Sacramento daily record-union. [volume] (Sacramento [Calif.]) 1875-1891, 1882-12-16
THE TRANSIT OBSERVATIONS AND LON
GITUDEs, RECaTFIED BY A. q.
GODDARD. CE

EcSonCicu SumceDluR es iOuUFss " appears
that we cannot exactly adopt the Signal Ser.
vice loneitudes in another paper For in.
stance, Professor D1vidson's Observatory on
Clay.street bill and Octavia street, where
Captain GiibaTt lin chsrge) took the obserya.
tions, is il longitude 1929. 25m. Ais, as de-
tarmined by Professor Davidson few years
Eince, whereas the Signal Service still call
San Francizco 122d. 26m. 15s., which was
what Lieutenant Tcowbridge made Lime
Point. in San Francisco Bay, in the Coast
Survey of 1858 81. II gave the relative time
from Greenwich 81. 9m. 45s., while Prof
Davidson's Observatory gives it 81. 9m.
A.. 1885,, or about 2ls. difference in time.
But the Signal Services Washington
longitude of I'D. 1m. is much more out
of the way from the Dome Observatory.
1t ia true that it has been vsIiously computed
at different times from I'd. 0n. lbs. to I'D.
Sn., which may be found in Blacks atlas
published in 1871; but Johnson's cyclopedia,
1877, and Lcomis' astronomy give it I'D.
2m. AS. If we take the relative difference,
however, of the late eminent and lamented
DR.. Diapers computation of his observatory
at Hastings, near New York, which in his
transit of Mercury observation, May q, 1875,
he gave as 13d. 52m. 25s., or 23h. Am. 1Ss.
in time, calling Washington 24h. The diff
ference, 12m. 42s.. is equal to Sd. ION. 3es.,
which, added to 73j, SIM. 25s., mskes I'D
2D. 55s. Tnas is doubtless very nearly correct.
But special observations for longitude or
time from Greenwich, after the electric At
lautic cable was laid, were taken by DR..
Gould, Professor HilRsrd and another, which
give mean of 5h. 8n. 12.l2s., convertible
TO I'D. 3In. l.S5 so probably that is most
correct OF all, and IS our starting point
Then il we deduct 5h Sn. 1928 from Pro-
fessor DaVidson's observatary-Sh. On.
~ 733s.-we have 81. In. 80 6l3s. as the
difference between Washington time ard
the Clay-street observatory, or, if we
please, deduct I'D. 3n. 1855, \ ashing-
ton, from 122d. % a. Ais, Cisy.street,
giving Add. 22n. 80 %, these should give
the same results in time, or show that the
Atlantic cable observations vera not con-
nec.ed with the game part Of Washington.
II does give us the same result, or 3h. 1m
3 g.. for difference between Washington and
the Davidson Observatory. Therefore if we
take the given predicted Washington time for
the transit, and deduct the difference, we
shall have the predicted time for Professor
DaVidson's Observatory in San Francisco,
Captain Gilbert's place OF obGervation-pot,
of course, the Csrro Roble, II. NJ, station,
where Professor ID wilson had such edmira-
bic success-except, however, the first con-
tact. which his station seems to have missed,
as the sun was less than dismete above the
Otzau mountains, at tie firsG internal con-
tact as the Bulletin stated. Well, then, the
prediction for Captain Gilbert stood:
Washington. San Francisco
First contact: .......s:55 A. M. 553 56.4A NJ.
First internal contact. .9:l6 A. NJ. Ola 564A.W
Second internal contact..2:Ss P. NJ. 1l:36 SOFA N.
Last contact. ......... 300 P. N. HES 564 A NJ.
But there is an admirable chart in Proc.
tors "The Universe and the Coming Tran.
sits," showing that irereEs is retarded eight
minutes at about 10S' longitu lie, and egress
accelerated three TO four minutes on our
coast, and five minutes at about 104' longitude.
The second internal or third contact was not
due at 1lh. 36n. Sc As, but OF the same
figure we must ascertain. II is not quite
clear, however, that the eight minutes or even
seven and a hall minutes retardation ex-
tends further than the diagonal path shown
running from about Wyoming to the Gulf of
| California, but it undoubtedly indicates i'm
portant differences, which may clear up the Oh
served differences at San Francisco and Sac
rsmento. Captain Gilbert recorded his OBJ
servation OF the second internal contact at
1l:i2 A. NJ. snd the last contact at 12h. Pm,
lO.., showiog 5m. 3.6s retardation at the
| third contact, and 3m. Is 6s. at the Isst con-
tact from the Washington predicted time.
But it appears that the we'll known medical
almanac of Dr. Jayne, Philadelphia. gives
the time for thirty-one cities IN the United
States, including Sacramento and San Fran
cisco, and 1l:42 a. N. is given for San Fran
clsc), and we may note that if we deduct
three minutes acceleIation from eight min
utes' retardation, it leaves the retardstion FIVE
nil utes, or within 6s of the Observance.
or taxing the last contact and Geducting 35m.
scceleration from I'm. retardation, it would
give us S4m. retardstioD, which would be
within SOS. OF the last contact observation at
San Francisco. a very little alteration in
the proportions of the scceleration and re.
taTdatl9n would give the exact results. there
fore. have dwelt upon the San Francisco
observations iecsuse they afford the kew TO
the correctness of Major Bendsr's st the
State Capitol; but now, then, we must as
certain what the longitude of our State Capi.
tol is. Professor Hall kindly informs me
that it is q So miles less or east of 1924, true
| Longitude. At SD. Bonn. Sacramento latitude
that would give US IBID 29n. As, while the
Coast Survey In 1873 ordered In. added to
every degree OF old longitude, showing that
formerly it would have read, after adding The
I'm. IBID, BON. 4s. The Signal Service
nguTe-l2ld. 3lm.-appears to be TOO much.
Adopting I'D. 29m. IA, then, as the longi.
tude of the State Capitol west of Green
wien, the difference from Ssn Francisco ia
ooh. 1865; for adding that to my computa-
ton OF ne dome of the Safe Capitol-12Id.
z9m. Z. 4s.-which has never been given by
any civil engineer before, we have 1921. 25m.
Ais. for Professor Davrison's Observatory ON
Clay-street hill 1t must be recollected that
the Coast Survey Office, Washington square,
San francisco, was called in longitude 1921,
24m. 80 49,, hut no doubt should have been
1928. 25m 80. 49s. Tie sea. 80 6s. gives us 3u.
40 Zis. difference OF time, DR. later than San
Francisco, so that, as we found before, that
the San Francisco. or Captain Gilbers's OBJ
serVaLlon OF llh, Am, came out right with
the proper retardatiUn added, and conformet
to DIR. Jayne's almanac; so IL we add 3m.
40 40 Z4S Lacour difference Of time, to 1lh.
4zm., we have as result 11h. 45m. As pa,
which includes the same retardation "a we
allowed for San Francisco, and this comes
out IL I6s only less than 11h. 46 N. given in
DR.. Jayne's almanac. The observation was
In fact called as explained last week, at llh.
4Zm 49,, San Francisco time adding 81.
46n. 24s. therefore, we have liz. 46n.
81 "a. showing that Major Bender was
probably 81 24s. late, es he was confident he
VAS, and even admitted, 13 76s. more
which would make the actual occurrence nrs.
clsely what estimate it should have been,
llh. 45m. IS 24s. My mode Of getting ths
true retardsHon was only approximate how
ever. The last contact would work out az
follows: Captain Gilbert's was ia. 2m. lOs..
with probable retsrdation of 3m. 1856. in.
cindeo. we have then merely to add the
difference Of our time. 3n. 46 24s. to l2n. 2m.
lOs., making Ia. 5n. 30 24s. The actual
time Mr.. Shearer called to Major Bender
was In. I'm. 25s., by San Francisco time.
adding, therefore. 3m. 46 24s. The Saera.
mento time called was 12h 6n. 11.2Is.,
showing possibility that it was
called fifteen seconds too late to
be in harmony with Captain Gilberts. Thus,
then, We have arrived at conclusions that har
monizs with science and the facts. and prove
the correctness of Captain Gilbert's observa.
tions. Professor Proctor's elaborate descrip.
tions and chart for the transit of December
6. 1882, and the really admirable precise fig-
ures given by DR.. Jsyae's Almanac, for
Which ms astronomer Is deserving of the pub.
lie thanks, whereas the Scientific A rne1,icGn IL
1t quoted from the Nautical Almanac, which
l have rot yet had an opportunity of seeing.
still only gave us the Washington time
without the retardation added, and WAC con-.