When Tycho Brahe published a description of his astronomical instruments in 1598 as part of a strategy to procure royal patronage, it was not with one of his grander, precision measurement tools that he opened his account, but rather a small brass quadrant with limited observational utility. The defining feature of this instrument was seemingly a small emblematic image inscribed within the arc of the quadrant. Through this symbolic motif Tycho conveyed a moralising message about the relative worth of astronomy. Considering a range of visual productions that may have influenced his iconography, the present paper situates the quadrant within the broader context of Renaissance visual culture and examines the significance of the quadrant in Tycho’s wider instrument collection.
See for example Allan Chapman“Tycho Brahe – instrument designer, observer and mechanician,”Journal of the British Astronomical Association1989 99:70–76; Allan Chapman “The Accuracy of Angular Measuring Instruments used in Astronomy between 1550 and 1850” Journal for the History of Astronomy 1983 14:133–137; Victor Thoren “New Light on Tycho’s Instruments” Journal for the History of Astronomy 1973 4:25–45; Michael Rosa “How Really Precise and Accurate are Tycho Brahe’s Data?” in Kepler’s Heritage in the Space Age (400th Anniversary of Astronomia nova) edited by A. Hadravová T.J. Mahoney P. Hadrava (Prague: National Technical Museum 2010) pp. 102–113; Gudrun Wolfschmidt “The Observatories and Instruments of Tycho Brahe” in Tycho Brahe and Prague: Crossroads of European Science (Frankfurt am Main: Deutsch 2002) pp. 203–216; G.L. Tupman “A Comparison of Tycho Brahe’s Meridian Observations” The Observatory 1900 23:132–135; Walter G. Wesley “The Accuracy of Tycho Brahe’s Instruments” Journal for the History of Astronomy 1978 6:42–53. A notable exception is Adam Mosley’s Bearing the Heavens: Tycho Brahe and the Astronomical Community of the Late Sixteenth Century (Cambridge: Cambridge University Press 2007) whose examination of Tycho’s modes of communication highlights the extent to which Tycho utilised his instruments to convey his ideas alongside more conventional media such as books and letters. See also Volker Remmert “Visual Legitimisation of Astronomy in the Sixteenth and Seventeenth Centuries: Atlas Hercules and Tycho’s Nose” Studies in History and Philosophy of Science 2007 38:327–362 which calls attention to the iconography of Tycho’s great equatorial armillary.