New-York tribune. [volume] (New York [N.Y.]) 1866-1924, 1875-03-26

Mr. Wheeler placed the theodoIte our neliostat pier
haTbor with our station From his calculations the
highest hin back OF the town is $40 feet above sea eVe
Tue observations made In the triangulaton WIZ DO
found In blank book No This book also contains the
determinations OF the divisions OF the various levels OF
the mcrOmeter aud wire Intervals OF the transit
instrument OF quality OF the pivots &c Tue OD
servaOns Tor latitude were begun Octn Inc aIltuuo
was determined by the American method OF measuti,s
zenith distances OF stars long and so skifuIy sp
Piled by the u s. Coast Survey The value Of the screw
VI the micrometer was found Oy two me,hoIs, tno
transit placed on one OF the cOlnaoa
piers in Washington, and the Intervals uetweon hv
Inrce wires moved by the screw were uleanuIeu W
means Of the meridian circle. Tni: method gave
A. ya,d,vos,ol P5iaTls was observed at Its eastern
eongation by Mr. Wheeler and myself and the results OF
the observations are as follows: oo
October 4. revolution
October 3, one revolution. .'..'''.'''''''''.OaooV
Ns,n......:...;.........,....,......,....oS53s%5
Correction for refrIctiOn ........'.......... OiO'
The yano adopted was 6s.7OV. The destinations Of the
stars used for latitude taken from the catalogue
prepared by Prot. T. H. Stafford for the United States
Lake Survey, under direction OF Gen. COmStock. The
latitude Of our transit pier Resulting from the preUl.
nary reduction, made by Mr. Wheeler, Of IL pans OF
star, Is o.o,o,-,
There observations aud reductions Will no 1Ouhu I'D
the bank books for latitude. msguIiylDg power oi
~ used with the transit Instrument.
PHOTOGRAPHIC OBSERVATIONS.
The lnal adjustments OF the Photographic apparatus
we're made by Messrs. Wheeler and Clarke during the
anew IN the ginuinS OF November with the intention
OF beginning regular practice Nov. s. Bad weather
prevented work for several days. and aftervard we
Experienced difficulties with the apparatus The
they woulI not in COLI weather. They were care
fully cleaned 10y Mr.. rdner OIL was applies except
tDeY performed tUierLoly well. A circle was described
the outside OF the block metallic shutter OF Tue SHE
the Photographic hOuse anu BY means OF this circle
once Win the Inst directions received flon the commits
Ngn had iPi
shaped plate with white CLOTH t5r TINS was done inc
9p0osrsOng iba weig The local dancs had been
erIOneou3lY measured, Tne cohi1-shaped plate wns
with that found by experiment with ground glass, but
the photographs were no better After some delay II
was fOunl that the trouble came chiefly from light re-
cted from the white cloth and other surfaces, TO the
sensitive plate. Tie cloth was removed and tho sur
faces pin,eI dead black color with lamp black aud
water There stil remained source OF trouble which
uipOssib3 10 avoid. This was the difference OF
Temperatures inside aud outside of tho photographs
house, which varied from 20 70 50 degrees. TIis
Itself with what seems to me the weakest part IN
commission Tor doing the Photographic WORK that j.
with fact that tue glass mirror reh cts bur small
per centage Of the light. Tho reflection OF 50 small
quantity Of hight through the PHOTOGRAPHIC lens made 1t
necessary TO open the slit IN the Slide to its
E aS s, %iSsn 70 move move the sGo b. hand
slowly past the plate and thus lenSthen the time Of ex
pOsure. But II the time OF exposure was much length
graphs blurred ana iGdtnyt around the edge OF the
sun. Ii was decided to make iAint ana sharp photO
graphs Rather than those win blurred gcs ana IA
dense \ tOgrdp gcr5 Eid been Instructed 10
make. Tic plumb lIe gave some r0uDle from It's IaD-
10y be caught and he'd fast ~ ta drppDS5 OF the
plate. GA the morning OF the day Ot tranl the appa-
rdtus was ~ good aiuSIuenI ana MT CIaSe ana ms a.
sisants mai everyIAng In readiness Tor inakl- 2Oj
Photographs. Al the time OF tho hgSi and second con
facts Tue naz, prevented taem IRON making any pAOIG
graphs although the teo5 npes gave Us faint out very
ne images OF the sun ana Neans' Alter V5nlS nau en-
icred Wholly on he suns DISK the maze became thinner,
ant few photographs were Made, wHeu We were
stopped ~ denser nazs Aooat an hour ater TINS an
0tler set OF photOS apns IS MADE ana SUI later ana
near the end OF the transit nlue Photographic were
made. There are thinh, 10 p.o.oSIdoAs tAat wa hl-
nit OF measurement the OtAers VIII Dc found PROBABLY
too FAINT to DC used.
Tn. iron piers were very steady in position and the
measurements from the surface OF the Photographic
lens to that Of the ruled plate only indicate changes
that explained Uy change OF temperature OF the
Ineasuriugrod. The notes In ume-booL No give the
data for determining the aznItn OF the Iuied plate.
NOOK TIE level Of tue pate-oller was broken on the
Journey and the TUBE Of the ensneer level was used IN
III zoe Oft Tue pumolino was accidentally broken by
Mr. Rock we'll aOOdt an hour before the time OF the first
contact Jf Venus, ana whe1 we were measuring the
focal distance A we were obliged TO inselt now
pumb line the measurement was made hurrieily, ana
We had time TO prepare for observing the first
contact Tne records ptrauinG TO the photographs the
OF the distance, a., viii be found in
the Photographic book.
TIE EQUATORIAL.
This instrument is No. $50 Avian Clark & Sons. The
cap however, belongs No $780, and the adaper for the
eve pieces to some telescope the changes having
been made probably in Washington. this instrument
being the last one packed The objective has aper
ture of five inches Tho instrument very convenient
one for use hat the position or the pendulum for the
driving clock such as reuder IL liable TO he hit in
reversing the telescope. The pendulum received blow
some time about Nov. "a, but put in good order
again by Mr. Glrdn"r and the driving clock performed
well Tue doube-lmage micrOmcter mas two powers
neither Of which gives images Tat are quite OF equal
brghtness but the higher power Is the better one
f. y attempts made 10 observe OccnltttiOns
of stars, but the observations were given up
on account OF the equatorial building and be-
cause Lieut.. Onazawitcn. the Russian astronomer at
WladvOstoK was engaged In t1e same wofk. PrelIm-
mary observations made for determining the CO.
Incidence OF images aud the zero Of the position circle
Tle observations Of the times OF the first and second
contacts of Venus with the suns limb, made with the
1yeiuch equatorial, Will he found page OF equa-
Orll booa, AM remarks on pages and 10. These OD
serydtiJns were made Nv myself and the times were
noted bv Mr. Gardlpr and Lieut.. VI jr0ng OF the K3ar
sarge failed TO get the third contact and could not
venture 10 ren0ye tue cOOred shade aud tie Being
low the haze was so dense az TO maze tina limb too
faint for observing with the shade Mr.. Wheeler OBJ
served with au Avian Clark til scope OF three inches
aperture which lent TO Oy Prof. Coffin, super
Ltendent OF The NauiicuI Almanac office. Mr. Wlcelers
will found between pages IL and 10 OF tho equatorial
books The positions OF the eqCGtorias with Respect 10
the pier Of TIC transit WIS as follows: The tge-inch
eqnal Osll 81 feet west and the three-inCh
t0ria 20 feet OF this per The approximate times
Of contacts are
First contle...l0 80 4a7 wlGivosok Hall. observer
Frs .ta..lO ~ 90 VIA yOhOk IA wheeler Observer