Skip to main content

Leiden University archives, Observatory, General Management

Identifier: ubl157

Scope and Contents

The archive consists of the correspondence with the Board of Trustees of Leiden University (1837-1945), papers regarding the instruments and the real estate and manuscripts and notes from various staff members, including extensive research notes by J. Woltjer and M. Schmidt.


  • Creation: c. 1829-1992
  • Creation: Bulk c. 1837-1945


Language of Materials

Dutch, some English, German, French

Conditions Governing Use

Since the archive is digitized, the original papers are not free for public access, unless with permission of the curator after a written request with motivation. Other regulations that apply during the use of these materials can be found on the website of Leiden University Library.

Biographical / Historical

The Observatory of Leiden University was founded in 1633, but it was Frederik Kaiser (1808-1872) who laid the foundations for the institute in its modern incarnation. He came to Leiden in the 1820s, and in 1860 founded the new Observatory next to the botanical gardens in Leiden.

Kaiser’s main research program was fundamental astrometry (precision measurement of star positions), using a meridian circle. He had few students. His successor Hendrikus van de Sande Bakhuyzen continued his work. Both Kaiser and Bakhuyzen were also active in geodesy (measuring the earth). Bakhuyzen was succeeded by his younger brother Ernst. By that time, the Observatory was in decline.

In 1918, Willem de Sitter succeeded the younger Bakhuyzen as director of the Observatory. He had already been professor of astronomy since 1908. Together with professor and deputy professor Ejnar Hertzsprung, he started a reorganisation, expanding the institute and introducing new research and education programmes. In 1924 they contracted young Jan Oort. Over the following decades, the Observatory became a prominent astronomical institute with a renowned education programme.

After the Second World War, the Observatory expanded further. Especially radio astronomy became an important subject. In 1974, the institute moved to a new location elsewhere in Leiden.


193 items (2.7 metre)

Abstract in Dutch

Het bestuurlijke archief van de Sterrewacht, met correspondentie tussen de Sterrewacht en het College van Curatoren van de Universiteit Leiden 1837-1945, en stukken betreffende de instrumenten en gebouwen. Het archief bevat ook manuscripten en wetenschappelijke aantekeningen van verschillende medewerkers, waaronder gedetailleerde aantekeningen van J. Woltjer en M. Schmidt.

Abstract in English

The archive of the Leiden Observatory regarding general management. The archive consists of the correspondence with the Board of Trustees of Leiden University (1837-1945), papers regarding the instruments and the real estate and manuscripts and notes from various staff members, including extensive research notes by J. Woltjer and M. Schmidt.


The inventory consists of the following categories:

Correspondence with the Board of Trustees (no. 1-106)
Observatory Management (no. 107-125)
Instruments (no. 126-156)
Other staff and students (no. 157-186)
Miscellanea (no. 187-190)

To facilitate researchers, each file has been given a short title. In some cases these titles were original designations by the authors. The other titles are mine. The main subject of each file is indicated in the inventory. This is not an exhaustive description, but a first indication, intended for researchers.

Correspondence has been ordered alphabetically by correspondent, following the Dutch system (disregarding prefixes such as van, van der etc).

Within the files, correspondence has been ordered chronologically. Other papers are preserved in the order in which they were found.

"Correspondence with ..." indicates that the file contains letters from both correspondents; "letters from …" indicates that only one side of the correspondence has been preserved in this archive.

Physical Location

Leiden University Library, Special Collections

Custodial History

This archive was created by the successive directors of the Observatory. The papers were preserved in Leiden Observatory until they were transferred to Leiden University Library in 2010.

Immediate Source of Acquisition

The archive was transferred to Leiden University Library in 2010, by agreement between Leiden Observatory, the Leiden University Library and the Department of Documentary Information and Archive Administration of Leiden University.


In several cases, only a selection of the papers of a staff member has been preserved. Large files of routine calculations and observations have not been preserved, while manuscripts and other notes have. The selection was made by David Baneke, advised by Frans van Lunteren and Jan Lub (Leiden Observatory).


Future additions are to be expected.

Existence and Location of Copies

The archive is digitized. The images are available in the inventory.

Related Materials

This archive is part of Leiden Observatory Archives, which contain the papers of the Observatory and its directors from c. 1830-1945.

The collection of Leiden University Library also includes the scientific papers of Jan Oort (director of the Observatory from 1945-1970).


  • Herk, G. van, H. Kleibrink en W. Bijleveld, De Leidse sterrewacht. Vier eeuwen wacht bij dag en nacht (Zwolle 1983).
  • Otterspeer, W., De wiekslag van hun geest. De Leidse universiteit in de negentiende eeuw (Den Haag 1992).
  • Sitter, W. de, Short history of the observatory of the university at Leiden 1633-1933 (Haarlem 1933).

Processing Information

The papers have been reordered and repacked. The original files were maintained as much as possible. Obviously misfiled papers have been refiled, and obviously related papers have been put together, while obviously unrelated papers have been separated.


Collection guide of the Leiden University archives, Observatory, General Management (c. 1829-1992)
Archieven van de Universiteit Leiden - Sterrenwacht, Algemeen
David Baneke, 2010
Language of description
Script of description
Code for undetermined script
Language of description note
Beschrijving is in het Engels.

Revision Statements

  • 3 September 2015: latest update

Repository Details

Part of the Leiden University Libraries Archives & Collections Repository

Witte Singel 27
Leiden 2311 BG Netherlands
+31 71 527 2857