<p style='text-align: justify;'>Johannes Bayer (1572-1625) was educated at the University of Ingolstadt and became legal advisor to the City Council of Augsburg in 1612. The illustrated celestial atlas, the <i>Uranometria</i>, was sponsored by the humanist-patrician, Marc Welser (1558-1614) and published in Augsburg in 1603. It contains twenty-nine maps of the sky engraved by Alexander Mair (c. 1559-1617) showing about 2,000 stars. The book is dedicated to leaders of the City Council of Augsburg. In his address to the reader, Bayer explains that he wished to rectify the confusion caused by the plethora of names for stars since antiquity. In particular, the book takes account of descriptions from Hipparchus, Ptolemy, the <i>Alphonsine Tables</i>, and Copernicus collated by Tycho Brahe (and circulating in manuscript form at the time), which Bayer had studied carefully. Bayer shows no interest in engaging with the different cosmological theories of his time. This is a typically humanist work seeking to establish a proper correspondence between 'names and things'. Some copies feature both the figures and accompanying text, while the images and words are separated into two volumes in other instances. In addition to the forty-eight Ptolemaic constellations, <i>Uranometria</i> features twelve new constellations of the southern skies and two planispheres giving an overview of the northern and southern hemispheres, respectively. Each engraving is framed with celestial co-ordinates and includes lines for the equinoctial circles, a shaded band for the zodiac, and a dotted region for the Milky Way in the background. Constellations are presented in their classical forms 'for the lovers of antiquity'. These figures made the book 'well suited for playing the humanistic parlor game of deciphering iconographic concepts', according to Volker Remmert. Each star is allotted a Greek letter, followed by Latin letters, collated with the traditional numbers. In a legend for each table, Bayer gave all the known names of a given constellation, and grouped the stars according to their magnitude. '<i>Cassiopeia</i>' is the tenth table in Uranometria. Bayer notes that the constellation is called Cassiopeia by many authors, 'a soft chair' by Juvenal, and is also known by other names, such as chair, seat, throne, royal chair. It is also described as holding a thick palm. In Greek, it is also called a throne or a chair, 'abenezra' in Hebrew and '<i>Canis</i>' or '<i>Cerua</i>'. The constellation's 'joints' (<i>diarthrosis</i>), by which Bayer means the stars that hold together the shape of a constellation, are twenty-five, ranging from the third to the sixth magnitudes. B, the large star at the back of the seat is labelled as 'alien' (<i>peregrina</i>) to the constellation. This is Tycho Brahe's 'new star' of 1572. Bayer quotes from Brahe's <i>Progymnasmata</i> to explain how the brightness of this star changed over time ' originally as bright as Venus in November 1572, dimming a little in December and January 1573, but brightening up to equal the stars of the second magnitude, before gradually fading away by February 1574. It was stationary at the southern edge of the Milky Way, and formed almost a complete lozenge shape with alpha, beta and gamma of this constellation. Bayer also noted that because there was no parallax, the size of the new star could be computed to 361 ½ times that of the Earth, and 2 2/3 times that of the Sun, assuming that the Sun is no greater than 139 to 140 times the size of the Earth (the actual diameter of the Sun is about 109 times that of the Earth).</p>
