New-York tribune. [volume] (New York [N.Y.]) 1866-1924, 1869-08-04
TIE SOLAR ECLIPSE.

The grand and imposing celestial phenOme-
non which will occur on the 18th of this month
is TO be observed with unusual scrutiny by
American astronomers. In anticipation of this
event, extensive preparations have already been
made for erecting temporary obseryatories. Six
parties now organized will soon be in position,
with all the requisite instruments and appa-
ratus on or near the central line of totalty !;
the most northcry point of observation being in
Alaska, and the most southcrly at Louisville,
Ky These expeditions are under the auspices
of the Coast Survey and several of our princi-
pal institutions of learning. Yet it is
quite probable that private expeditions
will be organized for the same purpose, of
which we may hear nothing until they have
published the results of their observations.
1t will be remembered that n total eclipse Of
the sun, visible in Southern Asia on the 18th
of August, 1863, was observed by the Prussian
expedition ut Alden, Arabia, and by the French
and English physicists at points much further
east, In India. The period of totalty was
unusually long, for the moon had just passed
q perigee of uncommon proximity and during
the eclipse she reached the ascending node of
her orbit Under these favorable circumstances,
by the spcctroscope and the lunar photograph
would furnish some decisive evidence touch
ing the form and composition of our
central luminary, since it is only during
such q phenomenon that solar emanations
at right angles to the line of vision are unob-
structed by direct lays. 1t is, however to be
regretted that, for reasons which need not here
be stated the English expedition failed to
throw any new light on the question of the
constitution of the sun. The best photographs
of the eclipse were made by DR.. FritSch and
his associates at Alden, where the time of
totality was much shorter than at the stations
in India. In these pictures two separate ranges
of viOlet-cOlored promnences, each embracing
about Onesixth of the moons circumference
were represented, while on the opposite side
was shown the peculiar hook-shaped projec-
ton, the hight of which is estimated at almost
one. fourteenth of the suns diameter, or about
10000 miles. DR.. Jansen, the head of the
French expedition, reported that q spectre
scOpic examination of the prominence3 showed
them to be gaseous emanatOns-in fact, vcri-
table hames-and not, rs many had previously
supposed, masses of condensed vapOrs rcscm-
bling terrestrial clouds.
1t will be the aim of our observers TO test the
accuracy of this conclusion and by the use of
the spcctrOscOpe, during the brief interval of
totality, to search for those peculiar lines in the
spectrum which indicate the presence of cemen-
tary substances identical with some Of those
found on the earth. 1t is fortunate for the cause
of Science that appearances so evancsccnt as
those presented during the period of total
observation may be1copied and preserved by
means of the photograph. Should lunar pic
lures be taken at each Of the stations men
toned, comparison of them will enable the
scientist to settle the.question us to the changes
of form which these remarkable prOmincnces
and projections may undergo during n given
time. 1t is not improbable that the actinic
force from the corona and solar emanati0ns
may reveal, in pictures, the presence of matter
which could not be detected by the human eye
Comparatively few of our readers will be so
fortunately located on the 9TH of August
as to come entirely within the cone Of shade
which reaches from the moon TO the earth and
thus be envelopcd for a brief interval with the
mantle Of lunar night; yet large majority
may witness, il the SKY is cloudlcS5. partial