Wyandot County Republican. [volume] (Upper Sandusky, Ohio) 1869-1903, 1873-02-27
What We Know of the Sun.

The New York World gives the follow
ing summary of recent lecture at Cooper
Institute, by Professor G. A. Young, on
"Our Present knowledge of the Sum-"
The professor said: Not only is the
sun the centre of our system, but it is
more than this-it is the source of all en-
ergy in and upon the earth; of animals
and vegetables, of wind and rain, and
even of steam power, which, derived in
directly from coal-the ''bottled sun
shine" of Stephenson-is in the last re-
source derived from the sun. Nervous
and muscular power, the movements of
our limbs, our voices, and even mental
action itself has its source in the great
central fire. 1t is true that each star sends
a little heat to the earth, and there is some
degree of it from one or two other origins,
but that little can scarcely be appreciat-
ed. OF late years science has been much
engaged in investigating the sun, and
first of all it is necessary to obtain its
distance as postulates for finding its size.
1t is not difficult to discover its relative
distance in the system by making use of
the third law of Keppler, but so hard is
it to obtain its distance from the earth in
miles that was not till the last century
that this was done. Antique methods
cannot be relied on, and the one new 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 OBJ
tanning the exact position of Venus
against the sun, the Germans use the
hellometer, 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 next
year Russia will have twenty-five stations,
and France, England, Germany and
America will send out expeditions fully
equipped. Besides these Lord Lindsay
will send one at his own expense to the
Mauritius, and it is likely that the SUMS
distance from the earth will be accurately
ascertained. The distance is now
held to be $4,000 600 miles, with
margin of 100000 miles for
error, which the expeditions alluded to
will probably reduce to $50, 900 or 300, 600
miles The professor used a 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 sensation of burning to reach his
nervous system. From the distance is
obtained the diameter, which is about
$50, 600 miles. Its bulk is about one and
one-fourth million times that of the earth,
but its weight is only about 325, 900 times
the earth's. The matter of which it is
composed is extremely 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 CEN
tire is bubble of gas held in position and
condensed by the force of gravity, which
is there enormous. Its heat is intense
but its exact temperature is not known, a
French savant putting it at the heat of
the electric arc, Father Secchi at &C, ,OOO,-
600 degs. Fahrenheit, Capt. Ericsson at
5000, 600 or 100000 degs., and between
these extremes there are various esti-
mates. The great difficulty with all these
figures is that they are founded on the
analogy of heat on the earth with that
coming from the great distance of the
sun. But although impossible to meas
are its intensity it is not SO with its
quantity, as emitted in given time: the
standard is the quantity of heat required
to heat one pound of water one degree or
to melt pound of ice. Sir John Her
schell and III. Pouillet showed that if the
suns surface could be covered with an
envelope of ice forty feet thick it would
that If cylinder of ice 10000 miles in
diameter could be darted at the
sun it would melt as fast as it
came. Many opinions have been held
as to the source of this tremendous
temperature, and as to whether or not it
was gradually growing less. There is no
evidence in regard to the latter question,
but, if falling off at all, it is impercepti-
BILE, the same vegetation growing now on
the earth in places where it grew 1000
years ago, and geology shows that though
the world has at times been hotter than
it now is, yet it has also been colder.
As to the source of its heat, all is vet con-
lecture; it can hardly be chemical com.
bination, for a ball of coal as big as the
sun would burn out in 5000 years; the
heat is also held to be from meteors i'm
pinging on the body, and doubtless this
has its effect, yet it seems probable that
the true cause is gradual contraction OF
its mass, since contraction of 120 feet of
its radius per year, would account for all
the heat given off. Touching the physi
cal appearance and condition of the sun,
it is great mass of gas on the outer por
tions of which there are metallic yapors
ever condensing and forming clouds. Its
appearance warrants this assertion; its
granulatiens, facula and spots all carry
out the belief. The spots rotate with the
sun, which performs its axial rotation al
the equator once in about twenty five
days, although when great numbers Of
them are in process of formation they
seem to leap forward, fact readily ex
| planned on the supposition that they are
| motions of mobile gases. These spots
| many illustrations of which we here cast
upon the screen-have dark centre o.
nucleus, and are generally gradually de
| pressed towards this center below tn,
| surface; this fact is certain, although il
does not justify the belief that they art
holes in the chromosphere through
which the sun itself can be seen
They change in form far more
swiftly as do clouds ON a summer,
day, showing beyond peradventure thai
they are not composed of dense matte!
which could not be subject to such vicis
situdes; sometimes they change at thu
rate Of 1000 miles an hour. Spots are
not alike numerous on all parts of tn,
solar surface; they are not common a
the equator, but are seen mostly in wha
might be called the temperate zones. No
are they equally frequent in differen
years; first there will be numbers o
them; then for about three years they
will diminish again to reach their maxi
mum at ten years from their first appear
ance. De la Rue and Darlington though
that their frequency depends on certain
positions of the planets Mars, Jupiter
and Venus, but this needs confirmation
and it is probable that they are only peri
odical boilings-over from below. As t,
their nature, Father Secchi and the Frencl
physicists have thought they were cavi
ties through which gas was blown Hp
wards, attended consequently by draught
inward, but spectroscopic examination
shows no evolution from the centre Will
it does from the edges. Zoliner belivst
them made by the throwing up of Stag
and as to whether they are caused by al
thrush or an outrush it is not now posi-
BILE to say, Mr.. Lockyer being inclined
a few years ago, to accept the latter ex
planation. During total eclipse of tn
sun the dark body of the moon is seen t.
be surrounded by halo, the nature an,
origin of which have long been dis
cussed, as to whether it wa
caused by the suns atmosphere o