An introduction to astronomy: designed as a text-book for the use of students in college. By Denison Olmsted ...

axis lto thc pllane of the ecliptic; but it was in fact by first ol-'ervint tlheet cllanges, tand proceeding in the reverse ordel
firom that which we lhave pursued, that astronomers aswertained that the sun revolves on hlis axis, and that this axis is
inclined to tle ecliptic 823~
51t. B:esides the spots already described, there are faint
inelqualitics of lighlt over the gencral surfiacc, in delicate lines
anl1d fvreldes, whicl atre also prpetuatlly challnging. Tlcese are
called fact.tz
T'lc theory, which is generally received, regards tile visible
surfacee of the sixun as ani incandesecnt, gaseous substance,
alwNays in violclnt commotion, and sometimes rent her and
tlere 1)y a l)road opening, whlich reveals a lower stratlum of
less illlmlination. Tllhis is the u lrat of a. spot a; td a smnaller
ruptultre itt t/atl showts al still lower stratum, or else the solid
b)ody of the stln, as thle.ticlde..s of the sanmeC. These aperturecs
inl the luminous strata may bet caused, as some01 think, by voletanic action below, or according to otherts by storms or tornados in the soal' atmosphere.
ZODIA(AL L IGXHT
I 5 2. The Zodiacal IAigaht is 1Fg. 30.
a fint lifghlt resembling tihe tail
of a comet, and is seen at cer- l
tailt seasons of thle year followfillg
the] cours(e of the Sun after evelnilng t.wilightt, or preceding his [
approach1 in the morning sky.
Figlure 30 represents its appcaranc;c as seen inl the evening, in...
M:.ar~cltl 183. Tlle following artle
1./Its foint i*s t/hat q[f a lta.d-.
ous tw tiri,.nle, h1aving its base
toward the sun. It reachles to
an immen11tse distance firom t llo.un, somnctinlls even beyond the