The sun., 1894-05-05

LsniAsus tIouds vis,Sis ~ Might whe..
Oriain Is Uasxpiatnss.


Among the most mysterious phenousns IN
the heavens are the luminous night clouds" :"
which were fret noticed in Germany in 1895.
and which should be visible near the end OF
the present month. Their annual period OF
visibility at Berlin has been from May 20 TO
Aug. ii. After that they can be seen n at all.
only In the southern hemisphere. On at least
one occasion they have been noticed in South
America in December. some singular change
evidently Affects them. and they are Rraduslly
disappearing. For four years after their dis
eovery they were visible In both the even
ing and the morning sky. but since
1880 they have been seen at Berlin
only between midnight and dawn. They we're
intensely bright at times In 1885 and 1885, but
their splendor has faded. and II 10 probable
that but few more opportunities to observe
them will be afforded. For some reason they
have been hardly noticed outside Of Germany.
Holland. and Russia. l do not recall any OBJ
servatlon OF them In this country
Their appearance Is that OF transparent
fleeces and strlsted bands floating at an enor-
nous height above the earth and shining gen.
erallJ with silvery light slightly tinted, at
times. with blue or yellovish red. They ap-
pear long after sunset and long before sun
rise. In the evening the shadow OF the earth
gradually hides them. beginning at the TOP.
while In the morning their visibility COM
mences at their highest point and slowly APP
proaches the horizon.
The elevation Of these clouds is one OF the
most surprising facts known about them.
They are as careful measurements have
shown not less than f1fty miles above the
earth ten miles higher than the upper limit
OF the atmosphere as IL was formerly given in
some school books But We now know that
the atm os phere Ia still dense enough TO pro-
duce effects perceptible to US at far greater
heights than that. Meteors rushing into Il take
FIRE through friotion at An eleyation as'preat aa
100 miles at least. Observations during eclipses
OF the moon have sbown that the earth's
atmosphere at n height Of nearly 300 miles IA
Of the suns heat from the moon. II is eyi-
dent. then. that there mar vet b. enough air
at height o, fifty miIes to retard the fall of
such excessiyely minute and I'm pondernble
particles as the luminous night clouds are
composed OF. The tenuity OF these clouds ia
suficieutly Indicated by the fact that. vb,n
shining with their greatest brilliancy. they do
not Obscure the stars seep through them. In
this respeo, tbsv rsssm bls tho tails n, comets
which are about the most oompletely sub.
tilized ana uncomnacted Of Ali tho material
pbenomena known 10 us
Yet the fact Of their qr,dua, d,.anne.r.,oa
.tt.sts that tbssa cIonda ar. ei,har ..ttIIno
down tovard the sursace n, tba s.rth ana
minoI,no vi,b On. orosa.r dp.t mi ,rnnri,J..
tbst rend.r turhid tb. iower .trsta =, tha a.
mosnbera in which wa live. or olss ar. ss.
Gaming In som. m.nner from tha vicini,v a,
the planet n their hsieht ver. .s great as
% oO0 mile. In .tead of ,,tv ile. then q could
ba sbovn that tbev might ssc.n ma th,opob th.
.fyecta a, oen,r,,ugai ,orca OWN 20 oor+.In
.nnaaron... indic.tjro an .,oaad,r o,v I'D,
motion of The Iuminou. cloud. n ba. hoan
int.r.t.I,or r,ediu,n On brou,h whi.h ,ba ..r.n
"a rusbing and are brusbed .wav 40 70 .nsst
n. ~ ,orr.d NV migh,x w,nd pn,
IN renIv 10 mi. it ia onIv n,cass.r,
20 ssv that . r.s,atanca an "A, oian, 10 nrodn..
.r.h .fy.,t. would suroIv ..nsa . n.,c.n,ihIs
,s,.rd.tion =, en-. r,nt,on =, ,h. NJ. = ~. i. ID
NJ The nariodical cometa
Trnon IN. vhoI. th.n !. q. nroh.h,. that ,h.
nsrt,cl.. comnosing ,h.s. - ',s,.r,nrs .,ords
Az. hsino dis.instsd ,hroneh th. .Jr ana .rs
sIoxIv sattlIno .srthvard That h.ing ,h.
cs.s n 4. not .Itoostb.r IN, no.sthIa On at sor.
NJ than NAV va, mas. tbrough our Iuno. or
NAV already h.y. dons so In this visv q, tb.
ease tbaouestions of what ara the e,oud. cor-
no.sd and vbencs have thax orio,n. .t.a a.
aume A p.culiar intere.t. Arc thsy ~ FAR.
restrial or oslestial oriein7 Can th.y exercise
a deletsrious effect upon the inhabitants ~
the eartA7 In regard to the latter ousstion IL
IL may be said that tho quantity of mat
ter contained in these cloud. must bs
40 slight in com mparison with the vbole volums
~ ~ ',s sno ,S' na."e au'oun' VI ihpuIs
would be in1niteaimAl and conaaouantlv In