New-York daily tribune. [volume] (New-York [N.Y.]) 1842-1866, 1859-12-03

the difference in case Of the earth being only twenty
seven miles
Notwithstanding this prodigious bulk, Jupiter ro-
tates upon his axis in about hours according TO
which, body on his surface Aes round and round at
the average rate Of twenty thousand miles per
hour, about twenty-seven times faster than eorre-
Tondng body the earth. When the direction Of this
motion comedies with that of its orbital progress the
combined speed is not much different from that of the
center Of the earth in It's orbit.
To the naked eye the planet appears with a diane
ter about oneforieth that Of the lunar Disc that
telescope magying forty times win present it in the
field of view about large the full moon. A mag
nifying power Of four or five is sufficient 10 raise
a sensible disc. With power of thirty the most
prominent belts and oval form visible; though 70
make ont the fainter lines which girde the sphere,
requires power Of two or three hundred, beside
favorable atmosphere. In such glass the planet pre-
sents series of brownish-gray sreaks reminding one
OF stratus clouds which often lie along the horizon, in
the morning and evening. OF these areaks, whose
general direction is parallel to the planets equator,
there are two more conspicuous than the rest either
side of the equator being separated by bright yellow
zone. These principal belts generally found TO ex-
tend al round the globe as they continue visible during
the entire axal rotation. Toward the poles other par
alle lines are visible, closer and closer together till
they finally coalesee near the north and south points
These remarkable appearances supposed TO be the
effect of prevailing winds and atmosphere so loaded
with clouds as almost entirely to the face of the
planet from our view. Their permanence of form,
position and arrangement very striking, indicating
a climate in every zone ofgreat equabity. Stichanges
are apparent progressing slowly, completely altering
the face of the planet in the of few months.
The peculiar distribution Of the belts is probably due
to winds blowing, ike our trades constantly in di
rection parallel to the equator and having far greater
steadness and intensity than those which blow in the
equatorial regions of the earth from the fact that the
diurna motion is vastly more rapid.
A subject of even greater interest to the astronomer
than these remarkable bands the system of four sat
elites which the telescope discloses They were
among the pioneer discoveries of Calico with the first
telescope ever directed to the heavens. He at first
took them for fixed stars, but he corrected bis
error by discovering that they revolved round the
planet in periods respectively Of and three fourths,
three and half, seven, and sixteen days. This rapid
iy of revolution is very remarkable and must present
to the inhabitan of Jupiter if such there be- noctur
nal scene of the greatest beauty and vivacity-one
moon going through its round of phases in four Jovan
days. second in eight and half third in seventeen,
and fourth in forty. In size they appear from the
surface of the planet the nearest will nave disc not
much different from that of our moon, and the others
smaller In consequence of a remarkable law, accord
ing to which the three first satellites sustain to each
other a weknown physical relation, these can never
all be absent from the armament Of the planet at the
same time nor be in the phase. Thus the Jovias
will often cleaning in the west just after
the going down ofthe sum- silver crescent anotherjust
risen in the east full rounded Disc and third occu
pying an intermediate position and phase-uniting TO
form spectacle of the most engaging beauty. From
the fact that the three first satellites lie nearly in the
plane of the planets EQUATOR and the fact that the
planets orbit nearly comedies with the plane of the
elliptic a singular result ensues the three ecpsed
to the inhaLiant of Jupiter at every revolution and
eclipse the nearly as often, making together many
thousand eclipses in the course Of the Jovian year.
When Calico became aware of the spendor of his
discovery-that his Medieean Stars, he called them
in honor of his ilustrous patron true satellites
he announced il to the world with becoming pride
and enthusiasm. The following is the title of the
work, containing the account, published at Venice in
1910:
The Sideredl Messenger, announcing great and
very wonderful spectaees, and offering them TO the
consideration of every one, but especially Of phloso-
piers and astronomers which have been Observed by
Calico Galiei, &c. &c. by the assistance Of a per-
suectye glass lately invented by him; namely, IN the
face of the moon in innumerable fixed stars in the
Milky Wav in nebuous stars, but especially in four
planets which revove round Jupiter, at different in
iervals and periods with wonderful CELEBRITY; which
hitherto not known 10 any the author has recently
been the first detect and has decreed TO call the
Medicedn Stars.
Apart from its intrinsic interest an incidental i'm
por4ance attached at this discovery. The hello
cenicheory of the planetary motions was then strug-
Cling for supremacy. The doctrine of Hipparchus and
PtoIemy, which made the earth the fixed center Of
revolution for all the heavenly bodies had for nearly
if not quite twenty centuries held undsputed sway.
The new doctrine of Copernicus which fixed the sun
at the center of motion and attraction, had not yet
gained substantial footing though more than half
century had elapsed since its publication. Proof of
this is furnished by the circumstance that the Church
that most sensitive of insttutionswas not sufficiently
informed of the doctrines to find in them the her
esy for which afterward when these had come TO be
more widely and publicly propagated and discussed,
greatly in consequence, it is likely, of the telescope
discoveries of Calico prosecuted the Tuscan philosc-
pher Thus the sudden and unlookedfor revelation of
Jupiters satellites was opportune. 1t presented to the
eve of the observer miniature system, precisely anal
ogous 10 that which Copernicus had declared belonged
to the Sun. -Four little planets revolving round their
primary in orbits so small and periods so short that
they were easily watched through every phase Of their
lunation. Nature was caught in the very act. The
confirmation of the hehocenric hypothesis was com
pete.
But not only were these startling revelations of the
telescope important TO the astronomer: they have
deep interest for the moral philosopher as we'll Hith
erto the heavenly bodies had been considered to be