Essex County herald. [volume] (Guildhall, Vt.) 1873-1964, 1880-06-18
ASTRONOMY.
LECTURE, NO. 6.
BY H. A. CUTTING, PHI. D.
JUPITER, THE GIANT WORLD.

Of all the floating bodies that COM
pose the celestial attendants OF the sun,
to which archipelago the earth be-
longs, and of all honored planets from
the renotest ages of heather antiquity,
and consecrated also to that mighty
king of gods, and men, Jupiter stands
forth to our gaze as the namesake of
that powerful god, the most colossal
world. The circumference OF this I'M
mense world called Jupiter, is $780, 900,
900 of miles, and its volume exceeds
that of earth by 1884 times. If placed
at the distance of our moon, it would
occupy more than 1900 times the space
our moon occupies and yet, this i'm
mense globe travels through space. ac-
companied by four satellites at n mean
distance of 496, 100000 Of miles from the
sun, a distance more than five times
as great as the earth's distance from
that central luminary, and yet it is
hurled around this immense orbit at
the rate of miles each second. Even
with this velocity which carries it for
ward % miles every time we breathe,
it is eleven years, ten months and sew
enteen days in completing this stu
pendous revolution. 1t revolyes on its
axis in nine hours and fifty-five
minutes, giving a velocity to its sur
face which we can hardly dream Of,
and certainly never appreciate. 1t
consequently has day, including twi-
light, of only five hours, and q night
five minutes shorter. Says the immor-
tai Kant, "If an inha Ct Jupiter
should die IN childhood, having lived
but one year on that planet, he would
be as old as a child that died here on
our globe at the age of eleven years
and three hundred and fourteen days
hundred and three thousand, nine
hundred and sixty-eight of Jupiter's
days"
Though Jupiter is so large that We
are lost in amazement when we think
of its size, it is in reality an interesting
world to study. 1t has not the density
of earth, but is in reality no more
dense than our dust or water, hence i
must be composed Of very light sub
stances, and is thought by many to b.
covered by immense clouds of vapor
rs the earth would be if the interna
heat was sufficient to convert all GU
water, oceans included) into steam
The sun being five times more distan
from Jupiter than from this earth
must present tame appearance com
pared with what we see, yet is capable
of giving the inhabitants of tina
planet, should there be such, suffi
; Gent amount of light, though mathe
matically it would be twenty-sevel
times less than we enjoy. With S,
large a world before US for contempla
ton, it is natural to speculate abou
! its probable Inhabitants ; and a Gen
man philosopher by the name @
Wolff, about 100 years ago, gave us
peculiar method of computation, t
: show even to an inch, the size of Jupi
ter's inhabitants. AS it has often beel
. published, and this shows the notoriet
: that man may give theory that ha
l no facts to sustain it, if he happen t
) be called a philosopher and thu
i speculates, will give you the sui
: stance of such computation in his ow
: language. Says he, eve are taugh
f in optics that the pupil of the eye
Y dilated by feeble light, and contrac
ed by an intense one. The light of tn
sun being much less intense for the ir
habitants of Jupiter than for us, OWN
t to their far greater distance from tn
;. star, it follows that these men hav
y pupils that are larger and more dilate
f than ours. Now we observe that til
: pupil is in constant proportion to tn
t globe of the eye, and the eye to tn
1 rest of the body so that the more til
q pupil is developed. the larger the ey,
e and the larger also the body. In orde
y from this principle or rule, to dete
t mine the size Of the inhabitants of il
0 piter, we must consider that the di
i lance from Jupiter to the sun, is to til
e distance from the earth to the sun, {
e 2G is to 5, and Jupiter is to this ligh
n with respect to the earth in the doub
e ratio of to 90. On another hand, e.
d perience teaches us that the dilatio
n of the. pupil is always more than pr,
portional to the increase of the light
intensity; otherwise body placed ,
a great distance would appear as clea
Nv defined as another placed neare
The diameter of the pupil of Jupiter
inhabitants, then. is.to the diameter
our own in a greater proportion tina
= 5 to 49, Let us suppose it 10 to 26, (
d to 10. The usual hight of the earth
e inhabitants being about feet A inche
10 we conclude the inhabitants of Jur
n ter to be fourteen and two-thirds fee
o Now this was the size Of Og, king