New-York tribune., 1875-01-30

to make mcrometrtc 0DservatlOns. Mr. littmhh h"o
smaller equatorial for observing contacts Capt Yam
aea used for the Same purpose small field glass Mr.
Edwards had charge Of the helostat and the chrome
graph. The rest were in the Photographic room. One
minute before the predicted time the taking OF photo
graphs began Rapid pictures were taken at intervals
OF about half second until the moment OF contact had
passed Then they ware kept up at regular intervals
until increased cloudiness made II useless Over 100
plates were exposed but many on account OF clouds,
the images were gushabe. 1t believed that
about sixty Of the plates will be found available for
measurement II the sky had remained clear 1t would
have been easy have secured from 200 to 800 pictures
Each of the plates recorded It's instant Of exposure upon
the chronograph. Each Is numbered so that IL may be
identified, when sent to Washington for measurement
The work in the Photographic room was lively. The
plates were albuminized the day previous Six baths
in TO make the plates sensitive As fast as one
plate withdrawn another was added. And as fast
ss the plates taken from the camera they were
passed into the hands of the developers When all was
they vanished and put In their boxes ior
transmission to Washington.
WORK DONE BY THE ASTRONOMERS.
But while the work was in progress In the photograph
room, the astronomers were not idle 1t is well known
that the determination OF first contact is very difficult
The point of ngress is Of course part OF the very prob
lem to be solved and cannot be known with absolute
ing at the exact point is difficult to detect the first
appearance Of the dark body. Prof Davdsons obser-
yaons OF preceded that OF MT Tttman by about ten
seconds And s noticeable that the time both for the
first exterior and interior contact was later taan the
predicted American time by one and half minutes,
and later than the English predicted time ny threo
minutes The interior contact was well observed FOR
tunately the pretty free from the lower s'ra
tum Of clouds, although it was covered by a Nun OF
0hnut
man we're almost simultaneous In their recoru,
and even Yanage with his inferior instrument followed
close upon the Others No phenomenon corresponding "
the gament described by previous observers was oon
here And as the French astronomers mere report nSo
that they saw ligament, 10 seems 10 Do clea '' "
absence on this was connected WIN to slH'o
~ the atmosphere Perhaps tho curtain OF thin cirrus
clouds which covered the sun may have so protected
the lower stratum of the atmosphere that 1t was moro
a,eadv than in clear sunshine At any rate 1t Is now
ouestion whether the theory OF rradaton which has
served as an explanation OF the lgament seen by Tor
mer observers is any longer tenable The last interior
contact also obtained by the observers put OWING
10 Clouds not SO satisfactorily The exterior contact
was concealed behind dense cloud But the most ln-
portaIt part OF Prof Davdsons work was his mcrome
trio measurements during the first stage Of tho transit
With unrivaeu CELEBRITY, and with skill gained ny ~
years experience as oberver, he proceeded to
measure the cusps OF Venus as she passed
upon the disk OF the sun. Bach observation
was recorded with It's time. Tho series oy
working backward will TO determine the instant
Of contact After the planet had entered upon the sun
he set work to measure the distance between tue
edges OF the two bodies. When this had become too
great TO be useful he proceeded to take series OF
measures of the planets diameter and it may safely
be asserted that no measures of the diameter OF Venus
as n luminous body will compare in vaue with those
taken when sho ia projected as sharp dark body
against tho suns disk.
When the came to the meridian series OF Oh
seryations with the transit instrument were made upon
the time Of the passage OF tho first and second limos OF
both the and planet The whole work OF the party
may therefore, be summed up follows: First contact
observed by Davidson and Tittman; second contact
observed well by Davidson and TItman; third contact
observed by Davidson and Tittman; 100 miorometrle
and meridian measurements taken; co available photo
graphs taken. In addition 10 this. series OF mag
netic observations carried through during the
week previous. For the determination OF longi-
tude. Eagasah had been connected with
yadiwostock by the teegraphc method. by series Of
observations in concert with Prot Hall This work was
completed in November VlaTiwostock is connected by
telegraph with ST. Petersburg. and hence this station
is thus connected with the European and American OBJ
servatories In addition TO this Prof Davidson has dis
patched Messrs. Tttman and Edwards to Yedo. who In
connection with himself at Nagasak will observe for
difference Of longitude Thus the capital OF Japan VIII
be linked TO the Western capitals and its longitude pre-
cisey settled And at some subsequent time not far
distant when cable is laid from San Francisco
to Japan, the last link will be put n and one con-
tnuous chain Of longitude determinations will encrcle
the world.
OBSERVATIONS At OTHER STATIONS
1t only remains to state briefly the results Of the OBJ
servatons made at other stations and by other parties
far French
party here had Of course about the opportunities
for obse rvaon the American Prof Jansen detected
the planet with his spectroscope against the coronal
atmosphere before it reached the limb OF tho sun but
he did not succeed in determining by 1t the moment Of
contact This is most important and interesting fact
in physical astronomy although 1t does not aid in the
transit Of Venus problem The first, second and third
contacts observed by the successfully Jansen
observed the moment of geometrca contact and Tasse
rand the moment OF breaking Of light and, although
igament was observed the two observations differ by
more than half minute. Photographs and daguerreo-
types successfully taken during the early part OF
the transit. Two members OF this party had been
dispatched Kobe and there had better weather than
here They observed all the contacts but the last.
At Yedo and Yokohama the day was beautiful. A
Mexican party under the sklul lead OF Senior COvOr-
rubias were situated at Yokohama and we hear were
entirely successful Baron v. Struye, the Russian
Charge dAf3lres who inherlt9 with MS name taste
and skill in astronomy, had also provided himself with
instruments, and Of course was successful.
At yladiwostock the day very bad. and the OBJ.
servations fear almost complete failure. by
cable we hear that 10 photographs only taken.
From Pekng where Prof Watsons party are located,
as well rs French and Russian parties has yet
been received. Strong hopes are felt that they
successful Particular interest is expressed In the
suit of Prof. Young's spectroscopc observations. A
German party at Chefoo believed to have succeeded
1t may be amiss while this subject is fresh tho
minds OF the American people, to state OF the
cusons which have been arrived at from the experience
OF this transit in regard 10 the proper outfit for the
next transit eight years hence The first Is that larger