civilized country preparations are
being made to observe the transit, and the
various civilized governments have made
liberal appropriations to send out parties Of
observers to various points. The United
rest OF the world in this respect
Congress having appropriated $4,000
for this purpose. It is the intention of the
authorities to equip eight parties, and as those
intended for distant parts of the earth will
have to start In the early part of the next
month, the preparations are now under full
headwsy at the Naval Observatory. The
same method employed in observing the
transit of 1874, by means Of photographs of
the suns surface, will be followed next De-
cember, and It is believed that the results
will justify the wisdom of this selection.
Besides the four stations in this country,
which will be at Washington, Cedar Keys,
Fla, San Antonio, Texas, and Fort Thorne
New Mexico, there will be four foreign
stations, namely, Cape of Good Hope, Santa
Cruz. Patagonia, Santiago, Chill, and enc in
New Zealand.
The party for the New Zealand station
will start out first, and expect to leave about
the 1st 0f September. 1t will be In charge
of Mr.. Edwin Smith, of the United States
Coast Survey, who has for an assistant Prof
Prltchett. of Washington University, st.
Louis. The party for Patagonia will leave
about the same time, and will be stationed
near the mouth of the Chico river. Lieut..
s. W. Very. United States Navy. will be in
charge Of this party, with Mr.. o. B. Wheeler
as assistant, and Mr.. William Bell, of Phila.
delphia, as principal photographer, and Mr..
Irbin Stanley, OF Carmel, Ind, as assistant
photographer.
In order that the arrangements for OBJ
serving the transit may go off without
hitch, the members of the parties have been
devoting some time at the Naval Observatory
to practice. An apparatus, similar to that
which will be employed at all the stations,
has been erected at the observatory, and the
practice IN photographing the sun has been
made familiar to all those who are members
OF the parties. This apparatus consists of
long shed, having at one end Photographic
lense and hellostat, which turns the rays
OF the sun and throws them horizontally
into frame house at the other end of the
shed, where the photograph is made With
the exception Of this apparatus, which is
very simple, and It is to be erected by the
parties upon their arrival at their destiDa-
tton, no equipment of instruments is needed.
small equatorial telescope will be taken
along to observe The contacts-5he begin
ming and the end Of the transit.
The two other parties for foreign stations
will start about the middle OF September
The one going to Santiago, Chill, will be in
charge of Prof. Lewis Boss of the Dudley
Observatory, Albany, N. Y. MIR. Miles
Rock, Of the Naval Observatory. will be
assistant astronomer, and Mr.. T. Marceau. of
Canandaigua, N. Y, chief photographer,
and Mr.. Gustav Theilkuhl, of this city,
assistant photographer. The other party,
under the charge Of Prof. Simon Newcom6,
the Superintendent of the "Nautical Alma
nae" will go 70 the Cape OF Good Hope.
Lieut. Thos. l. Casey, Jr, United States
Army, Will be assistant astronomer; Julius
Ulke. OF this city, principal photographer,
and E1sign Holcomb, United States NAVY,
assistant photographer.
The parties for the stations in the Upited
States will not start until the middle of Oc-
tober, and the personnel has not been agreed
upon as vet. Professor Hall will have
charge of the party at San Antonio, Texas;
Professor Eastman at Cedar Keys, Fla;
Professor Davidson at Fort Thorn, New
Mexico, and Professor Hardness the one In
this city. The parties that were sent out in
1874 to observe the transit of Venus had ia
many cases rather rough experiences, owing
to the wild and desolate localities in which
they were stationed. This year all the par
O.
near large cities, with the exception of the
Patagonian party. The latter, however,
will be conveyed to the station on the United
States steamer Brooklyn, which will remain
with them until their work is completed.
While there is great interest manifested in
the results Of these observations, and con
siderable enthusiasm in scientific circles,
still the chances OF the entire preparation
coming to nothing are so great that scen-
tifc men are not inclined to be verv sar-
guine. The transit of 1874 was rendered
valueless on account of the clouds which
obscured the face of the sun during the
transit and prevented photographs from be-
ing taken. A more favorable condition is
hoped for this time. In order to avoid as
Tar as possible the unhappy contingency OF
clouds, stations have been selected in the
South instead of in the North-W Washing
ton being the furthest Northern station.
The question might be asked by the unscien-
tiic mind why so much interest is
attached to this phenomenon. Transits.
eclipses, and other phenomena are
continually occurring without any
particular interest being attached to them,
The reason is that Venus affords the best
means of mastering problem which is one
Oh the most important within the whole
range of astronomY-the distance of the sun
from the earth. As the orbit of Venus is
nearly on the same plane as the esrth's
orbit, 1t happens from time to time that II
passes between the sun and the earth, and
appears like q black spot crossing the
luminous disk. This passage occupies
several hours, and takes place at intervals
OF years, then 11318 years, 8 years. and
11311 years, and so on. The last passage
occurred in 1874, and the one following this
years will not occur until the end Of 122
years, or in 20O4. Two observers, situated
in the stations most distant from
each other, note the two points where the
planet, seen from each CT their stations.
seems to be projected at the same moment
in the solar disk. This measure gives the
angle formed by the two lines starting from
the stations and crossing each other on
Venus and passing on to the sun. It is the
measure OF this angle, made by observers
placed on all parts Of the globe, which gives
what is named the parallax Of the sun. The
determination of the solar parallax. there
fore, is the object of these Expeditions.
Another object to be attained is the accu.
rate position OF Venus in reference to the
centre OF the sun, and also the measure of
the diameter of Venus in the SUMS iisk.
The inaccuracy in the present estimate of
the distance OF the sun from the earth Is. &C
cording to Prof. Hall, about 500, 700 miles.
BY the use OF the Photographic method,
which Prof. Hall considers far superior to |
any other, he hopes that the data will be
obtained which will determine within a |
small fraction OF a second the solar paral- |
lax. The foreign governments, as stated |
above, have very generally decided to send |
out parties to observe the transit. The |
French will send an expedition to Santa
Cruz, Patagonia, and will also have stations |
in Florida. The Belgians will lave one sta |
tion in San Antonio, Texas, and another at
Santiago, Chill. The Germans will have
two stations In Santa Cruz, one at Hartford.
Conn, and one at Aiken. 8. g. The English |
will have one at Cape of Good Hope and one
on the Island OF Madagascar, New Zealand,
and Australia. The English southern sta
tions will be in the West Indies.
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