New-York tribune., 1874-02-11
~, pRocToKs THEORY ABoUT JUPITER


y. Msgditor Of The Tribune
s,p.M Mr. Proctor, in an article in The Popular
s>s,r,, Konnly for February, selected from me fo"
Ro.s.ce Rer,esc and his lectures at Association nan
sakes an assumption with regard to the atmosphere"
;nritar which seems Inconsistent with an admlssoh
made in a subsequent part OF the article ahnueu 'o
EseaAing OF Mr. Mattiou's conclusion, he remarks
faisy agree with him in regarding 1t as Ie'So""'o ~
tveTy planet has an atmosphere Whose n"oe o
sponds with the CT the planet 1t Sutonuus. " W
make such assumption 10 the case " '"pl'o-,
aTnye al conclusions closely resembling tho-o 70 "h'n
I have been led by the above process oi teasolus'
viz that the pressure OF Jupiter's atmosphere az MS
surface must bebetween 200 and 500 unes t' oi our
atmosphere in order 10 possess densiW eqii " 'ho
aen.ity Of one fourth OF our atmosphere Co "
seven miles from the surface OF the eaf'" Ns u
.e the correctness Of this conclusion Inc mass Oh
-. =, oee ,rros that az the earth; hence according
. ~, ahove assumption atmosphere should be sss
e, that az our globe But this mass AT the SURFACE oi
Juper " IN weigh about q tunes as mueb az NJ Tue SUI
face az the EARTH gravity OF Jupiter beng tha muen
Greater than the gravity at the earths surface Inc
entire weight Of Jupters atmosphere therefore will lie
n, s4 times that of the earth But the surface OF Jupi-
g., 1as times that OF the earth The pressure therefore
on each square inch will equal the entire pressure
divided nv this surface, or about seven Amospheres
Now as the pressure of Jupters atmosphere oonoeu
through every descent Of 2t miles, az that OF the
.artbs is, for every 81 miles, we find the pressure III
seven nes from the surface very heary equal TO the
pre,sute of the earths atmosphere az TIC same hight
Hence the cloud system OF Jupiter must resemble that
Of our earth provided the cloud material he similar on
the two planets II the cloud matter possesses DENSITY
proportional the density OF the planet II will ne one
fourth that Of terrestrial ceuds and consequently the
cloud eDvelop VIII be forther from Jupters surface
il from the earth. The limit of this atmosphere
sabout G. mes,hs being the point where the cen
trfuga aud oenipeia forces balance each other for
particle revolving about Jupiter in the time the planet
makes one revolution This is the method employed by
apace 10 ascertain the hight Of the suns atmosphere
OF the surface IL will possess extreme tenui
Jupl;ors atmosphere, therefore, may he adapted to
animal hfe differing but little from that Of our globe
The assumQton Of MI Proctor therefore that Jupiter
must be n heated state to give sufficient eiaslelS 70
surface seems inconsistent both with the analoees OF
.ne iiues anu t-e SuDlsson 4eb 4nt a., .hsn ansoS
ical TossOu admits Of 10 would be more proper 10
,eek the cause IN the greater evv of the coudnaera
MI FrOctoTs argument for the heated condition OF
Jupiter drawn from hls small density loses much OF s
force take into account the density OF hs sate
htos ratios OF the density of Jupiter ana his at
tendaus, taking them in order beginning Win the nrst
are l2 Is, 81 10 II the small density OF Jupiter u
owing TO his heated condition what shall we say OF the
sIil smaller denses OF his moopsi According 70 MI.
ProctOrs theory OF "accre0n presume ne attributes
The heated state Of Jupiter to hs greater power ~ draw
mug IN the moteorc masses by whose concussons on the
dynauiCa theory Of heat. high degree OF heat IL de-
veiOpeC But Just IN proportion as ths cause operates
10 make Jupiter more rare VIII IT operate 70 maze hl'
attendants more dense In other wofds VINE tis ialn
lily OF worlds is passing through the rch nete0rc pas
turagC space, the Wouiu
poorly in presence Of TINS celestial hehemOth III
fact il IL admitted Mr. Proctor at least with respect
the fourth satellite density II onesfxth that O
Jupiter that the density OF the secondary u not OWNS
20 the cause which produces the small density o.
primary He observes n at the satellite passing OVe
The disk OF the plauet appears black spot the IN
ference being that while the moon is Opaque SIMPLY re
Meeting the suns light the planet adds t'
the Tef1cted light lts own radlance; Il
seems oer that whatever the condition OF Jupiter
she satellites are cold, opaque bodies. The question
ther arises Why tins small comparative CeDsiyi Cal
come other conclusion than that I0und IN OnI
books ASTRONOMY. w. that the naelltl OF JoNIal
system possesses less density than the terrestria
plaBets4 This conclusion does Dot deny tbat Jupiter
possess elements TO our earth af TeVedeo
by the spectroscOpe, hut points to combinations ana
proportions differing from those OF our paIeL AssuI
Ipg the identity of Che matter o. the earth and moon
also the identity of the OF the JOyan system
and reasoning from the relation OF the density OF oul
earth ana moon compared with the density o Jupiter
and hs fret attendant, might prove JuplterlO Ut
colder than the The density OF the eartn ls Twice
that % his first satellite The satellte ls cOu DOdy
hut Jupiter times dense hence he must be pro
poroDatcly colder than the earth In order that h'
density OF the earth be IL tunes thdt OF the moon
lt dimensions must he considerably decreased auu eoh
nequeuty It's temperature. $4,000. -
This conclusion OF Will be modlned 10 com
extent by the the ratio OF the density AT th
surface and at the center ~ greaHr u large pahe
earth and moon owing part TO tins Tact rathe
than any great difference OF temperature The elhpt
city Of Jupiter compared with that OF the eartn how
shows that the law Ot increase OF density r0I
surface center OF the earth does not differ from IN
law OF Juper's of density sufficiently 20 vat
the above conclusion. Until Mr. Proctor prOduc
stronger arguments than he has vet presented IN supper
Of h theory should prefer with Brewster 10 cOnsde
"JHpeT the nOblest OF Inhabited worlds" b. p.
B0kOksS, " j., Feb. 5, 1874