The Wall Quadrant in Uraniborg

Der Mauerquadrant in Uraniborg, 1909, unbekannter Künstler; Bildquelle: Meyers Großes Konversationslexikon, 6. Aufl., Leipzig 1909, vol. 2, S. 111.

Uraniborg was the research centre of the Danish astronomer Tycho Brahe (1546–1601) on the island of Ven in the Öresund. The castle-like building was divided into three parts: The upper floor contained astronomical equipment and was used for observing the sky; beneath this was a floor with tables for calculation and maps, the mathematical laboratory; and the cellar contained the alchemist's laboratory. One of the reasons for this division and arrangement was Brahe's assumption that the microcosm and the macrocosm correspond to one another: "By looking up, I see downwards; by looking down, I see upwards."

The wall quadrant in Uraniborg, 1909, unknown artist; source: Meyers Großes Konversationslexikon, 6th edition, Leipzig 1909, vol. 2, p. 111.