The New York herald., 1877-03-23
The EXPECTED TRANSIT.

DID VULCAN PASS BEFORE APOLLO YEsTER-
DAY?.-TnE WEATHER uNPnoPIrIoUs FOR OBJ
sEnvATIoN.
Until tho arrival Of advces from European observa.
tories It will OF course remain uncertain whether
Lcverers prediction of transit OF Vulcan yesterday
has verified since yesterday aud tho day before
both too cloudy for observations at the various
American observat0ries For al least II verified at
all the observations that will settle unsette
NJ. Leverrier's claims 10 DO regarded as the
wegher Of worlds must be gathered by European tubes
drzzling rain, which set In day before yesterday,
was continued all day yesterday by cloudy weather,
which commenced TO clear only with the departure of
the sun; and thus, disappointed and little ILL natured
withal, American observers will have to commence
their operations tho day after tho evont This
well perhaps, for NJ Leverr,er's calculations very
vague the exact date whom the transit may
be expected aud II Is just iikoy to DO found to-day
as It was yesterday. Private observers in this city,
whom tho reporter OF the HHRALp visited yesterday
afternoon express tho intention OF devotng to-day
q study OF tho suns disk, provided the weather is
favorable to observation.
SOURCES oP RxRoR TO BE AVOIDED.
There two sources Of against which amateur
astronomers should be warned In advance In the first
instance, although spots usually present crenaed
edges surrounded with pcnumbrn. such is invari-
ably tho case, und they occasionally observed
perfectly round spots, lacking the usual shadow FRINGE
melting into luminosity. Such o spot was mistaken
by Weber April for planet in transit and idont-
fed with probability sun spot by Vcntosa Jansen
aud Airy. Tho photograph process Is pretty sure
means OF detecting and exposing tho deceptive
nature of the phenomenon; while, again. tho
suns surface Is composed OF granulatons their
cessvc immersion and cmersion as the body moves
the disk is decisive test Of Its soldy and real
opacity. Another Of Ia inseparabe from
the structure Of the telescope As the cornea Of the
human eye s q surface, II onc'a eye Is placed
q certain distance from the eyepece in examining
q round body the moon, Tor instance. the surace Of
tho cornca reflects upon tho eycpicco glass perfect
image of tho body under examination. In this case
q small but exact image OF tho sun would appear
upon the disk OF that body ana might readily DO
mistaken for "A planet Errors arising IRON this
numerous among astronomers that
tho existence OF moon TO the planet Venus
is still doubtful. although many observers claim TO
Monclnir, N. j., on July 23, at three =. NJ, and al
though it is difficult to imagine that two observers
should have beeu deceived the same manner tho
day, the Same hour OF the dny, particularly
whom oi them was hts guard, ind neglected no
ossIbe that such may have been the case, ana that
tho OF error one that can be obvated only by
taking n photograph. There Is this in favor Of tho
genuineness oi tho two Montclair observations
namely that they both represent the supposed planet
the track It must necessarily follow IN crossing tho
suns disk.
COLLATION. or PREVIOUS OBSERVATIONS.
1t should DO remembered again IN iavor Of con-
tnued observations that the period OF Vulcan Is
settled Leverrier has xed It at threo different cal
cuations, Vt A. rs aud 80 days. and Tee fixes Il on
repeated observations ~ 2302 which Is In accord with
OF recorded data For instance Mayer It
74th day Of tho year 1885, and Tce the 25Sth
day OF 1883 Tho difference betwcon these dates Is
81. OH "a days, which, divided by % o. gives 16l0s
revolutions, With about ten hours TO spare. Mayor
saw II AT tho descending node aud Tice at the
ascending. Again, from the 74th day Of 1858,
when Mayer saw IT, TO tho S5th day OF 1852 when
Lescarbault took his observation OF transit exactly
1908 revolutions Of 23 O2 days each Intervene with
few hours only to spare and Weber Is correct, from
l75S IA days. 1876 VI days (Aprl there
doducting the time II would take the panct to move
from It's inferior conjunction, 1873 revolutions OF
1902 with about II hours to spare. Again. from 1852
IS days, when Lescarbaut observed tho transit,
1853. 25S days, when rIcc observed It, are exactly
~ revolutions, with Z hours to spare. The one
the ascending node and the other at tho
descending Tho observations taken In October, 1907,
are IN perfect coincidence with "a period Of between
% and ~ days wnen compared with those taken IN
October 1885, and with the series described yesterday
but they ure out OF tune with the previous by
Just half revolution H. 81 days, that to render
them ali harmonious It must be supposed that tnerc
two intramercuria planets each having the same
period and revolving In the same orbit. The problem
is lind what causes the pcrtur baton of Mercury,
ana somo New Yorker may be lucky enough to solve
II In tnding Vulcan.