Perrysburg journal. (Perrysburg, Wood Co., O. [Ohio]) 186?-1965, 1873-02-28
What We Know Of the SUI.

Institute, Dy frOIesSOT " "A. 1Oung, on |
"Our Present Knowledge of the Sum"
The professor said: Not only is the |
sum 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, deriyed 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
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 1t 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 suns
distance from the earth will be accurately
ascertained. Tho distance is now
held to be $4,000 600 miles, with
a margin of 100000 miles for
error, which the expeditions alluded to
will probably reduce to $50, 900 or 200, 900
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 il would take 100 years
for the sensation of burning to reach his
nervous system. From the distance is
obtained the diameter, which is about
100000 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 1000,
900 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 NJ. Pouillet showed that if the
suns surface could be covered with an
envelope of ice forty feet thick it would
that if a cylinder of ice 40, 600 miles in
diameter could be darted at the
sun it would melt as fast as il
came. Many opinions have been held
, as to the source of this tremendous
: temperature, and as to whether or not il
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 2, 00(
3. years ago, and geology shows that though
+ the world has at times been hotter thar
it now is, yet it has also been colder
AS to the source of its heat, all is yet con
e lecture; it can hardly be chemical com
| l. 60 hal1 IS l. Al.
s sun would burn out in 5000 years; th,
o heat is also held to be from meteors i'm
= pinging on the body, and doubtless this
r has its effect, yet it seems probable tha
0 the true cause is gradual contraction o
{ its mass, since a contraction of 100 feet o.
b its radius per year, woald account for al
Z the heat given off. Touching the physi
: cal appearance and condition of the sun
d it is great mass of gas on the outer POI
>. tions of which there are metallic vapor
|. ever condensing and forming clouds. II
p appearance warrants this assertion; it
t granulations, facul@ and spots all carr
i out the belief. The spots rotate with tn
:. sun, which performs its axial rotation a
l. the equator once in about twenty.iv
/. days, although when great numbers @
Z them are in process of formation the
4" seem to leap forward, a fact readily el
h motions of mobile gases. These spots
e many illustrations of which we here cas-
is upon the scTeen-have dark centre G
Y nucleus, and are generally gradually d.
}, pressed towards this center below tn
N surface; this fact is certain, although
l does not justify the belief that they al
If holes in the chromosphere throug
IN which the sun itself can be seer
ID They change in form far moi
N swiftly as do clouds on a summer
E. day, showing beyond peradventure this
D. they are not composed of dense matte
y. which could not be subject to such vici
I'd situdes; sometimes they change at tn
p. rate of 1000 miles an hour. Spots al
g. not alike numerous on all parts of Ii
it. solar surface; they are not common
II. the equator, but are seen mostly in VIII
C. might be called the temperate zones. NJ
&C. are they equally frequent in differen
: years; first there win be numbers
them; then for about three years the
will diminish again to reach their max
no mum at ten years from their first appea
lie ance. De la Rue and Darlington thougl
et that their frequency depends on ceTta
yo positions of the planets Mars, Jupite
he and Venus, but this needs confirmation
re. and 1t is probable that they are only pei
en- odical boilings-over from below. As
of their nature, Father Secchi and the FrenC
.s physicists have thought they were cav
We ties through which gas was blown u
re wards, attended consequently by draugh
as inward, but spectroscopic examinatiC
er shows no evolution from the centre Whi
ol. it does from the edges. Zoliner beliy'
en- them made by the throwing up of sla
in. and as to whether they are caused by
he thrush or an outrush 1t is not now pos
in BILE to say, Mr.. Lockyer being incline
oy few years ago, TO accept the latter e
a planation. During a total eclipse of q
by sun the dark body Of the moon is seen
le- be surrounded by halo, the nature al
origin of which have long been d
cussed, as to whether 1t W
an caused by the suns atmosphere
in IA thin atmosphere of the earth G