The times. [volume] (Washington [D.C.]) 1897-1901, 1900-02-11
isible as halo about the mass of the.

| visible as a halo about the mass OF thu
orb.
The appearance OF the corona, however,
varies in different photographs which are
made of il. At times 1t takes the form
| of halo of light around the sun: at 9TH
er periods ii is a general glow, but mo-
| frequently ii. Is seen as long smart ek-
| tending from opposite sides. photographs
taken during the last total eclipse IN ire
United States, in 1878. show that II w
visible for a distance of 100000 mi es on
| each side of the sun. Owing 10 the in
tensely luminous character OF the sun, It
has been impossible to observe this feature
except at times when the disc was hidden
by the moon. For the past twenty-five
years efforts have been made to photo
graph the corona on the most sensitive
plates that could be made. but these ex-
periments have met with little success
Although much data has been gathered
concerning the corona, the questions o. its
real composition and connection with the
sun are merely coniectural
Besides the corona. the most important
features of a total solar eclipse. are the
red prominences and the sierra or chro-
mosphcre. There are lesser phenomena
such as "Bailey's beads" which are said
TO be of no Importance whatever.
Studying the Phenomena.
The red prominences were first seen dur
ing the solar eclipse of July s. 1872 Dur
ing the eclipse of July IS. 1851, 1t was
shown conclusivelys that they belonged TO
the sun and not to the moon as some had
previously contended. The principal evil
dences upon this point. however, are the
Photographic records which De La Rue
and nj
eclipse of June is, 1860. It was not until
the eclipse of August, 1868. sometimes
known as the great Indian eclipse, that
the real nature of these wonderful red
prominences was ascertained. Spectroscop-
ic analysis was applied successfully to the
investigation of the prominences by Col
onel Tenant. Captain Herschel and NM.
Jansen and Rayet. The spectrum was
found to consist of bright lines. indicating
that the colored prominences are masses
of glowing vapor. All the observers were
agreed that among the bright lines those
of hydrogen were present. and the pres
ence of sodium was also demonstrated.
Prof. Young, of Dartmouth College. has
acquired an international fame on account
of his Investigations OF these red promi-
nences and contributed in great measure
to the perfected method by which they are
at present observed without the aid of
an eclipse. These phenomena have the
appearance of jets fountains of flame,
rising sometimes to height of 10000
miles, and assuming at their altitude the
most beautiful and complex forms.
The phenomena of the sierra was dis
covered before the red prominences. and
is a border Of dark red which can be seen
on the eastern side of the solar disc just
after the totally has commenced and on
the western side just before totality ceas-
es. This appearance has given rise to the
discovery that a continuous red envelope
surrounds the sun 10 a depth of three or
four thousand miles. The name of chro-
mosphere has recently supplanted that of
sierra.
Each new total eclipse develops addi-
tional and important facts in connection
with the solar system and 1t is with great
anticipation of further knowledge that the
coming event is looked forward TO by as
tronomers all over the world. The leading
scientific bodies of Europe have annoinc-
ed their intention of sending delegat. ons
TO this country and thus the American
astronomer will have an opportunity to
compare notes with his transatlantic col
league.