Leiden Observatory is an astronomical observatory in the city of Leiden, the Netherlands. The observatory was located on the university building in the centre of Leiden before a new observatory building. It remained there until 1974 when the department moved to the science campus north-west of the city, a number of notable astronomers have worked or directed the observatory including Willem de Sitter, Ejnar Hertzsprung, and Jan Oort. The observatory was one of the first purpose-built observatories in Europe, though Golius used the observatory regularly, no publications came from its use by him. It is not known whether Golius had any other than Snellius quadrant at the observatory. In 1682 Burchardus de Volder became professor of mathematics at the university, during his tenure the observatory was enlarged, including a second turret to house a brass sextant which he purchased, and the rebuilding of the old turret. For the next two years Lotharius Zumbach de Coesfeld ran the observatory until his appointment as professor of mathematics in Kassel in 1708, between then and 1717 the observatory went without a director until Willem s Gravesande was appointed director. During his time at the observatory, s Gravesande purchase a number of new instruments including new telescopes and tools, S Gravesandes successor was Johan Lulofs who used the observatory to observe Halleys comet in 1759 and solar transits of Mercury in 1743 and 1753 and Venus in 1761. In November 1768 when Lulofs died, Dionysius van de Wijnpersse took over responsibility for the observatory until Pieter Nieuwland became its director in 1793 for a year until he died in 1794. For a number of years the curators attempted to find a suitable astronomer to look after the observatory, eventually employing Jan Frederik van Beeck Calkoen in 1799, in 1817 the observatory towers were pulled down and rebuilt. Kaiser also acquired a number of new instruments and telescopes with which he made observations including that of comets, planets, and binary stars. As a result of the increased interest in astronomy brought about due to Kaisers popular writings and teachings, from 1859 to 1909 the Netherlands civil time was set according to the local civil time at the observatory, communicated using the telegraphic network. In the early 19th Century the observatory formed an agreement with Union Observatory to allow researchers use of both facilities. The first visitor from Leiden was Ejnar Hertzsprung, by 1860 the new observatory building was completed. The new building was constructed in a side of the city inside the university’s botanical gardens. It consisted of a number of offices, living quarters for astronomers, in 1873 two new rooms were added to the building in order to house the tools required to verify nautical instruments, tools used to test compasses, sextants and other instruments. Two of the domes were rebuilt, one in 1875 and the other in 1889. More new buildings were constructed before the end of the 19th century including the Western tower in 1878, one to the East in 1898, in 1896 the observatory purchased their first photographic telescope, with a dome being built to house it between then and 1898
Drawing of Leiden Observatory in 1670, seen on top of the university building.
The second building to house the Leiden Observatory (built in 1860). This building now houses part of the law faculty. Two of the optical telescope domes can be seen on the roof.
Image: Erfgoed Leiden LEI001016349 Panorama vanaf de Sterrenwacht
Image: NIMH 2011 0300 Aerial photograph of Leiden, The Netherlands 1920 1940