Evening star. [volume] (Washington, D.C.) 1854-1972, 1877-10-27
WHAT OUR ASTRONOMERS ARE DOING
Recen, Observation. AZ the observat,rr

or late months many more persons than
usual have visited the Naval OBJ serva;ory
TO view the hea' ems through the telescope
hoping to obtain 2limp,e OF Mars sa,el-
lites. Every one of them has undoub. eily
been struck with the dilapidated co1dit, on
OF the building when Is made to answer ~ g
purposes OF 8 National Observatory. TIE
scientific work done there is OF great impDr
snce, and the many valuable observation
ana recent discoveries are wine Sses of the
excellence OF the work. II is but lust thai
the building should present an appearance
worthy OF line work done in IL. Toe struc u G
was not originally intended for an observe =
tory, but only for depot for charts and in
stIUments.
FCGs AND MALARIA.
The lCca 90 Is very bad and Is unfayora
bic b, III for the work dOue and the health of
those employ ed. TIE building is situated
very near The pestilentlal liver marshes, aud
near Y every one who has been employees for
any length of time there Is an annual sufferer
from chills ami fever. Tue foss which so
frequently rise from the river materially iu-
teIiere with the success OF oh sci vations Ia
the winter this partly cOnsesled vapor gives
very unsteady position 10 the stars when
viewed through TIE telescope.
JARkISG FROM TRAVEL.
The site becomes more Objectionable as the
travel in the neigbbOrhcOd Increases, AS IL
causes slight Earring, which interfereS with
tbe accurate and delicate arrangement OF the
Instruments. 1t would be an Impossi bIlity
to make the building fire proof, yet a fire
there would be likely TO destroy valuable
properly s"d reco. dis. some of which could
no, be RI pl3 crd. II is the earnest wish of ali
c0nnoct with the institution TO be moved
any where out of the marshes.
OUR ASTRONOMERS.
Professor Simon NewcOmD is an aStrOnO-
mer OF whom America is Justly proud-who
is not only known here as an able writer and
thinker, but whose reputation IN the scientific
tirement of Professor Coffin, last month, he
was placed in charge Of the Nautical A6Rd-
nae, The publication of watch is of great i'm
Ioriance. For a long time he was engaged
in making reductions from and a discusso lou
upon the observations of the moon before
40, including an accurate determination of
the secular acceleratiOn of the moons mean
motion. This work he has finished and II is
nov In The hands of tue printer. Prot. New
comb has charge of the publication of the
reductions of the transit of Venus of a. The
measure ments are nearly completed now,
and the reductions will probably be closed
up in a most approved manner before many
months. Prof Hardness has been engage
with Prof. Ney7cOmo 10 this work. Upon il 3
completion Prof. Newcomb's connection
with The Observatory will cease, and he will
devote his attention wholly TO The Nuuicdi
almanac, unless some new field of observa-
tion snail claim it. The commission autho =
lied by Congress to make observations of
the transit of Venus now consists of Admit
raj Rodgers (president); Prof Henry, OF The
Smithsonian Institution; G. 2. Patterson,
superintendent OF the coast survey: Prof
~ w
ness.
PROF. HALL
has bad charge for some time Of the large
equatorial telescope, aud the receot discov.
cry of the moons of Mars aud his many
noted 90. eIvatiOns show that he has made
the most OF his charge. He was chief OF one
OF The parties inve Stigating the transit of
Venus, in 1874, aud Was StatiOuI at Wiati-
wOstOk, siberia, and his party was among
the most successful. Prot. Hall has recantly
made some able publications il the AstTOnO.
mische Mach icIf.H. One was upon the rot l..
tion of Saturn, determined from 90 .ervarioas
made with the large telescope, Ia which he
was materially sisted by the sCJyefy
last Deem Der OF a small white spot an re
planet. the weather ;as not allowGi him TO
take observations OF
THE MOONS OF MARS
sil ce The 10Th instant, aud ne fears he Will
rot he so'e to s:e them again this year, as
Hey have been growing fainter and fainter
He has, noweve., secured very col seriel
or Ob. etvdtIOns, fifty Cre of toe outer and
lorty- five or SIX o. the inner place, aud rl5
fixed Their times OF revolution more accu-
ratsly. His observation S, he says, are at cu
rate enough TO last TIL 1873. ween Mars will
again he in Oppo 3itiOn, alihou sh not so favof.
obse rvatioDs then, taken Ia CpDuectiOn with
II ose alre ady M lie, viii be very valuable.
GUEsSEs OF THE ANCIENTs ABOUT MACS
MOONS.
BY the way, speaking or the satellite, or
Mars. IL is curious 10 observe how in anc ieaL
times there was suppOsitiOn, that Mars ha /
twosatelli'es This idea was probably obtain
ed by reasoning from analogy. Our earth has
moon, and Jupiter four, why should MOI
Mars, the planet between Jupiter aud the
Earth. have two? And, in the same ratio,
Saturn, next TO Jupiter, eight? More than
two and half centuries ago Kep'er. in q let.
ter to his famous contemporary Calico, who
had invented the telescope, with which ne
had made the discovery OF the four m ions o.
Jupiter, used the following remarkable lam
guaRe:
am so far from dIsbelieving the exis-
tence of the four circim Jovial planets that
Ion = for telescope o anticipate you, If POS
sible, in discovering the two around Mars,
las the proposition seems 10 me TO require
six or eighl round saturJ, and. perhaps, one
each round Mercury and Venus"
IL is possible If mo- probable that this ana.
logical reasoning was afterwards introduced
into writings as fact, as TO- instance, the OBJ
ewing of the two moons of Mars, mention ID
in ''Onlliver's Travels" and Voltaire, i'm one
of his stories, represents an iDha oitant of Sa-
turn, making tour of the planet }, of which
he gives imaginative descriptions. When the
tourist reaches Mas he sees the two moons,
and says that he knows the astronomers
Will deny their existence; but, yet 1t is
so. Their presence undoubtedly was sus-
prove their reality. The suppoSition that
they are OF
NRBULAR AND RECENT FORMATION
is Lot consistent with the time OF revolution.
The inner satellite revolv; In less than one
third the time that the planet itself does
which would Tot be the case IL the satellite
were DeDulaT.
A great part of the work at the observa-
tory, and that, too, OF fundamental import
ance, consists in mai ing observations with
THE GREAT TRANSIT CIRCLE
for liking the exact Positions or the stars by
observing the time they clC IS the merid ian,
and their zenith distances; aud these Obser-
vst;ons are made every clear night irom one
years end to the other. Prof Eastman is In
charge of the instrument, with three able as
sis ants, each one being regularly on duty
every fourth day and night. The result OF
this work Is Of great importance 10 surveying
parties at q distance, in making exact calcu-
lations. and also to the Coast Survey service,
with which continued series OF signals is
Kept by telegraph. giving great aid in deter
mining bO,h latitude and longitude. These
signals are also made with different observa-
tories for the purpose of finding accurately
the difference of longitude. With the same
instrument, observations OF the sun, moon,
and plarets are made continually to keep
the tables accurate. The work ON this In
strument is very laboriOus and uaremitting.
Toe observer is on duty all night, and IN
winter suffers greatly from the cold, for the
atm phere is of the same temperature as
out OF doors. He cannot be muffied up ia
buffalo robes, but must be no every lew mo
ments to record observations. PrOfssso
Yalpall is still working on the old transit,
ard mural circle. making re observation
for the star Catalogue, one edition OF which
was slightly imperfect. IL is TO be hoped tina.
at some future day a national Observatory
Dna oo ,fx NH oh he N