The New York herald. [volume] (New York [N.Y.]) 1840-1920, 1875-02-17

fessors Hall and Wheeler were entirely successful
| The image of the was very steady. The vibra-
| ton experienced on cold days was absent, the
haze and warmth conducting TO steady the image.
| The PHOTOGRAPHERS, however, were making bad
| work Of their part Of the programme. They had
| prepared for clear day and arranged TO take
| picture every two minutes. They were, therefore,
In no condition to cope with the exigencies OF the
! situation. With q plain glass lens 1t was found
impossible 10 secure sufficient light to photograph
the contacts. 1t was discovered. when too late
that sivered mirror was essential. Although
Professors Hall and Wheeler could see the sun and
Venus distinctly through their telescopes the pho
tographers failed to obtain single perfect view
OF the contacts or one that could De maze avail
able in any way. 1t was not until Professor
Hall entered the room and made several hasty
changes that the apparatus WIS rendered SER
vlceabie The plates had been prepared Tor
clear day, and having failed at first exposure,
were permitted to remain unused in the instru-
ment. AS q consequence some delay was caused
| IN preparing new plates; but when they were
| done the work progressed without difficulty.
| While Venus was upon the SUMS disk thirteen eX-
| ceilent photographs Shown IN diagram p were
| obtained.
MEASUREMENTS OF CCSPS IMPRACTICABLE.
Professor Hall found 1t impossible to measure
cusps accurately on account or the scarcity OF
| light and as the day progressed and the atmos-
| phere became denser difficulty increased.
Twenty-elght minutes alter the first contact
Professors Hall aud Wheeler made satisfactory
| observations OF the second contact. Then the sky
| became clearer, ana large number OF photo.
graphs, thirteen being (as remarked ahovel
| as perfect as could be wished, were taken.
| At the time OF the third contact the sky grew
| quite hazy and the time was observed with some
| uncertainty. The clouds gathered rapidly, and
| the fourth contact was lost entirely.
| SPECULATION AS THE RESULTS.
| Notwithstanding the bad weather Professor
| Han feels that the results are important and the
| observations success. Much depends upon
| solution OF the problem whether photographs can
| lie measured with the requisite accuracy. When
| 1t IS remembered that the negatives must be
brought many thousands OF miles, through varied
temperatures, TO Washington and here subjected
TO measure ments which must not vary from abso-
| lutte accuracy one ten-thousandth OF an inch,
some idea OF the decacy OF the undertaking can
| be obtained. should the colloiton film Shrink but
in the least degree, the entire work lost. In
tests hitherto made the pictures have failed to
| give satisfactory results. but with the improved
apparatus used on This occasion Professor Hall
Lopes that all defects have been rem.
| cdied and that the Photographs will
| be found accurate. As not less than
| two-thirds of the amount Of money
used by the American expeditions was devoted TO
the Photographic method 1t will he seen that 1t is
very desirable that Professor Has expectations
should be verified. II they are, the advantage to
! be derived by the cause OF science from the dis.
covery is inestlmaDle.
| INGENUITY OF AMERICAN CHEMISTS
The Professor Is satisfied that the American
apparatus for photographing is much superior to
! that used by European expeditions. The
| En- mo Mt fhai tortoi
thus obtaining more light. but what we lose IN
| light Is more than compensated by the exactness
with which we get positions. the forty-foot nori-
| zontal telescope used by the Americans be sci
| with theoretical eXactness. An image OF the
| plumb line is photographed upon each plate. BY
means of this and the distance between the
centres Of the two ob ects, which can be meas
ured, the position OF Venus on the SUMS disk
may be fully determined.
| HAsrY HOME RUN.
Professor Halls party left yadivostock on the
| 18th OF December lest the winter should set in
and render 1t impossible to get the steamer out OF
the harbor. They put to Nagasaki, and there the
| party broke up. Messrs Wheeler and Clarke are
on their journey home BY way Of Europe; Messrs
Rockwell aud Lacey VIII PROBABLY take up their
residence as teachers In japan and Messrs. Gard.
| ner and Tappan come upon the next steamer.
Professor Hall left Yokohama on the 9th OF Janu.
| AIRY, SallnS III INC AItlua, u herman steamer,
chartered TO supply the place OF the Inflated
Japan. Throughout the expedition the party en-
joyed excellent health and received the Kindest
treatment from all with whom they came in
contact
| TIE FOREIGN EXPEDITIONS IN AsIA-EAsTERN AS
| TRoNoMEEs SUCCESSFUL ALONG THE LINE
or the foreign expeditions in the vicinity OF
| vladivostock, Professor Hall brings reports as
| follows:-
| At Vladvostock the Russian party under Lieu
tenant Onazawitcn observed the nrst. second and
| third contacts; took no photographs, but made
excellent measurements OF cusps with flar
| micrometer
The Russian party under DR.. Glasenapp wer.
stationed near Lake Hanka, and obtained partial
observations with heliometer.
AT Port Nabodka, sixty miles northeast OF
vadivOstock, Lieutenant Shubtn was stationed
and he had made no report.
AT Possiett Strive and Hasselberg observed the
| first and second contac,s and took photographs.
The party at Nertschnsk. on the mountains
used heiometed, had fine day and were en-.
| trey successful.
| contacts were Observed
The Dutch party at Chectoo, under DR.. valcn.
timer, made complete helomeric and photo
graphic observations.
At nearly all OF the stations on the coast the
weather was partially cloudy.
EXPLANATION OF THE DIAGRAMS.
The first oil the accompanying engravngs shows
two pictures OF the sun figures and y. Figure