New-York tribune. [volume] (New York [N.Y.]) 1866-1924, 1883-04-16
THE COMING SOLAR ECLIPSE.
PREPARATIONS FOR OBSERVING 1T.

PREPARATIONS FOR OBSERVING 1T.
pr. Ns or THE UNITED STATES EXPEDITION IN TUE
SOUTH PAcIFIc-TnE INSTRUMENTS To BE USED
PROPOSED WORK or THE ENGLISH AND FRENCH
EXPEDITIONS.
FRoN SPECIAL CORRESPONDENT OF THE TRiBuNk.I
CALLAo, Peru. March 20.-The party which
sailed from New-York on March to observe the solar
eclipse Of May from Caroline island In the soutn
Pacific arrived at this port to-day having made RAPID
run and close connections at Panama the OHteu
States man-of-war Hartford, which Is TO receive the
party ready for and viii sail on Narch ~ expect
ing to make passage of $500 miles in about twenty
Ave days possibly touching at the Marquesas Islands
After the eclipse tho Hartford ~ convey the party 10
Honolulu from which place they Will proceed to San,
Francisco The members OF the expedition are Pro-
lessor f. g. Holden. OF Washburn Observatory, Madison,
Wis, who is chief of the party; Mr. C. H. rockwell vi
Tarrytown n. Y. through whose personal efforts the
expedition planned; Dr. @. 3. Hastings, OF johns
Hopkins University, Baltimore; Mr.. f. d. Preston OF
the United States Coast Survey; Ensign j. Brown OF
tine United States Naval Observatory, and Mr. W.
UPTON OF the United States Signal Service. Two Eng
lIsh scientific gentlemen, Messrs II. A. Lawrance am
c. Ray Woods, Of South kensngton Joined the parry a,
Panama. The American expedition was planned by the
National Academy Of Sciences and Is under the charge oi
committee OF which Professor c. A. Young OF Prince
ton is chairman and Professor II. G. Coffin, OF Wash
ington secretary. The English members are sent by
the Royal Society and the Committee on Solar Physics
esI eciay Photographic work. They are engaged
in spectroscopic work with Mr.. Lockyer and were both
members OF the English expedition which observed the
eclipse of last May at Sohag, Upper Egypt
The programme OF work planned for the eclipse EN-
braces o variety OF observations chief Of which are those
with spectroscope The instrumental outfit large
that OF the American members being contained In sixty
two boxes and that of the English members In twenty
eight the majority OF them containing apparatus but
few devoted TO the requirements OF camp lie upon the
island There seven telescopes mounted eqratoi-
ally having apertures respectively OF 64 q, l-lo H.
3Ia and two of zig inches diameter. The 6A ineh
equatorial is provided with grating spectroscope to be
used in examination of the cbronOsphere before and
after toaity. and during the total phase the erating
will be exchanged for large prism for the study OF the
corona The o inch will used by Professor Holden
TO search for intramercura planets AS was done by
Professor Watson and Others in 1873 the results being
not decisive The 10 inch ia providedwth grating
specroscope and is to be used in studying the relative
lengths OF lines reversed just before totality within
small region OF the spectrum. The grating can De ex-
changed a single 800 prism with which to study the
limits to which the line l474 can be traced. One OF
the zig inch telescopes is provided with large 800
prism OF flint glass placed before the objective and Is
designed for observing the relative heights and bright
ness OF certain spectrum rings A simple migrating
specroscope unattached to ateescope will also be used
for observing the character OF the lines visible during
totaty OF the other telescopes one Is furnished with
sayart poarseope designed to show the character OF
the corona polarization aud tie others will be available
observing the times Of contact and for studies OF the
shape and structure Of the corona.
The plans OF the English eDbers embrace an extern
sye series OF spectroscopic and Photographic work com
bined. beam of light will be thrown by siderostat
upon four spectroscopes: integrating, anayzng and
prsmatic spectroscopes and a Rowland grating. the
plate of the named will he driven by cock-work, In
that's the n
slant is small the integrated effects that have previously
been observed may be differentiated The Rowiand
grating provided with two cameras each TO be used
upon definite portions Of the spectrum The analyznS
and prismac spectroscOpes were used with success at
the Egypt eclipse. Red-end plates will be used with
bnth these Instruments IN order II possible to photo
graph lines rings IN the red as wei as the volet
portions OIL the @ vo ~ inch obiectiyes provided
with spectroscopcs and cameras The first Is grating
Tf Spd second orders Of spectra fhc second is
specroscope low dispersion Among the interesting
some spectrum observations by Mr. Lockyer. He saw
the short bright chromospheric lines usually FOUND IN
protuberSnces, ten minutes before totally, ana Just
before totally observed the lines which are usually
thickened spots Hendng as iaDt llheg 10 a
much greater elevation than the protuDeIshce lhes.
The attempt is 10 made by the instruments upon the
equatorial stand mentioned above to repeat these obser-
Th nbo ogrpls are to be used, to attempt TO pho
tograph inner details OF the corona when mas never
vet been done; the 0htr LOT pnotogIaPne INC
porou OF the corona TO its furtiest extent ODserVa.
and meteorological instruments ana
of phenomena are also To be made, as well
"A the careful determination OF the latitude and lOnS-
tude of the island , -, .
Th limited States Coast Survey improves the oppOru-
nfy 10 make pendulum observations at the island and
1 AT the Sandwich Islands and San Francisco on the
return II is by observations with pendulum made at
derrnt portions of the earth that the problem OF the
tne shape OF planet Is solved in the most refined
-. H. l.
70 lee located in the South Pacific IL Is under French
onsulces and includes among lis number the physst NJ
JANSEN This party is to journey TO me lsthmus at
Panama ana from that point he conveyed by the man
ofwnr /, Eclaireur. Their destination is also Caroline
Tand but il Is probable That either the American or the
French party will locate at Flint Island. which Is also
I'm the path OF toaty order that both Islands may be
the event OF cloudy weather at one sta
non fine other might be favored with clear weather
The eclipse is OF long totally the duration OF the
total phase being between five and six minutes the
Greatest duration possible, hen the sun and moon
most ayorably situated, being seven minutes The path
NJ otality lies wholly in the Pacific and It Is only upon
few small islands that any one can gain fo0thod aud
room for his The two islands Caroline ana
Film are approximately in latitude lO' south and ong
tnde 5O0 west They coral reefs, containing cocoa
mn trees and other growth few Inhabitants have
ved there in years bat II Il not known definitely
whether any are the Islands at the present time.
NV. from the eclipse parties he expected about
,ie taddle of June With avoring weather the extern
siye preparations made should bring valuable scendhc