Bristol news. [volume] (Bristol, Va. & Tenn.) 1867-189?, 1874-08-25
WHAT WE KNOW OF THE
Sun.
Professor Young Oh Solar Pho
nOmcna.

Although last evening was exceed
in9ly Indictment comparatively large
number Of people attended Professor
&. y. Young's lecture, at Cooper
Institute on "Or PreSe t knowledge
of the Sun The Professor said:
Not only is the sun the centre of our
system but is more than this-it is
the Scource of all energy in and upon
the earth; of animals and vegetables
of wind and rain, and even of steam
power, which, derived indirectly from
coal-the "bottle sunshine" Of
StephenSOn-iS in the last resource
derived from the sun. Nervous and
muscular power, the moveme ITS of
our limbs, our voices, and even men,
tai action itself has its source in the
central FIRE. II is true that each staI
sends little heat to the earth, and
there is some degree of it from one
or two other origins, but that little
can scarcely be appreciated. Of late
years science has been much engaged
in investigating the sun, and first of
all it is necessary to obtain its dis
lance as postulates for finding its
size. Il is not difficult to discover
its relative distance in the system by
making use Of third law of Kepler,
but so hard is it to obtain its distance
from the earth in miles that it was
not till the last century that this was
done. Antique methods cannot be
relied on. and the one now in use is
that derived from watching the transit
of Venus and getting its parallax.
Yet this is not without its difficulties.
owing to the refraction of light. In
obtaining the exact position of Venus
against the sun the Germans use the
Leliometer, which gives very accurate
results. The French and Americans
rely upon photography, and this is
probably the most accurate method.
To observe the transit which will
take place this year Russia will have
twenty live stations, and France, Eng
land, Germany, and America will send
out expeditions fully equipped, Be
sides these Lord Lindsay will send
one at his own expense to the Maui
ritius, and it is likely that the suns
distance from the earth will be &C
carately ascertained. The distance
is now held to be 92,000,000 miles,
with margin of 50O,0 miles for
error, which the expeditions alluded
to will probably reduce to $50, 600
or 100000 miles. The Professor
used startling illustration Of what
this distance is, by saying that if his
arm were long enough TO reach the
sun it would take 100 years for the
sensations of burning to reach bis
nervous system. From the distance
is obtained the diameter, which is
about 100000 miles so that the earth
with its moon could be placed within
the sun and there yet would be room
for another moon. Its bulk is about
One-fourth million times that of the
earth, but its weight is only about
325, 900 times the earth's. The matt
ter of which il is composed is extreme
ly tenuous, and though there may be
solid or liquid drops within it there
can be no great space taken up by
anything denser than gas; its centre
is bubble of gas held in position
and condensed by the force of grav-
ity, which is there enormous Its
heat is intense but its exact tenn
perature is not known, a French savant
putting it at the heat of the electric
arc, Father Secchiat 10, 900. 600 dogs.
Fahrenheit. Captain Ericsson at
5000. 900 or 1000. 900 degs., and be-
tween these extremes there are various
estimates. The great difficulty with
all these figures is that they are found