Alessandro Piccolomini’s Early Astronomical Works: II. An Examination of Their Scientific Content

Dr Elly Dekker is a Dutch astronomer and science historian, specialising in the history of astronomy. She studied theoretical physics at Utrecht University. In 1975, she obtained a PhD. in astronomy at Leiden University with the thesis Spiral structure and the dynamics of flat stellar systems supervised by Hendrik C. van de Hulst.From 1978-88 she was curator at the Museum Boerhaave in Leiden. After 1988 she worked as an independent scholar on the history of astronomical models and instruments. From 1993-1995 she was Sackler fellow of the Royal Museums Greenwich. She was awarded the Caird Medal for her work on the museum’s globe collection in 1998. Her books include The Leiden Sphere. An exceptional seventeenth-century planetarium (Leiden, 1987); with Peter van der Krogt, Globes from the Western World (Zwemmer, London, 1993); Globes at Greenwich. A Catalogue of the Globes and Armillary Spheres in the National Maritime Museum, Greenwich (Oxford, Greenwich, 1999); Istituto e Museo di Storia della Scienza: Catalogue of Orbs, Spheres and Globes (Florence, 2004); and Illustrating the Phaenomena: Celestial Cartography in Antiquity and the Middle Ages (Oxford, 2013). Her papers comprise studies on the discovery of the southern celestial sky, on medieval astrolabes and quadrants, on Renaissance globes, and on the history of Renaissance celestial maps.

• 1. De la Sfera del Mondo: an exploration of Piccolomini’s universe.- 1.1 Introduction.- 1.2 Piccolomini and the motion of the solar apogee.- 1.3 The sizes of the planets and their distances from the Earth.- 1.4 Concluding remarks.- 2. De le Stelle Fisse: teaching the constellations.- 2.1 Historical notes.- 2.2 Piccolomini’s method.- 2.3 Piccolomini’s new invention.- 2.4 Concluding remarks.- 3. Manuscript notes made by readers of De le Stelle Fisse.- 3.1 Cartographical uses: a 1553 edition of De le Stelle Fisse in the Museo Galileo, Florence.- 3.1.1 The coordinate grids.- 3.1.2 Use of the maps to chart the path of the comet of 1652-53.- 3.2 Use of the maps to outline constellation figures: a 1570 edition from the Collegio Romano.- 4. The maps in De le Stelle Fisse.- 4.1 Introduction to the maps.- 4.2 Construction of the maps.- 4.3 The globe hypothesis.- 4.4 Piccolomini’s system for indicating direction and orientation.- 5. The Tables in De le Stelle Fisse.- 5.1 An introduction to Piccolomini’s Tables.- 5.2 The daily motion of a star: the relationship between altitude and azimuth.- 5.3 Calculating zenith distance and azimuth.- 5.4 Piccolomini’s Tables and the motion of the Sun.- 5.5 Concluding remarks.- 6. Simultaneous risings and settings in De le Stelle Fisse.- Appendix I: The constellation guide.- Appendix II: Map features in the different editions of De le Stelle Fisse.- Appendix III: Explanations of the names and terms used.- Bibliography.- Index.