Spirit of the age. [volume] (Woodstock, Vt.) 1845-1913, 1886-11-03
THE ORB OF DAY.
Facts About the Solar Systems Central
Engine.

Facts About the Solar Systems Central
Engine.
The visible globe of the sun is /, 250,-
900 times rs large as the earth; within
the surface so seen their lies mass eX-
cccding the earths $4,000 times; the
materials present in the suns globe are
thu same rs those which form the globo
oil or earth-at least, we know that
iron, copper, zinc, sodium, magnesium.
calcium, titanium, and 4 number of
Other metallic elements are present;
hydrogen is certainly there in enor-
nous quantities, and DR.. Henry Draper
proved also that oxygen is present, and
no astronomer doubts that those other
elements which have not as yet been
detected in the sun are really present in
his mass.
Now, have we any evidence us to the
way in which the mighty mass of the
sun is disposed within that surface
which incloSes what we term his vol
ume?-though in reality one can hardly
say what his volume is, seeing that
there are portions OF his mass outside
the surface which bounds his visible
globe. Is the suns mass uniformly
distributed throughout that visible globe,
100000 times rs large rs our carthP
or, on the other hand, is the dcnscr
part near the surface SO that the sun is
what Prof. Young once suggested,
gigantic bubble? There are three lines
on which we can seek for an answer to
these questions.
Firstly, we find that the visible sur.
face of the sun behaves in a manner in
consistent alike with the idea that this
surface is near the real surface of an in
fcrior globe and with the idea that the
visible surface is part of Il mighty vesicle
or bubble The spot zones are carried
around at different rates, according to
their distance from the equatorial solar
regions. Not TO follow Faye and others
in niceties of calculation Qar from justi-
fled by the evidence we have), may
say that the equatorial zone gains about
one rotation in seven on the spot zones,
or, roughly, some 100000 miles in 200
dayS-say 1850 miles per day. Such
velocity rs this, close on ten miles in
minute, could not possibly exist in a
cloud-ladcn region (such rs the visible
surface of the sun undoubtedly is), and
as affecting regions exceeding the whole
surface of the earth thousands OF times,
unless that cloud-laden region were
very far away from the real surface of
the sun, and therefore from the fraction
al effects OF the true solar rotation. The
real mass of the sun, however distribu-
ted, can only rotate as one; the visible
cloud surface has many rates of rota
ton; therefore there must be an enor.
nous distance between the two.
Secondly, calculation has been made
by competent mathematician respect
ing the amount of polar compression
which would arise from the rotation oil
globe such as the sun appears to be at
the average rate of rotation indicated
by the solar spots. 1t is found that the
polar hattening would be well within
the measuring capacity of our best in.
Struments. But if there is one thing !
certain about the sun, it is that (wthin
such capacity his apparent globe is no, !
fattened at all. 1t is absolutely Ger.
tain, then, that the real globe OF the sun
lies far within the surface of flowing
clouds which VIC see and measure.
Thirdly, our earth has her story to .
tell about the suns interior. We know
from the earth's crust that, for periods
Of time which geologists now estimate
by tens Of millions of years, the suns
hao hao,, nj ,rn,ly tho norfh'C
crust, by rain, wind, and storm. fash
Joining and refashioning the structures
of that crust, now forming layers, anon
cutting them up, but throughout leaving
clear traces of his handiwork. Croll
estimates the duration of this part of
the earth's history-that is, of the time
during which the earth's crust has been
forming under solar action-at fully
100,000,000 years. In other words, our
earth tells us of at least 100000
years of sun work, at the suns present
rate of working. 1t is matter of no
Importance whether we suppose that the
sun has worked all the time at the pres.
ent rate, or has sometimes worked with
more energy, sometimes with less. 1t
is the quantity of sun work, not the way
in which the work has been done, which
alone has to be considered Now, all
physicists and astronomers are agreed
regarding the suns emission of heat as
due wholly or almost wholly to solar
gravltation, resulting in the steady con-
traction of the suns mass. To get
from the sun of past ages the amount of
tuprly n, hi,h rth falls l,a hoo
actually done, we must suppose him
once to have been very much larger
than he is now-how much larger we
cannot say.
/ take it also that the change which
takes place in the aspect of the suns
corona as the number of sun spots
varies, and the alteration of the physical
that when there are many spots its
spectrum indicates the presence of glow
ing hydrogen, whereas, when there are
few, the lines of hydrogen are few or
wanting correspond also with the
theory that the time of sun-spots is
time of great eruptional activity. For
the rush of elected masses through the
NoiOhai Nouiu StiuoO
gen present there mot an atmosphere,
but irregularly distributed and moving
around the sun) to glow with greater
luster, so as to show the lines Of hydro ,
gen in the spectrum of the corona.
1t is at any rate remarkable that all !
the facts known to US in regard to the
sun-spots themselves, to the coiored
flames, and to the corona, should agree
in confirming that which is already all .
but demonstrated by three strong lines
of evidence, that the real working mass /
of the sun is very much smaller than
the globe we measure rs his and that |
all the phenomena which give so great
an interest to the study of the sun are
due TO tremendous forces at work tens
of thousands of miles below the surface
which limits our view OF his globe and
hides from us the processes by which
the life of the solar system is maintain
cd. -Harper's Magazine.