New-York tribune. [volume] (New York [N.Y.]) 1866-1924, 1875-04-03
VENUS DURING TRANSIT.
LAST OF THE OFFICIAL REPORTS OF oBsERv-
Frs

LAoI Of IHE OftICAL hEfOhlo VI ODor1h'-
Frs.
THE TRANSIT AT HOBART TOWN, TAsMANh-RE-
PORT OF PRoF.-wM HARDNESS. U. s. N.-A LONG
PERIOD OF CLOUDY wEATHER-M0RE THAN lOo
PHOTOGRAPHS OF THE TRANSIT OBTAINED.
HOBART Tows, TASMANIA, Feb. g. 1870.
Rear Adnirai c. H. DAVIS President Transit Of Venus
Commission Washington, d. c.
SIR: Before now Mr. Waldo will doubtless
have handed the copy OF our records and the pno
tographs OF the transit Of Venus, which urusted 10
bis care. He will also have told you how our ehorts
igreat extent frustrated by the bad weather
which experienced but, as our detailed journal Is
not yet ready for transmission TO the COMMISSION IL
will perhaps be well for to give you short account
Of operations
The transfs instrument was mounted on Oct. II. but
owing 10 cloudy weather observations could be %
tanned till the evening OF Oct II. The mounting OF the
equatorial finished Oct Il. Tine tstexpermental
picture taken with the Photographic apparatus at
1235 D. NJ Oct. % but clouds prevented second pic.
ture being obtaued that day. BY Oct 20 the focus OF
the Photographic objective had been determined Win
considerable degree accuracy and the evening Of
that day all the adjustments made approximately
BY Oct 80 the roof over the Photographic telescope
was finished and the iron measuring rod was mounted
Experiments with the apparatus were then continued
till Nov. H. when all the adjustments, except the azI-
and the heliOstat axis. considered 10 De as
perfect as possible, and the plumb line wds suspended
on the afternoon OF Nov II / placed the party in
charge OF Mr. Waldo, and went To Melbourne in order
to make arrangements with Mr. Elery Tor determining
Geographically the difference longitude between my
station ana his Observatory As permission to the
cable between Australia and Tasmania had 10 De OD-
tanned from London, time was spent In the Rego-
tiatious but finally everything satisfactorily ar
ranged, and returned TO Hobart Town. arriving there
on the afternoon OF Nov. %. The tasmania Govern
carried OF their wires into my transit
house, aud IL was expected that the longitude WORK
could completed before day OF the transit. In
this however we were disappointed The instruments
rst provided for sesding clock signals through the
cable could not be made TO work on account OF the caoe
induction, and new instruments, which were not nm
ished till after the transit, had 20 be constructed IN
their place In reality this made little dnerenee TOT,
during the whole OF that period the sky at Hobart Town
cloudy that no tine observations could be made
kept no regular journal OF the weather. put OBSERVE
tions made with the transit Instrument whenever
the state OF tue sky permitted and an inspection OF inc
records will show how seldom that was On most Oh
the nights, when did observe, we were much an
noyed By clouds, aud generally by midnight the heay,
' doSs ~ resrnse 70 the sSde oSsefyaons It
may he remarked that l employed only the New Cape
OF Good Hope and Melbourne catalogues aud conse-
Gueutly tie stars composing my p.irs were sometimes
50 far apart That they involved good zeal OF waiting
SIN IL was found practcaDe % get un3 rtars oetWeen
the star for latitude My expectation waste nave
gOt pairs OF observations Tor latitude by the END OF
October and after that to have observed for time only
but in this was disappointed. In the records OF the
time observations the azimuth stars are sometimes des-
ignated by a number instead OF " namt. IN such
cases numbers refer TO the st OF southern clrcum-
polar stars furnished by The Melbourne Oo5erylory,
and printed Ia number l.4G Oh the AS"0"o"'ScAe
Between the date OF my return from Melbourne ana
the day OF transit there not single clear nlGht
gu Nov. % 1t cleared up at sunset ana went 10 tue
station expecting 10 make nigut OF IL. Degan win
latitude stars because my WOtkIhs st Oh ITEM ran ouS
early In the evening, but AFTER geing only two pairs
the sky became overcast and nothing more could be
done Nor the days any better than the nighIs.
On Nov 20 | nnisLed my apparatus TOR taking the
small pictures during the interval "eeD the hrst and
secoDd contacts ani Hghn 9et%eeA ile tnlIu aua
fourth contacts; aud although | WATCHED anXlously
for CLEAN OF sunshine TO test 1t. tho OpDOrtu-
nifty never came ana the nrst pictures taken Wltn
IL were those GU the day or the transit.
IL will oe observed that IN the records which sent
home there determinations OF the level or the
axis the PHOTOGRAPHIC telescope, nor OF tue distance
between the objective and the sensitive plate prior to
Dec. TIC reason lOf thls r. lnat wien vent 10 et
bourne did consider tine azmuth a. hnaiy adjust
ed, ami lt did not seem worm whle 10 make any
records OF level dis lance until that was uOue Nhen
returned To HOBART Town walled IN vain Tor an OPP
porunIty TO perfect the azmuhi nor could get any
pictures " the sun CONSEQUENTLY Tue apparatus was
not used for anything whatever Uut dummy Practice
aud special attention was pau 10 II III she afternoon
and evening OF Dec - %heh uetettuueu tne eFet VI
the axis measured the distance between the objective
and pate, ana tested anu round correct al the
other Adjustments, except the aZinIih.
on the morning Of Dee the heavens were black and
lowering. ABOUT a. III sHerc wac a neaNy snO%sI oat
by = there were signs OF better weather wnch now
aver proyea deuslge. At 10 O'CLOCK, although the SKY
was bopressy overcast, the whole party was at tho
station and ready work Al l:i0 a. H. the predicted
OF nrst contact not Trace OK t!e sua was visible;
meuts sufficiently Venus hall way on 20 his face
an attempt made TO photograph IT, but without sue
cess Tuen the was again vailed III 12:2O D. ~,
when II Was seen for instant with the planet fully
upon its disk. After that there was heavy rain Tor
nearly an hour and dense clouds VII 81 when suddenly
IN beean To break away Soon rlft Ormed about the
am and at %. 3Tm 20s. p. M the first picture was
fak
ef II remained IN the neghDorhO0d OF the sun TIL
an lam, D. H. and during that time a. pictures were
Ken Of which excellent, ana only TWO were
Doed by the clouds For the remainder u the transit
there were only mOmentary flashes or sunsne but by
utilizing every of tuem between 3n ~ IL. AS aud
an 63lI. "a. p. M "a small pictures obtained.
During the transit party we're assisted by DIR.
E,gard Kershncr Lieut.. Geo. f. Mnkln- ana Assistant
Engineer Ii. y. Stevenson, al OF the L D steamer
svvsrora and also by Major c. j. Mcmahon OF the
English ROYAL Artillery VINO Is an expert amateur pho
tOprapher without KIND cooperation OF these
urmeu II would not have been pOeslD { TO secur 90
many mixtures In short time. halr an hour before
the third contact went TO the equatorial house for the
purpose OF making mcrometrlcaI measures but al JlA
o. NJ. lust as / was about % commence, large cl0Ad
came up and MD the sun. 1t ma NOT pass over TIL
an ann 3Os nearly i've minutes before the pre-
dicted time OF third contact but the thread or light
between Venus aud the suns limb seemed TO me SO
narrow that II there any truth In the Eradication
theory OF the black drop, might break az Instant.
Under these circumstances dared not begin making
mcrometrca measures. Tor lear VI losing Ine cOntact
Al an 35m (nearlyD The sun again Obscured, aud
when the cloud passed that the thread Of light
between Venus and suns limb was just broken, the
cu IN. beinR very sharp aad well defined. AT that
stanf the time was son. 6s by the cbrunOmettr; buud
A. son No 2sg 1 give this observation for what 10 Is
worth but | cannot say how accurate IL Is, because
did not actually the thread Of hight break After
the transit The chrOuOmeter was compared with the
clock as follows: -.
Clock Howard 62j. Bond son 2sS
lhI1ereaLl NaleAA inel
81 n n s 20 sos
AZ ~ 81 $50
az .. 50 800
At that time the correction to Howard, 625. ap-
prOxmately Oh. San. POS. Hence gu JONI o. Dy Bona
& SOU $50 Corresponds approximately 10 5n 3sni Is or
local mean time tile contact and the contact seems
10 have occurred earlier than was predicted As soon
as this observation recorded, turned the double