Courtyard of Teylers Foundation House with the observatory

The Teylers astronomical observatory (Dutch: Teylers Sterrenwacht) is an

astronomical observatory An observatory is a location used for observing terrestrial, marine, or celestial events. Astronomy, climatology/meteorology, geophysical, oceanography and volcanology are examples of disciplines for which observatories have been constructed. His ...

built in 1784 on the roof of the

Oval Room The Oval Room in the Teylers Museum was the first part of the museum (though it was not called a museum yet) that was opened in 1784. It could be entered through the garden of the fundatiehuis, the former home of Pieter Teyler van der Hulst. The ...

of the Teylers Museum in

Haarlem Haarlem (; predecessor of ''Harlem'' in English) is a city and municipality in the Netherlands. It is the capital of the province of North Holland. Haarlem is situated at the northern edge of the Randstad, one of the most populated metropoli ...

.Teylers Museum
about the observatory. (Dutch)

History

The observatory was built on the suggestion of

Jacobus Barnaart Jacobus Barnaart (6 October 1726 in Haarlem - 2 November 1780 in Haarlem) was a Dutch merchant and one of the five first directors of the Teylers Stichting. Barnaart, son of Jacobus Barnaart and Margaretha van Elten, was born in a relatively ric ...

, one of the five initial directors of the

Teylers Stichting The Teylers Stichting (English: Teylers Foundation) is a Dutch foundation founded with the heritage of the Dutch 18th century cloth merchant and banker Pieter Teyler van der Hulst to support the people in need and encourage worship, science and art ...

, which was the foundation responsible for taking care of the inheritance of

Pieter Teyler van der Hulst Pieter Teyler van der Hulst (25 March 1702 – 8 April 1778) was a wealthy Dutch Mennonite merchant and banker, who died childless, leaving a legacy of two million florins (in today's terms: about EUR 80 million) to the pursuit of religion, art ...

. Barnaart was an amateur scientist who had a great interest in astronomy and wanted to build a state-of-the-art astronomical observatory on the roof of the Oval Room. This proved to be a bad idea, because the roof was made of wood, which transfers too many vibrations to make reliable and precise observations. Hence a belvedère was built instead, a square tower with two doors in each wall. Though the observatory couldn't be used for precision measurements, it was still used for manual observations. The collection of the Teylers physical cabinet contains several telescopes and other devices that were used. Until 1817 the observatory also had a camera obscura, which was used for drawings of the view from the little tower.photo of the removal of the staircase in the process or renovation
/ref>Teyler 1778-1978. Studies en bijdragen over Teylers Stichting naar aanleiding van het tweede eeuwfeest (Haarlem / Antwerpen 1978), p 189 Though they have not survived, the Teylers archives have evidence that

Vincent Jansz van der Vinne Vincent Jansz. van der Vinne (1736, Haarlem – 1811, Haarlem), was a Dutch 18th century painter and the great-grandson of Vincent van der Vinne. Biography According to the RKD he was a pupil of his father Jan Laurentsz van der Vinne, who ...

was paid 86 guilders for painting the "walls and ceilings of the cupula". That was not the only artwork that early stargazers met with when they climbed the stairs. On the rooftop of the first staircase a vase was installed that was delivered by

Jan Woortman Jan, JaN or JAN may refer to: Acronyms * Jackson, Mississippi (Amtrak station), US, Amtrak station code JAN * Jackson-Evers International Airport, Mississippi, US, IATA code * Jabhat al-Nusra (JaN), a Syrian militant group * Japanese Article Numb ...

in 1781. Though lost since, the vase can be seen in the painting of the courtyard of the Foundation house by Wybrand Hendriks. The vase was the trademark of Teyler, and is visible on the top of Van Marum's electrostatic generator as well. The observatory can be reached via a staircase from the Grote Herenkamer (large board room), which is located next to the Oval Room. That staircase leads the visitor to the lower roof, where a steep open air wooden staircase leads to the small room on top of the dome. For precision measurements, a new observatorium was built in the garden, that was later used as a studio by the later curator

Jan van Borssum Buisman Jan Hendrik van Borssum Buisman (1919, Haarlem – 23 February 2012, Haarlem), was a 20th-century painter from the Netherlands. Biography According to the RKD he was the son of Hendrik van Borssum Buisman.Teylers Museum 18th-century architecture in the Netherlands nl:Teylers Museum#Sterrenwacht