The evening telegraph. [volume] (Philadelphia [Pa.]) 1864-1918, 1868-07-27

il that the question, il is hoped, will receive at
leas, partial solution. All have by tn time
heard of spectrum analysis, the wonderful
power by which the physicist armed only with
wedge Of glass. can tell us the source ot light
coming from sun from star, from comet from
uebula.
Kirchoif. the honored discoverer of this means
OF research, has told us that the sun s sur
rounded by an intensely heated atmosphere,
charged with the vapors of metals and other in.
gradients which the prism has enabled him and
o hers to sort and separate, and thus 10 identity
with metals aud ingredients common to our
globe Are these red, cloud-like masses skim
ming apparently over the solar surface, aggte-
cations Gf this vapor, flames of burning metals?
Do they glow with their own lncandescaut light,
or are they lit by the bright sea on which they
float? Are they solid masses of matter, or are
they atteDuated gases? These are the points
which 1t is hoped will be settled in whole or in
part on the 18th of August on the hills of india
The observers will ply their polariscopes to de-
termine whether the light be original or re-
hected. Then they will pass its beams through
the prism; If they see a long spectrum, colored
with all the tints of the rainbow, they will know
that they are looking upon masses of solid or
liquid matter IN combustion; If this spectrum
Is crossed by black lines, they will know that
its light on Its way TO the earth has been
intercepted by the vapors Of certain metals
and by certain gases, which they will recognize,
by the positions of the lines; but II, instead of
the rainbow-tnted ribbon, they see only certain
isolated bright lines, like colored threads
stretched across the fields of their spectros copes
they will know that they are looking upon
materials so intensely heated that they have
assumed the gaseous condition; and by tue
positions and colors of these threads of light
they will be able to ascertain to some extent
what these materials are. Aud what they will
do Tor the red eXcTescences, they will ehdeavor
to do also for the corona, that they may learn
something of the light wherewith 1t shines. So
that the most important questions bearing upon
the suns constitution and structure are to be
solved when he is out of sight! A strange
anomaly; but nature is forever playing at hide
and.seek with man.
To do justice to these observations, two we'll
furnished expeditions have been organized in
this country, respectively under the auspices Of
the Royal and the Royal Astronomical Socie-
ties. Lieutenant Herschel "a son Of Sir John),
OF the Indian Survey staff, takes charge of the
former, and Major Tenant, of the same SER
vice, directs the latter. Both have been supplied
with excellent telescopes and polarzlng and
specializing apparatus; Major Tenant, in ad-
dition, having secured the manufacture for the
occasion OF valuable rejecting telescope Of
large size, for the purpose Of photOgraphing the
eclipse phenomena. Other officers of the survey
staff will be dispersed along the track of the
eclipse, and will be armed with spectroscopes,
and such appliances as the country may afford,
in order that what is lost by bad weather in one
spot may be secured elsewhere. Other coun.
tries, too, will have their expeditions. France
furnishes two and Prussia one, and for these
handsome sums of money have been voted; aud
possibly his Holiness the Pope may send Padre
Secch TO the spot, though at present pecuniary
difficulties stand in the way. Altogether, we
may hope that an important page of scientific
history will be that which records the results of
the great eclipse of August II, 1865 Gentle
mems Magazine.