New-York tribune. [volume] (New York [N.Y.]) 1866-1924, 1870-01-22

whose distance be computed. and can therefore be
compared with that OF the sun.
When we view the sun through telescope OF moderate
provided with shade glass with solar
eye-pece, we bright disk in which no measuremsnt
circle is not Of equal brightness central portion
being much more brilliant than the parts near the er-
respects bnt the whole surface appears moted by small
variations in brilliancy which have been compared 70
the Irregularities upon the rnd OF an orange ana 10 the
uneven surface Of stormy sea.
SPOTS on THE sun
Usually, too, several spots groups OF spots OF IT.
regular and often fantastic shape to be seen various
ly distributed but almost always within belt crossing
the centrally, and not 80 wide onc-half his diane
ter These spots differ in size from the smallest visible
to breadth Of which ll6 Of the diameter of the
sun and corresponds to seven times that OF the earth
their forms and dimensions undergoing continual and
rapid changes Ordinarily, and, indeed, always II OF
parts, each sharply defined. viz dark inner portion
called the umbra or nucleus and an extensive graysh
penumbra Sometimes though not Often the sun is seen
entirely free from spots while at other tunes they are
one time Not unirequeny they are visible to the naked
eye through smoked glass.
observer with telescope of moderate power. viz:
and not to be confouEded with the general nothing of
the surface. These are called facul9 and are generally
fest regions the limb margin of the sun, where
the fainter light and some other causes, render them
especially conspicuous. Facule may almost always be
in the chose vicinity of the spots and generally to
the left OF them but they not restricted stu
atoms, and may be found In regions where spots are
never seen.
WILSON'S THEORY.
To explain the phenomena Of the spots, Domenic Cas-
SIM suggested in 1871. that the suns surface be
of light surrounding the dark and solid central
body of the sun, and whose tumultuous agitation
times dseloses some mountain summit which appears as
the black nucleus Of the spot This suggestive idea
formed however, only first step toward the solution OF
the problem, the honor OF which belongs TO Scotch as
trOnOmer, Glasgow,
later Wilson observed that the penumbra or grayish
border which surrounds the dark nucleus ana which is
generally of about equal width all sides when the spot
Is near the middle of the SUMS disc, always became mar
the side nearest the middle OF the when
the spot approached the circumference. Hence he in
forred IN 1873 that the spots funnelshaped aper
lures the luminous envelope which disclosed the dark
body OF the at the bottom and whose shelving aides
constituted the pcnumbra. moments inspection of the
middle Of the disc exhibit the full size Of the nucleus
f. ana equable border represented by the apparent
breadth vt ID and Of the inclined sides OF the open
ing bat that when Is the circumference at
or II, the nearest side becomes foreshortened as
does also the nucleus LCdgh to less extent while the
farthes SIDE OF the aperture Is presented much moro
IT, therefore the appearances be as stated by Wilson,
the inference seems Irresistible that the spots are OPEN
ngs in the glowing envelope % the sun. To make sure
OF the the case the Directors of the Kew Obser
vatory have carried out an extensive examination OF all
the drawings and photographs Of solar spots which they
could make available and the enormous preponderance
of observations in favor OF this theory must be considered
suggested the of the stereoscope to decide whether
the spots actually cavities depressions, with the
eau hardly be deemed conclusive, for senses are
tricky guides, and things are not always what they
seem.
But why should the sleping sides of such cavity
est THAI dminuon OF the solar luster which the Pc
would be partially through 1t, would be our first
reply but moments thought VIII show that were this
ent degrees OF luminosity and shade gradually away
from full brightness at It's circumference 10 az
boundaries Oft penumbra sharply defined and its
color lis toleraby uniform throughout. 10 this diff
German
envelope Of cloudy nature supported by an atmos-
phere, and situated between the true body Of the sur
velope is called. The reflection Of the photosphere
the penumbra while the nucleus of the spot would be
the body of the through tho opening In this
HeTsche added ,he idea that the transparent elastic
atmosphere in which the stratum OF clouds must be
supported. and extended beyond, the philosophers
Eliminating from the true surface OF the sun this gaseous
atmosphere sreamed upward, dispacing the material OF
the surrounding cloudy stratum ana OF the thinner
identical with this theory OF Herschel had boon
propouDded early the middle OF the hteenth cen
ury, before the existence OF the spots was Known 10
astronomers yet this must be regarded rather as ior
guess oI aan m yew can be iS 1e
The general aspect of solar spots viii be seen by the
representations in the diagrams The enormous nsgni-
tude of some spots has been already mentOned-huge
chasms which cover an area OF some two billions Of
forty or nifty globes large our earth: Their con.
tnual and rapid changes Of form and SIZE, make 1t
peculiarly difficult settle many interesting questions
concerning them. but decided indications OF rotary
motion have been observed in many OF them, winch
would imply that they turning like huge whrlpoois
around their own centers. Inc nucleus, although We
speak of 1t black and although appears intensely so
IN contrast with the glowing radiance Of the surrounding
portions, s in itself by 10 means devoid Of brightness:
n has been well said BY Wnuecke that we're the Light Of
the whole be eXtiugnished excepting tho portion
radiating from the nucleus OF spot, our eyes would
scarcely be able to endure the dazzling beams HerSchcs
estimate has generally been considered too low, yeti
would give the dark nucleus of spot luminous nten
curious and frequent appearance Is that OF socaed
bridges which often cross spot dividing IL ilKe paI
penumbra well as nucleus while IN other cases they
brighter than tho pennInbra, ana only peIcepuDe
when IN contrast with The dark nucleus. Both their for
nation and disappearance have been frequently OBJ
served tongues OF eht are seen darng across from one
side FROM both sides toward each other, until the
bridge is established and IN way not unlike that which
natuTaistS describe Wnen microscopic Organic forms are
in process Of development; and again they are eeen TO
fade gradually away, growing fainter and fainter, uGt
fro br gtness they nave seemed TO dissolve
and disappear These also depicted in the diagrams
GRANULAR SURFACE or THE sun.
About the year 1863 MIR. Nasmyth announced the dis
coyery that with powerful telescope Of sharp defining
power and under favorable atmospheric conditions the
whole luminous surface q the sun appeared 10 con
eist OF thin layer OF bright ainents shaped like willow
leaves averaging abont 1000 mies In length and 100 IN
i'm every variety Of direction across each other. and that
the black points we're simply the ihieialces between
lated at very minute scrutiny ot the lace OF inc
sun. aud ~ active controversy among The CDseiVegs
All agreed that the luminous surface composed OF
bright particles, but Nasmyths description found but
little continuation One observer proposed the term rice
grains better representing tue form Of the objects IN
question: and another compared them to pravel Oh te
beach, aud third preferred the word EXAMINATIONS Inc
Higgins OF London. The grduues Of
various sizes, but may on the average
and in BREADTH corresponding about 81; by $50 aies
Some nearly round, others oval, and others tti
ding OF the solar disc arises chiefly from the alienation
Of lines or groups OF closely aggregated granne ana OF