Full resolution (JPEG) - On this page / på denna sida - Sidor ...
<< prev. page << föreg. sida << >> nästa sida >> next page >>
Below is the raw OCR text
from the above scanned image.
Do you see an error? Proofread the page now!
Här nedan syns maskintolkade texten från faksimilbilden ovan.
Ser du något fel? Korrekturläs sidan nu!
This page has never been proofread. / Denna sida har aldrig korrekturlästs.
51
Kronometrene stod i et Skab i Arbejdssalonen om
Bagbord (Fig, 4, c). De blev optrukne hver Morgen og
derpaa indbyrdes sammenlignede.
I 1876 havdes 3 Kronometre ombord, et af Kuliberg,
et af Mewes og et af Frodsham. Det første, der ved den
paa Bergens Observatorium af Hr. Astrand foretagne
Undersøgelse før Rejsen viste den jevneste Gang, blev benyttet
som Iloveduhr.
1 1877 og 1878 havdes 4 Kronometre ombord, nemlig
foruden de 3 nævte. et af Reid, der var Skibet tilhørende.
Dette Kronometer viste en saa fortræffelig jevn Gang, at
det benyttedes som Hoveduhr de 2 sidste Aar.
Kronometrenes Stand blev bestemt, først paa Bergens
Observatorium (undtagen Reid) og senere hovedsagelig ved
de telegrafiske Tidssignaler trå Christiania. Disse Signaler
gives fra Observatoriet i Christiania hver Onsdag Morgen
Kl. 8 Formiddag og hver Søndag Morgen Kl. 9 Form.,
Greenwich Middeltid, til samtlige norske Telegrafstationer.
Signalerne gives paa Observatoriet direkte etter
Normalpendelen. Der telegraferes liver Gang 3 Signaler, hvert
bestaaende af et enkelt Slag fra Nøglen paa Morses
Telegrafapparat, nemlig 7’< 59m 0S, 8’’ 0m 0 S og 8A lm 0S om
Onsdagen og 8’’ 59m O4, 9* Om 0S og 9A l’" O’ om
Søndagen. For at skille mellem Signalerne betegnes de
henholdsvis med 1, 2 og 3 dobbelte Slag strax efter Signalet.
Faa Modtagelsesstationen, hvor man indfinder sig ined sit
Kronometer eller Observationsuhr, høres Signalerne kort og
skarpt paa Morses Apparat.
Ved 15 Par korresponderende Solhøjder paa Husø
(4" 36’ 57" øst f. Greenwich) fandt Prof. Mohn den 10de
Juni 1876 Kronometret Kuliberg 0 ’’ 38 m 43.3 " foran
Greenwich Middeltid.
Under Expeditionens Ophold i Reykjavik toges af
Lieutn. Petersen og mig den 1ste August 1876 14 Par
korresponderende Solhøjder paa en Plads, der ligger omtrent
200 Alen østenfor Kirken. Ifølge velvillig Meddelelse fra
Chefen for det Kgl. Danske Søkaart-Archiv, Hr.
Kommandør Rothe, er, ifølge saavel ældre som nyere Iagttagelser,
Længden af et Punkt, der ligger 600 Alen vestenfor Kirken
210 54’ 46" W. Greenwich.
Vor Observationsplads ligger saaledes ca. 800 Alen
øst for dette Punkt, hvilket, da Bredden er 64 ° 9’, svarer,
til 38" i Længde, og Længden af vor Observationsplads
bliver saaledes 21° 54’ 8" W. Greenwich eller i Tid:
1Ä 27’" 36/5
Kronometrets Stand for Stedets
Middeltid fandtes 2’’ 6m 55/7 foran
frequently observed the sun at midnight. The days on which
no observations could be taken were very few indeed.
The Chronometers we kept in a cupboard in the
workroom, on the port side (Fig. 4, c). They were wound up
every morning, and duly compared.
On the first cruise, in 1876, we had 3 chronometers, —
one by Kullberg, one by Mewes, and one by Frodsham
That by Kullberg, which, previous to the departure of the
Expedition, Mr. Astrand, Director of the Bergen Observatory,
had found to have the most uniform rate of the three, w:v
our principal timekeeper in 1876.
In 1877 and 1878 there was a fourth chronometer,
one of Reicl’s, belonging to the ship. This instrument
having a remarkably uniform rate, we made it our chief
timekeeper on the two last cruises.
The error of each chronometer was first determined
at the Bergen Observatory (saving that of the Reid), and
afterwards chiefly by comparison with the time-signals
telegraphed from Christiania. The observatory of that city
transmits these signals every Wednesday morning at 8 a. ra. and
every Sunday morning at 9 a. m., Greenwich mean time,
to all Norwegian telegraph-stations. The time is taken at
the observatory direct from the standard-clock. Three
separate time-signals, each consisting of a single click, are
telegraphed, from the key of Morse’s apparatus, at intervals
of one minute, viz.: — Wednesdays, at 7’’ 59m 0s, 8A 0m
O’, and 8’’ l’" O’; Sundays, at 8’’ 59m 0s, 9’’ 0™ 0s, and
9’’ 1 "’ 0 s. To distinguish between the signals, they are
respectively indicated by double clicks, 1, 2, and 3, following
after the signal in the order of succession. At the receiving
station, where the observer stands by with his chronometer
or hack-watch in hand, the signals come sharp and distinct
from Morse’s apparatus.
From 15 pairs ot equal solar altitudes, taken at Husø
(long. 4° 36’ 57" E.) on the 10th of June 1876, Professor
Mohn found the error of Kullbergs chronometer, on
Greenwich mean time, to be O’’ 38m 43/3 fast.
During the stay of the Expedition at Reykjavik,
Lieutenant Petersen and myself took 14 pairs of equal
solar altitudes, at a point about 140 yards east of the
cathedral. From information kindly furnished by
Commodore Rothe, Hydrographer to the Royal Danish Navy, it
appears that the longitude of a point 410 yards west of the
church, has been found, by earlier as well as recent
observations, to be —
21° 54’ 46" W.
Our post of observation was thus about 550 yards
east of this point, which corresponds, the latitude being
64 ° 9’, to 38" in longitude. Hence, our post of observation
was in
Longitude 21 0 54’ 8" W., or in time 1’’ 27m 36/5
Error of chronometer on mean time of
place 2’’ 6m 55/7 last;
altsaa dets Stand for Greenwich
Middeltid O’’ 39’" 19/2 foran
therefore on Greenwich mean time O’’39™ 19/2 fast.
<< prev. page << föreg. sida << >> nästa sida >> next page >>
