The Wheeling daily register. [volume] (Wheeling, W. Va.) 1864-1878, 1877-09-14
MARS AND HIS SATELLITES.
Chicago Inter.Ocesn.

Chicago Inter Ocean.
The planet Mars is just now conspic'
uous object in the evening sky. lndeed
four brilliant planets may be seen st
nightfsll, Venus on the western horizon
and about to set, Jupiter, a little Past
the meridian, and Mars and Saturn on
the southeastern horizon. But Mars
beams, at present. brightest OF them all.
Through good telescope, even o. moder-
ate size, It's stretch OF land and water may
by seen with considerable distnctness.
The great area of polar snow a!so shiL es
out in sharp contrast with the prevailing
ruddy aspect of the planet. The unusu-
ally fiery appearance OF Mars in this
time OF war almost justifes the ancient
mythology, and, were Lord Bacon alive,
might confirm that learned worthy In
his leanIngs toward astrology.
1t Is the recent discovery OF pair OF
satellites which gives interest to Mars At
this time In the line of pure science
the discovery has done one or two things
worthy of note. 1t has confirmed LIE
| Verrie's calculations OF the mass and
perturbing force of Mars and has added
not SO much new laurels TO that great
scholars sttainments as new triumph
to exact mathematics and their sppics.
tiOn to the problems of celestial motion.
1t has rendered probable the theory that
| all the planets have satellites, and that
perhaps the satellites themselves have
still smaller secondary bodies REVOLVING
about them; and, more especially, it has
lnsugurated new period in discovery,
by showing that the new and larger re-
| tractors which have been invented IN
this country and in Europe within five
ing old difficulties, in practical
optics, and making real con-
quests over distance. The small dimen-
SONS of these new satellites only add
force to the theory that the inter-plane-
tary aud inter-stellar spaces are teemlng
with cosmicals bodies, larger or smaller.
1t is doubtful however, if the rapid con-
| cluslons OF the astronomers will be justi-
| fed IN all respects by further observa-
lions. Professor Watson, of Ann Arbor,
estimates the larger satellite at I miles,
and the smaller at p miles in diameter.
| He is reliable observer and calculator,
and is probably correct, but it is difficult
to conceive OF any object of even the
larger dimension being visible so lar
| AWAY. At the distance of 35,0OO,OOO
miles-supposing that to be the distance
of Mars from the earth ut this tlme-a
| body would need 10 be- 10 miles in d.
ameter to measure one second OF an arc.
at this distance u square measuring u
| .,.,.,I IN ,ab HipaniInp Nupnln no IarUp
enough to ContaiA q thousand satellites OF
the supposed dimensions OF the greater
one. To see body of that size would be
equivalent TO seeing an object an inch In
diameter at n distance OF ll6 miles, or 10
seeing fre-hy's phoSphorcscent parts,
the FREELY being AT Lake Forest and the
observer at Hyde Park.
The measuring OF the size OF body
by the light II radiates-the course pur-
sued IN estimating the dimensions OF the
| Martial satellites is good enough under
some conditions. 1t is, however, 50 eX-
posed to fallaces that one may be very
easily led astray. For example: Mars
being OF given diameter, its light
NAV be put down at any gwen
figure, the light OF u body
near Mars being estimated TO be so
much MS compared with that OF Mars.
We are supposed to know the diameter
of that body. There is danger OF error,
and also lallary in the reasoning. The
danger OF error where no phoLometer Is
actully used, but only the judgment o!
the best observer arises from defect OF
the eye itself, or rather from its inaptltude
for making such sort OF comparison. The
eve is variable instrument, instantly
adapting itself u light or darkness, and
therefore is disqualified in degree Tor
measuring light 1t is as though quart
measure should enlarge or shrink as you
put more or less INTO 1t.
The Lacy lies in the supposltlon that
the relative degree OF light i'll two bodies
will give strictly their relative dlameters,
for light gets some degree OF intensity
from light and loses from the ,oss OF iel-
low beams of light. Hence, /: the
satellite OF Mars shines with II light OF
one eight hundredth part OF that OF tn"
planet, very likely its diameter may be
more than one eight-hundreth part OF
the primary. At any rate it is safe to
give good, fair margin in such calcutta
| tons.