Bristol news. [volume] (Bristol, Va. & Tenn.) 1867-189?, 1870-02-11
Stieutift.
CONCLUDED FROM LAST ISSUE.
CONSTITUTION OF THE sun.
DIR. b. A. GOULD ON IHE CON
STrTUTION OF THESUN.
WILSON'S THEORY.


Domenic C'ss nj suggested, IN 1911, that
the suns surface must be an ocean ct zig u,
surrounding he dark snd solid central
body OF the sun, aud VIII $50 tumultuous
agitation sometimes discluses some noun.
tain summit which appears as the black nu-
c'eus OF the spot. This suggestive idea
formed, however, only a first step toward
the solution of the problem, the honor Of
which belongs to a ScoIch astronomer. Prof.
Alexander Wilson of Glasgow, 100 Years
later. Wilson observed that the pehumbra
or grayish border which suTronds the dark
nucleus, AMI which IL genei ally about equal
width on all sides when the spot Is near the
middle OF the suns disc, always became
narrower on the side nearest the sun, when
the spot approached the circunii, reuce -
llo Inferred in l773 that tie spots were
tunnel shaped 9per' ures ia the luminous
envelope, which disclosed tOe dark body ~
the sun at the bottom, AMI whose shelving
sides cJhs,i'u'ed the pcnumbra.
II, therefore, the appearance lie rs stated
by Wilson, the Inference seems irr, sis'iul,-
Tue spots are ola mugs in the glowing en-
gel'pe Ui The sun. T. make sure OF the
ttc's Ia the case, the ID rrctors Ut The K"S
OOseIvat' Ty have carried out an extensive
oxunIna' lon OF 81. the drawir IS and photo
STsphs Of the solar spots, VIII ca they could
make hYpildJir, and The enormous prepon-
derance of observations in favor ut this
theory must he nsidered as d"fiately ct
ling the DIGESTION. Mr.. d. La Rae sso
suggested the use of the stcreUscope 10 de-
eide whether the spots are actually caFi'i-g
Or depressious, with the ssnIe result. Bat
this argument, alth.u5h strong ore, can
hardly he deemed conclusive, tor our sen
ses are tricky guides, aud thing, are not al
WAYS what they seem.
Blu, why should the slpping slider OF such
cavity manifest that dluIiutinu of tho SO
lar lustrr which The pruumhrt exaiDts p
b cause the darker body Of the suu would
ne partially seen through e., ~ ould lie QUE
irst reply ; but nom MS thought Will
show that were this the trOe explan Il on,
the penumbra would exhib off rent de-
grees of Luminosity, ami shade gradually
away from the full brightness as its circum-
iarence to dlrkuess al its inner margin.--
This is not the appearance but the bound
aries OF The pehumbra are sharply d. fined
aud its color is tulerably uniform through
out. To meet this difficulty the German
astronomer Bode, As>Omt d a second envel-
ope Of a cloudy nature, supported by an
atmNsph, re, ami situated between the true
body Ui the sun aud the atmosphere, as the
outer light-giving envelope rs called. The
reflection OF the philosophers from this str
face would account Tor the light Of the PEE
numbra, while the nucleus of the spot
would be the body OF the sun as seen thro'
the opening in this second envelope. T"en-
ty years later, the great William Htrschel
lded the idea that the transparent, elastic
atmosphere in which the stratum Of clouds
must be suspended at height Of not less
than 4 1000 miles, likewise supported, and
extended beyond the photospere. EmanAt-
| ing from the true surface of the spn, this
gaseous atmosphere streamed upward, dis
placing the material of the surrounding
cloudy stratum and the thinner photo
sphere, IL Is a curious fact that hypor he
sis almost identical with this theory OF Her
schel had been propoupded a. early as the
middle Of the dteenth century, before the
existence OF the spots was known TO astrOn-
omers yet this mnst b. regarded rather AS
a fortunate gu IS than as a scientific theory,
Cor the evidonce by which alone such Wow
can be- supported was not then k,oSD.
The general aspect Of the 81 ar spots VIII
be seen by the representations Ia he dia-
| grams. The enormous magnitude OF some
spots has already been msntiOned--hugr
| chasms which cover ao area OF some Two
| billions of square miles, and whose mOu hs
/ wonld receive at once forty or my globes
a, large as our earth. Their continu, aud
! rapid changes of form and size, make IL pc,
| culiarly difficult to settle msny inter sung
/ questions concerning them, but decided in-
| dicatons Of rotary motion have been ,b'
served IN many of item, which would im>
| ply that they are turning Ike hug wtlrl'
pools around their own crpteIs. The nu.
cleus, although We speak of II AS black, aud
although itappesrs in ensely 80 ia contrast
| with the glowing radiance ~ the surround
rug portions, Is IN itsell by n mrsGs deyod
| OF brightness. IL has been well sst by
| Winnecke, that were the lght of tie
whole sun To b. extingui- he'd, excepting
the portion radiatng from the nrcltus at a
spot, our eyes would scarcely DO able lu
endure the dazzling beams. Herscheps es
innate has generally been considered tol
low, yet It would give the dark nucleus of
a spot luminous intensity, nearly 1900
times greaier than that uf the fui moon.
A curious aud r. quent appearance is
that Of So-called b iiges, which often cross
a spot, viding IL like parti ions. Somt =
time, these aro IN EMS ly brilliant, crossing
penunibra as ", Ii as bu,lvu-, While ia other
cases they are no brighter than the peuum-
bra, aud only prrt eptibls whrn In contrast
| Sith the dark nucleus b th their fOrma
tiou and disappearance have been fr, u 'ntly
observed tongues OF light are seen darts
ing across frum Que side, or FROM both sides
toward each other, uaiil the bridge Is rs
tabhshed, and IN way not unlike that
which uaiuralists describe When mier, scop-
pic orSanic forms are in process OF develop
meng aud sgain they Are seen 10 Jade
gradually away, growing fainter aud faiutrr,
autii from al intense brightness they have
seemed 20 dissolve and disappear.
GRANULAR susFAcE OF rus sun.
About the year 1853, Mr.. Nasmyth an
nounced the discovery mat With powerful
telescope ot sharp deuatng power, and uu-
der faSorble atmospheric conditions, the
whole luminous surface OF the snn apprar-