The New York herald. [volume] (New York [N.Y.]) 1840-1920, 1875-03-05
THE ECLIPSE.
Best Opportunity for Sun Study to
Occur this Century.
Time and Track Of the Suns
Total Observation.
DIAGRAMS EXPLAINED.
The Ross-Red Chromosphere and
the Corona.
SOLAR CHEMISTRY.
The SUMS Fiery Meteors and
Meteorology.
ECLIPSE EXPEDITIONS AND PREPARATIONS.
Tho Novel instrument for Attacking the
Great Solar Problem.
The SUMS Fiery Meteors and
Meteorology.
ECLIPSE EXPEDITIONS AND PREPARATIONS.
The Novel Instrument for Attacking the
Great Solar Problem.
A Foreglirnpse OF the Earth's
"Dies Tree"

The present year will be memorable in the an.
nails OF astronomy. Besides the great transit OF
Venus the phenomenon OF total solar eclipse
probably the most favorable that can take place
during this censury-are among the celestial
events toward winch scientific attention has been
eagerly directed. There are many grave problems
OF solar physics which, from time immemorlal
have been unoer discussion, that can ind solution
only IN speclroscoplc examination Of the eclipsed
sun: Although the coming eclipse is not so rare
aud 50 exciting an occurrence as the recent tran.
Sit there are peculiar circumstances which invest
1t with unusual interest and importance.
One OF these Is the fact that 1t Will be observable
only ar q small number Of land stations and these
lie mostly in the Indo-C Chinese peninsula, within
the little Kingdom Of Slam. In this ancient ma
sionahty court astrologers ana prognosticators
have been long employed at trivial remuneration,
and formerly were severely castigated on the fall.
nre OF their predictions. By the toughest and
crudesr methods the Siamese astronomers.royal
have been in the habit Of calculating eclipsea
Anc to them, we may well imagine. the greater
scientific perfection Of their European brethren.
coming in their midst with the most magnificent
and modern machinery of the star gazer will be
An event moro impressive than the eclipse ITSELF
Although the phenomenon soon TO be observed Is
now among civilized nations one Of scientific in.
terest rather than popular terror; It has by no
means losttts influence on the uneducated masses
Of men. Before astronomy had made known the
cause OF eclipses, their occurrence was regarded
a. indicating fearful deviatious from the ordinary
course Of nature. In the nrst year Of the Pelopon
nesian war, whom the Athenian neet was ready to
sail, q solar eclipse would have demoralized his
men and marred his expedition, had not Perlcles
lts commander, been abe to explain the mystery
eighteen years later an army composed mainly OF
she same highly cultured and Intellectual Athe.
MAN element. was lost from failing to move, at .
critical moment. because terrified by An unex.
planned lunar eclipse. History has preserved
the instructive incident OF how Columbus,
sorely pressed by famine, relieved his wants
and secured the fruits OF his celebrated
voyage by threatening the Indians that tho
moon, then riding in serene majesty through che
heavens, would be darkened on q certain day II
they did not succor him. But while the alarm
now excited by ecipses 10 confined to the untu-
tored and unthinking the many welcome such
phenomena and the worlds science Is marshalllng
for new aud more brilliant conquests In the do
main Of astronomic discovery.
THE COMING ECL1PSE
OF the sun Will occur on the 5th OF April next.
The central eclipse begins on the earth little
southwest Of Cape Aguhas South Alrca), in longi-
tude 80 deg 10 min sec. east from Washington,
and in south latitude IS deg. 80 min., at lib
tact thus barely escapes the southern extremity
Of Africa ana the central line, along which the
SHADOW OF the moon QnterpOsed between the
earrh and SUM advances, runs from southwest to
northeast. Its track Is now almos: entirely
oceanic, passing southeast OF Madagascar and not
quite grazing its southeastern extremity. Thence
also missing Maurltlus where an able body Of OBJ.
servers could take the field, 1t dts rapidly
onward, crossing the Equator in about lon.
gitude lee deg east from Washington, or
ABOUT 80 deg east from Greenwich. 1t
then strikes Zig. ~ through the Nlcobar
islands, in the part OF the Bay OF Bengal
and sweeps across Tenasserim. Siam and Anam,
passing out into the China Sea and finally making
tts last contact on the open bosom OF the Pacific
little northeast OF the Ladrone Islands. The point
OF this last contact Is about LAT deg east Of Green
witch. IN latitude q deg. IL min north, and occurs
ct about l5a l2m, Washington mean time.
To give clearer idea OF the phenomenon In
question the diagram Fig. 2 IS presented. Al
though 1t is partly seif.explanatory and graphic
ally shows the
PHYSICAL PHENOMENA OF THE ECLIPSE,
II may be we'll to notice the conditions under
which such an observation OF the sun occurs. Tho
eclipse OF the sun is caused BY tho interpostion OF
the moon between the earth and the sun, and
when the concal shadow which the interposed
moon projects ochind her In space reaches the
earth, the points OF the terrestrial surface which
1t alls are completely deprived OF solar light
and involved In total darkness. Those parts
OF the earth covered by the moons penumbra
are, however, shrouded In but partial darkness
because from these parts only portion Of the
light rom the solar disk Is Intercepted. Accord.
ing 70 the relative positions OF the sun, moon and
earth, variety OF solar eclpses Ia presented. II
the apparent diameter oil the moon happens to be
greater than that OF the sun, the observation OF
the great lpminary viii be total, a. In the
approaching phenomenon to DO observed in siam.
II the moons apparent diameter be smaller than
that OF the sun. q luminous ring. formed by tho
unooscured portion OF the solsr disk, Is visible,
and the eclipse Ia thcn annular-an instance which
Will occur and be observable at Washington on
the 2Sth OF next september. II the moons certre
Ia not exactly upon o straight limo joining the
SUMS aud the earth's centre, the solar disk can,
OF course, he but partially concealed and tho
eclipse is partial; but when the centres OF tho
thrcs orbs lie on tho Same straight line, the result
IL central eclipse. The greatest possible excess
al the nnlr above the sofa. diameter. as
seen oy terrestrial oosei vor is only two minutes
o. q Degree so tnat tho greatest eclipse that can
ever or ant whore occur last only as long 1t
takes the moon to lass over about two minutes in
her croft, or about Jour minutes OF orr time. In
such case tho moons shadow covers only spot
about $50 miles broad, though tho penambra TOR
paruai shaaow) may thea darken circular spot
on tbs earths aar!aca having diameter OF nearly
1900 miles.
10 apure . tho SUMS centre (s) is seen 70 be in
straight line with the moons centre (M) ana the
earth's centre tEl, and the reader Ia supposed to
DO looking down on the earths northern hemis.
tnets. The Garth tinarkod ~ u rotating on its