New-York tribune., 1901-02-10
n OBSERVE THE ECLIPSE.
-ur NAVAL OBSERVATORY SENDS AN
EXPEDITION TO SUAiATRA.

,,-.ssinrton Feb. 2 CspeciaD.-Before last
ne Naval Observatory had not oficiaIly
60 an eclipse OF the sun since 1875. al
-, the foreign observatories OF national
-ac-er have sent so many expeditions 70 dis
-, lands that scarcely a total eclipse has been
,-sss bv European astronomers. England
,-,,,rb SIS Government institutions and scien-
-, associations, has taken the lead IN sending
~ sueh expeditions and her men-of-var have
s-.-rantlv been called into service TO carry her
,s.-onomers 10 inaccessible places, so that for
=. last forty years few eclipses have escaped
careful observation.
r-rzar its present astronomical director. Pro-
,.ssor : 7 Brown, the Naval Observatory has
-asa q new departure in this direction, and last
year members Of its staff were sent South TO
observa the eclipse This year an appropriation
-, Congress Of a liberal sum for the observa-
-, n The eclipse in Surnatra which will occur
i, Nav Is has enabled the director 10 at out
= exoedition for this eclipse. The expedition is
!, charge Of Professor A. y. Skinner, and start
~ from Washington On Thursday. Its person.
Il includes Professor W. s. Eichelberger. AS
s,s,snt Astronomer F. B. Litteu. and c. H
r,.-.-s I E Jewell and W. W. Dnwiddie. Of
-. Crsa-,arorv staff. Professor Barnard. OF the
z,.-pas Observatory; DR.. W. ]. Humphreys, OF
-. r--,versitv of Virginia; DR.. s. A. Mitchell,
i rolYnabia University, and DR.. H. D. Curtis.
s,a~lv of the Lick Observatory, now an as
.-.arr IN The Leander Mccormick Observatory.
-rz-,,,qb the courtesy OF the War Department
r. Marty will be carried in the transport Sheri-
-, sailing from san Francisco on February 10
- Manila where q man-of-var from the Asiatic
ess- will be set apart 10 convey the expedition
. psssrE in the island Of Sunatra, and back
-.,D when SIS work is finished 70 Manila II
80, ~ the officers and men OF the naval vessel.
81 has been impossible 10 provide the neces-
-. personnel for carrying out the numerous
lines If work which viii be undertaken.
The expedition viii reach Manila by the mid
Ale ~ March and Padang by the first Of April
leaving nearly two months for the field opera
,ions in suuatra- The programme OF work
contenaplates photographic, spectroscopie and
,olariscopie observation, in addition 70 the
rzual visual work.
In the Photographic field Professor Barnard
,,u he situated near the central line, probably
st solok where he will photograph the corona
m large scale using the lens OF 6l.5 feet focus
which he 50 successfully employed in the last
sclipse at Wadesboro. Besides this, he Will utll-
ize some smaller apparatus.
Near the northern border Of the shadow path.
~ Fort de Kock. Mr.. Peters viii operate one Of
The 40-foot photoheHograph lenses OF the Naval
observatory. two Of which gave fine results al
the last eclipse at Barnesville ana Wadesooro
Two other Photographic instruments are being
taken out to test further the value Of photo
erspblng with visual lenses, using some form
n screen to cut OF the violet light. The results
AZ GAINESVILLE IN the last eclipse show that this
method FOR the study Of the greatest extension
n the corona is OF great value.
The spectroscoplc Investigations. as IN the last
eclipse viii be carried on almost entirely by
gratings cnncave and fat. One OF these, near
the northern border which VII! be IN the hanos
of Or. Humphreys, has Just been constructed
st Johns Hopkins University. II IS a concaNe
grating OF 80 feet focal length, and ruled
space Of 1 by inches. II viii be used without
slit and the employment OF such a powerful
gra-ing near the northern border, where the ou-
ration OF visibility OF the reversing layer viii be
several seconds. IS expected 20 yield results OF
unusual value. The character Of the coming
eclipse is indicated by the fact that although
this station viii be within seven miles Of the
northern border, the duration OF totally Is over
three minutes more than twice long as the
duration Of totality az the central line OF the
eclipse OF 1900.
Dr. s A Mitchell the objective grating which
was SO successfully used az the last eclipse
Another objective grating with long slit viii
also be employed. With this II is expected 70
Obtain some light On the rotation OF the corona.
as the length OF the slit is sufficient 10 take in
the disk Of the moon and the brighter portions
q the corona Mr.. Littel viii have this instru-
menr in charge
The assignment Of all the instruments has
nnt been determined as n viii depend upon the
number Of stations occupied. The difficulties Of
travel and transportation in Sumatra are an IN
known quantity, and the selection OF stations
has been made only in a preliminary way.
The duration Of totality in the island OF Su-
matra Is six and half minutes. There have
been during the century one two eclipses
when the duration OF totality has been longer.
hut these, owing 70 the unfortunate ha bit Of
past eclipses OF selecting an ocean or some other
inaccessible place for their rare exhibits have
not been observed. The prospect OF favorable
weather In Sumatra is good although il at
hrst assumed that the conditions were SO un-
favorable that il would not be worth while for
observers 10 make the long journey. The
meteorological society OF Batavia has for years
KEPT records Of temperature and rainfall in the
Island, and special observations were made last
year during the months Of April. MAY and June
covering the region that will be traversed by
ne eclipse party. Although at Solok the place
selected for the principal station, there was rain
On nineteen days in May, the sun was visible on
tnlrty-one days from the hour Of 10 70 o'clock
ne rain evidently occurring IN the afternoon
ara night, which makes the scientists who will
- A1I way round the world in the interest Of
astronomy, hopeful that like conditions may be
und this year.
me track Of the eclipse crosses Sunnatra Bor-
-. \ NeR-Lealand and number Of smaller isl
----s- In ne map shows however. that the greater
10il ~ y IS over the Indian and Pacific oceans