History of the Celsius building

The Celsius building on Svartbäcksgatan is one of Uppsala’s oldest preserved buildings. The building has medieval roots and is recognisable by its slant in relation to today’s street network.

Anders Celsius became Professor of Astronomy in 1730 and subsequently embarked on a study trip that included many of Europe’s leading observatories, such those in Paris, Bologna and Greenwich. Inspired by what he had seen, when he returned Celsius wanted to build a modern facility for observational astronomy in Uppsala.

He therefore wrote a 16-page document in which he argued for the construction of an observatory. He managed to persuade the University Board to pay for the purchase of the building and the construction of an observatory on top of it, which was completed in 1741. The observatory itself, which was a cube-shaped construction atop the building, is no longer there today.

The observatory was equipped with the most advanced instruments of its time, some of which Celsius had purchased on his study trip. These included an astronomical quadrant, a circle sector, and a pendulum clock made by renowned English clockmaker George Graham. Later, a 36-foot telescope and a transit instrument were acquired for the observatory.

From it, Anders Celsius carried out observations of stars, planets and comets. He also studied the Northern Lights, the Earth’s magnetic field, and developed the centigrade temperature scale that later came to bear his name and is used all over the world.

Celsius’s observatory was replaced in 1853 with a newly constructed observatory in the area now known as Observatory Park. In 2000, it was replaced by an observatory on top of the Ångström Laboratory.

Discover more

Anders Celsius – A pioneer in investigating the Earth and its changes