THE WEST SHOKE.
January.
68
MAItS AND HIS MOONS.
We take the following abstract of a paper
read liefore the California Academy of Sciences
bv Pro! John LsConte, from the Mining tind
8ckntU Prm i
There is no member of the solar system, with
the exception of our moon, whicli can lie Studied
under such favorable circumstances as the
planet Mara; for, although Venus, when in in
ferior conjunction, is nearer to us than Mars in
opposition, yet Venus, at this time, turns her
darkened hemisphere towards the earth. More
over, although Mars docs not appear so large an
object in the tslssoopC as Jupiter, yet he is in
reality seen on a much larger scale, not only on
account of his much greater proximity to us,
but because, bciiig likewise much nearer the
sun, his surface is much more brilliantly illu
urinated, so that a much higher telescopic power
can be advantageously employed. Accordingly,
over since tlie invention of the to lesco pe. Mars
has been a favorite object of observation. The
largest and most powerful instruments have
Iteen employcii to scrutinize mis planet, ami
the varied physical details of its surface have
been most carefully mapped by many astrouo.
inert.
When, therefore, it was announced-, a few
mouths ago, that the American astronomer,
Hall, hid discover. id two satellites belonging to
Mars, we ought not to be surprised at the aston
ishment with whicli the news was received by
the sciciitilic world. Moreover, there can lie no
question that for more than two centuries past
astronomers have recognized the probability of
the existence of satellites to this planet. In
fact analogy would load us to expect that Mars
would be fnrnilhed with one or more moons;
for, being situated at a greater distance from
the sun t Kan the earth, it seems more especially
to need such luminaries to cheer its dark nights.
Under the Influence of these anticipations, the
astronomers who have so carefully studied the
physical features of Mars, have doubtless been
looking for these satellites. In fact, many of
them have contended that the failure to dis
cover them is not by any means a conclusive
proof of their non-existence; since Murs, being
a very small planet, wc might expect his moont
to In- proiHirtioually small, in which case they
might eeOMM detection by the telescope. Thus,
for example, the second satellite of Jupiter is
only aliout the forty-second pert of the diame
ter of the planet; and a satellite which would
only Is! the forty-second part of the diameter
of Mars would be about 100 miles in diameter.
At the least distance of the earth from Mars a
satellite of this dimension would subtend an
angle of less than one-half of a second; so that
even in the most favorable position of Mars,
powerful telescopes might fail to reveal such
an object especially if it do not recede far from
the disk of the planet,
This state of doubt and uncertainly in rela
tion to the lines turn of the existence of Martial
moon afforded legitimate game for the satirical
writers of the last century. Thus, Jonathan
Swift (more familiarly known as Dean Swift),
in his "liulliver's Travels," published about
17-','. in giving an account of the extraordinary
race of abstract philosophers who Inhabited the
11 Floating Island " called Laputa, Informs us
that: "They spend the greater part of their
lives in observing the celestial bodies, which
they do by the assistance of glasses far excell
ing ours In goodness. for, although their lar
ges telescopes do not exceed three feet, they
magnify much more that those of urn with us,
and show the stars with greater clearness.
This advantage has enabled them' to extend
their discoveries much further than our astrono
mers in Ktirope; for they have madea catalogue
of 10,000 lixed stars, whereas the largest of
oura does not contain above one-third of that
number. They have likewise discovered two
hsser stars or satellites, which revolve about
Mars; whereof the innermost Is distant from
the center of the primary planet exactly three
of il diameters, and the outermost live; the
former revolves in the space of 1(1 hours, and
the latter in Slt so that the squares ol their
periodloal times are very near In the same pro-
non with the ounce ol their distanoea from
the center of Mars; which evidently show s them
to be governed by the same law of gravitation
that innnenoes the other heavenly boaics,''
About 'Jo years alter Swift wrote the fore
going, that is in IT-VJ, the celebrated Voltaire,
apparently In Imitation ot "Gulliver's Travels"),
cuttingly ridicules the pretensions of the class
of rcaeoners who found their conclusions ukui
analogy. In one of his satirical tales Micnuu
egfts, au imaginary inhabitant of Sinus, is sup
poncd to make a voyage of discovery through
the coter systesn in company with a oeniseu of
Saturn: they philosophize as tin y go. Approach
ing the planet Mars, UicrotnegaS and ins com
panion plaitilv descried two moons acting as sat
ellites to that bod moons which have cer
tainly cacaped the ken of terrestrial astrono
mers. "I know perfectly well," continues the
author of the tale, "that Father Casts! lan
astronomer of the tuueiwill write, and write
iitlicielitly pleasantly, too, against the exist
ence of these two MOMS) but I appeal against
his decision to logicians, who reason from anal
ogy. Those excellent philosophers arv per
fectly aware how difficult it would be for Mar
a pUiiut so far removed from the mil to get
on With leas than two of these satellites.''
ttXuvreS de Voltaire Micpunegae, Chap,
How completely the rO00ftt discovery of the
American astronomer ha "turned the tables"
on tin- rsMwned. satirist of the last oeutury I
The I'M mulls ol those excellent pluloatihere"
who founded their conclusions upon analogical
reasoning, although aluuilcring in the douiaiui
ol the unproveii for more than two centuries,
have at last Ikhui venlied by dirvct observation.
arm mi. naoovnt or niK saftURsa was
hot MKit ssjoarn,
As till' mooua o( Mars are vry small objects,
it is only under the most favorable circum
stance that they caul' seen by the moat pow
erful teleacow. Mara is iiearvat to us when
hi opwition occurs when he is near hia pri
helion; and the grvateat oMible prxiximity ton
occurs w hen Mara n in opposition in )tenhrlion
and the earth ia in aphelion at the same time.
1 tie oppositions oi Mars near perihelion occur
at intervals of 15 and 17 years successively. A
very good opposition occurred in I8(i2; and a
great many distinguished astronomers embraced
the opportunity ot scrutinizing Mars w ith the
aid of excellent instruments. A still mure fa
vorable opportunity was presented in the sum
mer of 177, when Mars was nearer to us than
it has been since 840i It was at this time
that Prof. Asaph Hall was fortunate enough, by
means of the new L'tiiueh refractor of the Naval
Observatory at Washington, to discover two
moons Isjlougiug to this planet. It is true that
this was probably the lirst time that so jsiwer
ful a telescope had ever leeii directed to the ex
amination of Mars under similar favorable con
ditions; yet, it is a significant fact, that since
the announcement ol the discovery the satellites
have been detected by means of telescopes of
more nnslcrate power. I tie secret ot 1 rot.
flail s discovery seems to have consisted in lie-
vising tllu meaiia OJ cutting off, from the Held
of view of the telescope, the glaring light of
Mars. In like manner, M. Henry, of the ob
servatory of Paris, on the l'7th of August, 1H77,
was able to see the satellites when Mars was
screened from view. These diminutive moons
nestle so closely to the planet that it is dillicult
to see them in the blaze of light reflected from
Mars. Had similar means of screening the
planet been employed, it is probable that one
or both of these satellites might have been dis
covered in ISIi'J.
DISTANCK8 0? MTILUTES IBOM center Of MASS.
The distance of the inner satellite from the
center of the primary is about 2,73 times the
thi! radius of Mars; that of the outer one about
6,840 times the same radius. Assuming the
liaineter of Mars to be about 4,200 miles, these
lislances become, respectively. o,7;tlf and 14,-
170 miles from the center of Mars. The near
!st satellite of Iiii.it. r is distant about six times
the radius of the primary, and the innermost
saicinio ui qmiuh is oi -;.iiu u lino; awn mi mi
three times the radius of that planet.
1RI0M OV BIDKBJEAL llKVoi.noN 01 TO I laT
ELL1T1W (IF MARA
I'rof. Newoomb rives, for the period ol revo
lution of the iniiur satellite around Mars, about
hours, or 7h. 89m, and 'M).-2 hours, or
80b. 1 "nn. as that of the outer moon. Both of
them, like our moon, revolve around the pri
mary from west to east. .Mara rotates on its
from west to east in .U'J.t Hours, or :mii.
37m. 28s.) this is the duration of the Martial
day, or the time occupied bv a Htar rising in the
east in passing over to the western horizon of
the planet. We havo seen that the period of
illltloll.il the Miner satellite is leas, while
that of the outer is greater, than a Martial day.
It is evident, therelore, that, as wen troin the
surface of the planet, the apparent motion of
me satellites win oe in opposite directions, uiu
r rising in the west ami setting m the cast,
the outer like our moon), rising in tho east and
setting in the west. This anomalous condition
f things must have greatly perplexed the prim
itive astronomers of Mars, and probably led
them to the invention of cycles aim epicycles to
account for these appearances.
It Pillows mat tin) phenomenon oi two moons
meeting in inid-heavens will le no unusual oe-
rorrence to cne observers on the .surface ot Mars.
The apparent motion of the fixed stars from
BSSI to west, produced hy the rotation ol US
planet upon its axis, is at the rate of 14.62 per
hour. The real motion of tile inner satellite
among the stars from west to eaat is at the rate
of about 47.06 per hour, while that of the
outer one is at the rate of 11.00 per hour.
Hence it follows that the apparent motion of
the inner satellite from west to east across the
heavens to an observer on Mars, w ill lie at the
rate of about 32,44 per hour, while the appa
rent motion of the outer moon from east to
west will be at the rate of nearly 2.72 per
hour.
It likewise billows from the preceding calcu
lations that the time elapsing between two suc
cessive meridian passages of the inner satellite
will Ik' about 1 1.00 hours, and the time elapsing
between two successive conjunctions of the
inner with the outer moon wul be about 10.24
hours ; consequently two conjunctions w ill occur
in less tune than it takes for Mars to rotate on
its axis, or than a Marjial day. This satellite
completes more than three orbital revolutions in
a Martial day.
As the apparent motion of the outer satellite
from east to west is at the rate of only alktut
'.'.7'.' Per hour, it is obvioUS that the time elap
sing between two successive meridian passages
of this moon willltc about 182, SB hours; so that
there will be no less than Ifl conjunctions with
the inner triOOU in the course of a lunar day. It
is likewise c ident that the outer satellite will
frequently is- abovs tha horison of Mars mors
than nil hours, during which period six eonjnnc
i n- with the inner mav occur. Moreover, at
the outer moon will go through its cycle of
phases in a little more than :u) hours, all of
these changes inn 1h' accomplished wlule It is
ftboVS the horiou of the OOOOfTSr OU the surface
of Mara.
FARBOT BUOKITVDI Ot MAM SI BggJI mOM
Ills laTMXRBS.
The apparent diameter of Mirs, as seen by
an oliaervcr on the inner satellite would Ive no
less than 41. S . or SDOUt 1$ times the apparent
liamcter of the sun as seen from the earth:
ind from the outer moon the diameter of Mars
would subtend an angle of I67 Of about 81.9
times the apimrctit diancter of the sun as seen
I us. Of course the apparent areas of the
lik of Mars, its seen from his two satellites.
would 1 in the ratio of the piarcs of these
nun i Iters, That is, the apparent area of the
liak of Mars, as seen from his inner moon.
would be 8, 187 1 and from the outer 980 times
the ippareol SXIS of the solar disk, as set ii from
the earth.
from the innermost satellite of Saturn, the
.liatnuter of the primary would subtend an aiiide
of 85(8 from the nearest satellite of Jupiter,
thd diameter of that planet would subtend an
angle of IS.ti ; and from our moon the earth's
liamcter w oiim siiluemt an angle ot leas i nan . .
Al'lMKKM KAOXROM or US lATHXITlS AS
SSK rHOM MAK.
Aatronomera are, aa vet. ignorant of the rva.
maguitude of the Martial aatllita: but, aatum
,.. .i, ,.t" r),.m to le iihi miles in diameter,
it is easy to calculate their apparent magnitudes
as seen by an observer on Mars. The inner
moon being 5,733 miles distant from the center
of Mars, would, wtien in tne zeuiui oi wc
observer, be only 3,fi33 miles distant from the
surface of the planet Hence it appears that
when this satellite is seen in the horizon of the
observer on the surface of MarB, its diameter
would subtend an angle of aliout lil)m., or nearly
twice the apparent diameter which our moon
presents to us; but, when it is in the zenith of
the observer, it would subtend an angle of
94.3m., or more than three times the apparent
diameter presented by our moon. In other
terms, in risint: from the western horizon to the
zenith, the apparent diameter of this moon
w ould Is; increased nearly in the ratio of two
to three; anil, of course, its apparent area would
be augmented nearly in the ratio oi tour to nine.
The outer satellite would, under like posi
tions, present apparent diameters respectively,
of 24 and 28m., or considerably less than the
apparent diameter of our moon. The nearest
satellite of Jupiter (having a diameter of 2,310
miles) would, in like positions, present to an
observer on the surface of that planet apparent
diameters, respectively of 31m. ami 37 OU
BBABIMO 0 THE UKWOVKKY or MAltTIAl, SAT
ELLITES ON THE HBOLAB QYPOTHSSU,
As we have seen, the inner satellite of MarH
completes three orbital revolutions in less than
a Martial day. "This anomalous fact in the
planetary system would seem, at lirst view, to
be utterly inconsistent with the nebular hy
pothesis. According to tlria hypothesis, the
orbital periods of the satellites Bhould be approx
imateiy eijual to the rotation periods of the
primary at the epochs when the satellites were
thrown" oil' from it. The acceleration of tho ro
tation period of the primary, in consequence of
its suhsc'iuciit contraction, won m necessarily
render its time of rotation less than the orbital
period of auv satellite. As far as vet known
the inner satellite of Mars affords the only in
stance in which the rotation period of the
primary is greater than the orlntai period ot
the secondary.
It must be remembered, however, that if we
regard the rings of Saturn as composed of clouds
ot liiilepeintcutiy-revolung minute satellites,
those constituting the innermost portions of tht
inner ring must revolve in Ichb time than the
rotation period of that planet. Under tli
view, therefore, the case of the inner satellite
of Mars is Hot union
There are, however, several methods by
which the apparently, anomalous fact may lie
accounted for consistently with the nebular
hypothesis.
1. In the lirst place, it has been Suggested
that Mars may not have obtained his satellites
by means of the usual process of moon forma
tion; but by the appropriation to himself of i
couple of the numerous asteroids or planetoids
some of whicli, in their perihelion excursions
approach comparatively near to Mars in his
aphelion positions, Tim-, the planetoid called
Phoceu, when it is at its least distance nml
Mars at his greatest distance from the sun,
would only be about 11,000,000 of miles from
each other. It is, therefore, possible that some
of the planetoids, moving in orbits of greater
eccentricity than any yet discovered, may, at
some former period, have approached bo near
Mars as to have DCOOTOC permanently attached
to it as satellites.
In the second place, it is possible that
these Martial moons may have originally re
volved in larger orbits, and therefore in longer
periods than ;it ptvm-nt; imt that the rctardiui
influence of a reistitii: medium on such siual
masses, might, in the course ot myriads ot ages,
have contracted their oroits and consequently
shortened their orbital Peritsls. In tins con
nection it must be borne in mind, that, aooord-
niL' to the nebular hypothesis. Mars must I
vastly older planet than the earth; so that this
retardation may have been in progress for on U3
;U.:iil,ihlc nuiulnT ot centuries helore th
suth
Isjcanie a separate plain t.
.1. In the last place, it ib possible that .Mars
may have originally rotated, on his axis in live
or su hours; tint that the tidal rotation-rctard-ation
produced by the action of his moons
might have brought almut its present rotation
lenod. It is evident that tin- solar tides, on a
planet so small and so remote from the sun,
must be inappreciable; aud, at tint sight, the
lunar tides produced by such small masses might
lc Mipioe.l t.i lc cipi. illy iii-U'iuhcaiit. lint il
must W recollected that the tide-generating
war of a moon is (other things being equal
rersely proportional to the cubs of its tlis
iioo : so that nearness might more than com-
pi ii-. di for sinallness of moss. To bo more
pecitic: In the mathematical language the tide
generating power is in projKirtion to the
Ihaineter of Primary Mass of Satellite
i Distance of Satellite.)'
Thus, for example. let us suppose the diameter
of our moon to Ih 80 times tlie diameter of the
inner satellite of Mars, and tsith moons to be
eipially dense: then the mass of our moon
would be S.000 times that of the Martial satel
lite. Taking the diameter of the earth as equal
to twice the diameter of Mars land it is not so
great), and the distance of our moon from the
center of the earth to . 41 : times the distance
of the inner satellite from the center of Mara;
we then have the tide-generating power of our
BMOn acting on the earth, will )e to that of the
inner Satellite acting on Mars
8000
tol,
(tli!'
1
to l,o
to I, or H I to 4.J.
71478
Hence, the tide-generating power of this small
satellite, would, in eon sequence of it nearness
to Mar- be about 4 times aa great as the tide
gvner.iitng power ot our moon on the earth.
In connection with the idea of the rotation
period of Mars having, at SOtDS former time,
lioen much shorter than it is at present, it may
lie noticed that the great compression or cllip
tldly of this planet is totally inconsistent with
its observed rotation period. Moat astrono
mer estimate the ellipticity of Mara at from
1 tn '
40 00
(although some of them have
failed to detect any sensible ditfervuee in hia
equatorial and polar diameters); the ellipticity
of the earth is only Might not thisgreat
ellipticity of Mars have leen the result of sol
iditicatiou having taken place when his rotation
period was much shorter than it is at present ?
This explanation is not free from serious diffi
culties. For, if aqueous and aerial agencies
were in action after solidification took place,
they would have tended to make the shape of
the planet conform to its new rotation period
Berkeley, Dec. 86 1877.
SPONTANEOUS GENERATION.
At the last meeting of the San Francisco
Microscopical Society, a paper was read by .Mr.
H. C, Hyde, summarizing briefly the issue as
they now stand between the upholders and op
poncnts of the theory of spontaneous generation.
Mr. Hyde takes the sides of the opponents, re
lyintr on the results gained by Dallinger and
Drysdale, ot these results he oaid. in flu, foal
place, it is conclusively shown that somo form
of the monads omitted palpable germs, visible
however, oiilv with the I 30th inch aMfaBsaW
and when visible of the Bize of alwut l-200,000th
of an inch, Others were, exactly sneakintr
Mparous, endttins no oerms, but ouenimr tn
give birth to minute living tonus, while another
form ot monad emitted oerms winch the hl-IicjI
magnification failed to resolve, but the presence
of which was indisputably proven by results.
m the second place it was conclusively shown
that the different adults forms were capable of
surviving varying decrees ot heat ranging from
Ol iU-2 K.)to80' (178 F.) C, while the re
markable fact wos developed that the Bponiles
or germs were able to survive a temperature of
iw.sk l. low r.
From these facts thev claim, and iustlv. T
think, that the assumption of Bostian and some
others, that the germs of putrefactive organisms
inn -i put mi in his ouiiiu coiiuuiuus mat ueatroy
the pai mi is erronous.
W lrile this has not been actually Bhown of
bacteria (the sole organism upon which the
theory of spontaneous generation has been con
structed) it may be strongly inferred that the
bacterian germs are too minute to be observed
by our present optical appliances, and it must
1c rememliered that the monads are as much
putrefactive infusoria us the bacteria,
Itastian, from certain iufiiBioiiB, produced
both monads and bacteria. To guard against
the introduction of supposed germs, he sealed
up his infusions while boiling, and then sub
jected them to a temperature of about 300' F.
Upon opening his sealed llasks, after the lapse
of a sufficient interval, he found living monads.
Those he found were absolutely destroyed at
a temperature of U0J F. ; and upon this result,
he regarded the theory of spontaneous genera
tion, or archegenesis, as he terms it, estab
lished. While Tyttdall and others have proved uegf
tively that under certain conditions of tempera
ture, aud the absolute exclusion of possible
germs in the surrounding air, living bacteria
were never found, it remained for Dallinger and
Drysdale, with tho aid of the microscope and a
marvellous stock of patience, to actually see
that in the case of a closely allied form there
was a positive production of germa from living
monadk and that these germs, but not the
parent forms, absolutely survived a temperature
as high as that to whicli Hastian ever submitted
his subjects; and' that, after passing through
this fiery ordeal, these same germs were seen to
develop into the living, jiarcut form, and in one
instance, at least, into one of the identical form
described by Hastian, thus illustrating, 1 claim,
beyond the jsissibility of a doubt, the source of
tlie hitter's error, ami adding another and meat
Valuable piece of testimony to the general ques
tion. Ci.kasline.hs. Dr. N. H. I'oaren writes at
follows in the tTesfSfN SiOtkJoUTHal', It is true
in all coses known to us, that the finer instinct!
agree with the conclusions of lalioriniia scien-
1 1 In- research I lie ureal laws ot nature do not
jar, but show n constant harmony; and it ii
pleasant to see the clucmatiuii ot these truuu,
which may sound too grand to be mentioned in
connection with the oiieration of cleaning a
stable. We cannot, however, refrain from Mf
iring this harmony, when wo see the buy
housewife ami clean, industrious maid servant
rubbin B at floors and furniture. SUDSNU
perfectly clean, aud washing and scalding diihea
w hich we w ould at lirst sight think might be
purified much more I limply, Their initinctssK
true. You come into the room after the furni
ture has been scrullcd, and you
breathe a freaner
air, and are in fact a healthier, and therefore i
happier and better being. You eat of taeK
Indies the IihhI tastes better and it dig
better; you therefore become, from this CW
10, healthier and happier. The reason of UW
is, that the furniture receives upon its surface
the organic matter arising from all lirinj
Teat urea, which altera time is ant to lieooSK
unpleasant ami unwholesome, hvery chair,
then, and every table, becomes a source of fl
ease: everv nii ee of the wall and the ceiling aft
the same. This is especially the cose w its H
furniture most in use; every touch of the haw
ven the whitest hand ia a source of impa
rity, and that which is used most has moat new
of being cleaned. Many POTOUS lwdiea-aa
iiil's t tlieae. .doth IaLc nn these iwiTf
groat abundance, and sometimes retain the'
much as not to give out any jicrceptible q'
tity until thev are very much tilled. WS J
this to be the case with carpets, which do art
till after sometime become offensive and BsHi
but when they are so, are very difficult tod
The process of cleaning ia too often oinfino
beating. It is to tw hoped that washing of cf
ets will become more general. Until Oua
the case, we shall never get ijuite free from'
unwholesome mustiuess of aome of our tloora
Tub financial troubles among the fine
lreler of the Kentui ky Wue gnu "t"7
becoming wiileajirevl. The (DBotJtJ "J
ome time huo with the failure of R ,,ro0
Son, with luhilitiee t over SWO.l"1- J
hu oorapHoitad matters to ueli an citeottW
learly all the leading tinm are involved.
I