research > cartography > Joining the Dots
Anthony Auerbach

‘Joining the Dots: The Historical Appearance of “Geometric” Constellation Figures’, research project by Anthony Auerbach.

Bayer: Triangulum

Linking the brightest stars with straight lines on a map to form quasi-geometric figures is probably the form of the constellations most familiar to contemporary visual culture. Although it is widely assumed to be the essential, the original, even the ‘natural’ way of drawing the constellations, this form was not widely adopted before the nineteenth century. It became the norm in the twentieth century, where constellation figures survived, but was never officially sanctioned [note 2].

The earliest printed map to propose a system of ‘geometric’ constellation figures to replace the traditional figurative star signs appears to be the Nouvelle Uranographie (1786) by Alexandre Ruelle [note 3]. Unlike other attempts at the reform of the constellations such as Schiller’s Coelum Stellatum Christianum (1627) [note 4], the Nouvelle Uranographie was a success. As a result, this map lost its place in history. Whereas the various failed attempts at reform are still admired as historical curiosities — that is to say, as objects without consequences — the Nouvelle Uranographie falls into history's blind spot.

The history of celestial cartography is usually thought to have come to an end at the turn of the nineteenth century. Johann Bode’s Uranographia (1801) is widely regarded as the last and most magnificent star atlas in the tradition which reaches back to Ptolemy. Bode’s atlas is a museum of astrography [note 5]. It not only aggregated the sum of observational data and cartographic customs, but augmented the latter with several new constellation figures. After Bode, the antiquarians note with regret, star maps display either the triumph of professional science over the art of cartography, or the vulgarisation of amateur astronomy, served increasingly with cheap, industrially produced maps, books, gadgets and toys.

On this view, the Nouvelle Uranographie would appear as a premature announcement of the end of celestial cartography’s ‘golden age’ and would thus tend to deprive the standard history of its culmination.

Acknowledging the novelty of the Nouvelle Uranographie, however, would tend to deprive subsequent maps of the primordial authority of ‘geometric’ figures invoked by the promoters of such maps (if not by historians) — those figures which according to Galileo’s assertion [note 6] are the characters in which the book of the universe is written and in which philosophy shall be read.

Nonetheless, Ruelle’s map is marked by the history in which it was eventually engulfed. Having first appeared in 1786 bearing a royal dedication, the map’s alterations and resurfacings (authorised or plagiarised) record the upheavals which revolutionised not only the affairs of state, but also the regime of what was soon to become the Observatoire de la République. By 1795, Ruelle himself appears to have abandoned the institution that had once been his refuge, ‘la révolution l’ayant enlevé à l’astronomie’ [note 7].

Research will disclose the historical juncture in which the Nouvelle Uranographie emerged — at the convergence of astronomy and cartography which dominated the activities of the Paris Observatory in the eighteenth century; at the divergence of amateur and professional astronomy which came to dominate map production in the nineteenth century; at the submergence of speculative histories of astronomy that were discredited even as the map’s innovation was accepted — as well as how the writing of history swept the map and its author into obscurity.

Interpretation faces an anomalous object. Like the figures which lend form to discrete astronomical data, interpreting the Nouvelle Uranographie will have to deal with loose ends and disconnected facts: with historical dead-ends. It will risk being led by Ruelle — whose name in French means back alley — away from the main street of history.

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  1. John Keill, An Introduction to the True Astronomy: Or, Astronomical Lectures, London: Bernard Lintot, 1730, p. 27. Italics in the original. [back to text]
  2. The International Astronomical Union had, at its founding in 1919, nominated the eighty-eight constellations that would be officially recognised and rigourously defined by their boundaries. The task of the scientific definition of the constellations was entrusted to Eugène Delporte and published in the Délimitation scientifique des constellations (Cambridge University Press, 1930). The boundaries defined on Delporte’s map according to the geometric division of the sphere into parallels and meridians are the vestigial outlines of a tradition it was Delporte’s task both to liquidate and to uphold. [back to text]
  3. Alexandre Ruelle, Nouvelle Uranographie ou Méthode très facile pour apprendre à connoitre les Constellations, (Paris: Dezauche, de la Marche et Jombert, 1786). [back to text]
  4. Julius Schiller, Coelum Stellatum Christianum (Augsburg: Andreae Apergeri, 1627). [back to text]
  5. Johann Elert Bode, Uranographia (Berlin: Frederico de Haan, 1801). The atlas featured Ptolemaic and non-Ptolemaic constellations as well as ecliptic and equatorial graticules. The western tradition of printed maps stems from the Renaissance. [back to text]
  6. Galileo Galilei, The Assayer (Garden City, NY: Doubleday, 1957), pp. 237–238. [back to text]
  7. Jérôme de Lalande, Bibliographie astronomique avec l'histoire de l'astronomie depuis 1781 jusqu'à 1802 (Paris: Impimerie de la République, 1803), p. 596. [back to text]


Triangulum from Johann Bayer, Uranometria (Augsburg, 1603)