10.1515/astro-2017-0295
Baltic Astronomy, vol. 20, 297–300, 2011
SOME RELATIONS BETWEEN THE STOCKHOLM AND TARTU
OBSERVATORIES DURING THE 19TH CENTURY
Michael Lindberg
The Royal Swedish Academy of Sciences, Box 50005, SE-104 05 Stockholm,
Sweden; [email protected]
Received: 2011 May 17; accepted: 2011 August 20
Abstract. This article introduces the Royal Swedish Academy of Sciences
and the old Stockholm Observatory. It focuses on the Swedish astronomers Jöns
Svanberg and Nils H. Selander, and on their work with the Struve Geodetic Arc.
The particular relations to the Tartu Observatory through Oskar Backlund and
the contemporary Swedish astronomers in Stockholm are traced.
Key words: history of astronomy
1. THE ROYAL ACADEMY OF SCIENCES AND THE OLD OBSERVATORY
The Stockholm observatory was the first own building the Academy had, and
it provided some very needed space for the growing library and natural history
collections the Academy possessed. The building was designed by architect Carl
Hårleman and was finished in 1753 when the permanent secretary of the Academy
Per Wargentin moved into the apartments in the middle storey. In 1753 he started
his work to determine the position of the observatory, and with observing the
Jovian moons. Initially the instrumentation included a fairly modest collection
of some telescopes, a quadrant, a transit instrument, some pendulum clocks and
other various science instruments. The observatory was fully equipped during the
summer of 1758 when the great quadrant by J. Bird arrived from London and
quickly became the most important instrument at the observatory.
2. JÖNS SVANBERG, NILS SELANDER AND THE STRUVE
GEODETIC ARC
The result of Maupertuis’ Lapland expedition 1736–1737 did verify that Earth
was an oblate spheroid, however his result deviated substantially from contemporary results. Because of this, the Academy proposed another expedition for further
investigation almost 70 years later, this time led by Svanberg and by chief engineer at the Bureau of Surveys Jonas Öfverbom. Their result from the expedition
1802–1803 showed that Earth was not as flattened as Maupertuis purposed. Some
of the instrumentation used during Svanberg’s expedition is still in the collections
of the Academy.
The need to maximise the accuracy was very significant and Struve’s work
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298
Fig. 1. The observatory building in
Stockholm at south with the dome at top.
Image: Michael Lindberg.
M. Lindberg
Fig. 2. The great quadrant by John Bird
from 1757. Image: Michael Lindberg.
Fig. 3. The new meridian room in the west wing. Transit telescope by Reichenbach and
Ertel from 1824 to the left and the transit circle by Ertel from 1830 to the right. Image:
Michael Lindberg.
from 1816–1855 provided an amazingly accurate result on both the size and the
shape of the globe. During 1844 Struve was visiting Sweden and he contacted the
Academy and the initial idea was to incorporate the result from the Selander and
Öfverbom expedition. However, the director of the Royal Swedish Observatory Nils
H. Selander suggested in a report that it would be best to complete Struve’s arc
over the longest possible distance. Consequently, Selander was put in charge of the
Swedish part of the measurement during the third phase from 1844 to 1851. There
were 24 stations in Sweden measured from near Torneå and completed at StuorOivi, most of them were measured by Selander and another Swedish astronomer
Daniel Georg Lindhagen. At that time Lindhagen was working at the Pulkovo
observatory where Struve had become the director.
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Relations between Stockholm and Tartu observatories
299
Fig. 4. Jöns Svanberg 1771–1851. Image: Fig. 5. Nils Haquin Selander 1804–1870.
Centre for History of Science – The Royal Image: Centre for History of Science – The
Royal Swedish Academy of Sciences.
Swedish Academy of Sciences.
Fig. 6. Repetition circle by Etienne LeFig. 7. Oscar Backlund 1846–1916. Imnior from 1801. The instrument was used age: Virtual Museum of the Tartu obserby Jöns Svanberg’s expedition to Lapland vatory.
in 1802–1803. Image: Michael Lindberg.
Also notable is that Selander was one of the four persons who signed Struve’s
final report Arc du Méridien.
3. OSKAR BACKLUND AND THE CONTEMPORARY SWEDISH
RELATIONS TO THE TARTU OBSERVATORY
The Swedish astronomer Backlund worked at Tartu Observatory between 1876
and 1879 before he migrated to the Pulkovo observatory, where he became director
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300
M. Lindberg
Fig. 8. Tartu Tähetorn. Image: Michael Lindberg.
in 1895 for the remainder of his life. His field was concentrated to celestial mechanics, especially orbit calculations on the comet Encke which included perturbations
from surrounding planets. One of Backlund’s closest friends Hjalmar Branting,
was at young age working as an astronomer at the Stockholm Observatory, but
in 1884 he left his position for a career in politics. In 1920 he eventually became
prime minister in Sweden. During an educational trip in Europe 1877, Branting
also visited his friend Backlund in Tartu.
The work done by Swedish astronomers in Tartu should clearly be investigated
and documented in order to preserve the history of the Royal Academy of Sciences
and the Swedish relations to the Tartu Observatory. This can be done by a study
of the source material available both in Sweden and at the Tartu Observatory.
ACKNOWLEDGMENTS.
The author is thankful to The Royal Swedish
Academy of Sciences for financial support.
REFERENCES
Bergström C., Elmqvist Söderlund I. et al. 2003, Huset närmast himlen, Stockholms observatorium 250 år, Stockholm
Jansson B. 1999, Med sikte mot stjärnorna, Dagens Nyheter, 7th February, 1999
Jansson B. 1999, Den unge Branting ville till Observatoriet, Dagens Nyheter, 4th
March, 1999
Pipping G. 1991, The Chamber of Physics, Stockholm
Smith J. R 2005, The Struve Geodetic Arc, Hampshire
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