All quotations from Dante’s works are taken from Moore’s Tutte le Opere di Dante Alighieri, 3rd edition, Oxford 1894.

Astronomical data are chiefly taken from Young’s Manual of Astronomy, and the Nautical Almanac.

CONTENTS.

INTRODUCTION 1
PART I.
ASTRONOMY FROM PRIMITIVE TIMES UNTIL
THE AGE OF DANTE.
I.Apparent Movements of the Heavenly Bodies as seen from Earth[ 9]
II.The Beginnings of Astronomy.
Gnomons and clepsydras; the constellations and the calendar; astrology and star-worship; early cosmogonies[25]
III.Greek Astronomy: First Period. b.c. 900 to b.c. 350
1. Homeric Greece; First Notions of Astronomy[51]
2. Thales and Anaximander: Earth flat, heaven a series of hemispheres[55]
3. Later Flat Earth Systems: the Universe a sphere[60]
4. Pythagoras and his Followers: Earth round, Earth in Motion[66]
IV.Greek Astronomy: Second Period, b.c. 400 to a.d. 150
1. Plato: the World-Soul[79]
2. Eudoxus: the Spheres[88]
3. Calippus: the Spheres of Eudoxus improved[93]
4. Aristotle: the Philosophy of the Spheres; the three kinds of motion;
 Earth immoveable at the centre of the Universe;
 the elements; the celestial movers, and the First Mover[95]
5. Aristarchus: Earth turning on her axis, and revolving round the sun[107]
6. The School of Alexandria: instruments and methods;
 Earth’s diameter measured; the theory of Moveable Eccentrics[112]
7. Hipparchus: “the Father of Astronomy;” his star catalogue;
 his inventions and discoveries; the precession of the equinoxes[122]
8. Ptolemy: the Almagest; the system of Epicycles and Eccentrics;
 distance and size of the moon discovered; the stars;
 astrology; geography, the seven climates[134]
V.Retrospect: Greek Cosmogonies; Greek calendar[159]
VI.Astronomy under Imperial and Christian Rome.b.c. 46 to a.d. 1000.
 Amateur Astronomers; the Julian Calendar; passion for Astrology; the
 Fathers; the ecclesiastical Calendar; the Schools; the Monasteries[167]
VII.Arab Astronomy. a.d. 750 to 1250.
 Schools of Baghdad, Egypt, Spain. Improvements in Mathematics
 and Instruments; Ptolemy’s values more correctly determined;
 supposed discoveries of planetary distances and trepidation;
 a ninth sphere added to Ptolemy’s eight[181]
VIII.The Return of Greek Astronomy to Europe. a.d. 1000 to 1300.
 The Universities; Arab influence; Greek books; new European books;
 the course in Astrology in Bologna; Aristotle and the Church[199]
PART II.
THE ASTRONOMY OF DANTE.
I.Popular Astronomy in Italy in Dante’s Time.
 The astronomy of Dante contrasted with Homer and Milton.
 General feeling for astronomy in his day; some famous
 astrologers: astronomy considered an ennobling study;
 Ptolemy’s system final. Knowledge of average educated man.[209]
II.Dante’s Studies.
 Dante a representative of contemporary beliefs: his erudition;
 his education; Brunetto Latini’s influence; possible visits to
 universities of Bologna, Padua, Paris.[223]
III.Books on Astronomy used by Dante.
 Dante’s wide reading; his diligence and memory. Ptolemy his
 supreme authority on astronomy; his principal text-books
 Alfraganus and Aristotle; versions used. Classical Latin authors;
 Greek; Arab; Christian[231]
IV.Astronomy in Dante’s Writings.
 References to heavenly bodies in Vita Nuova, the Canzoniere,
 Convivio, Latin works and letters, Divine Comedy. Artistic use
 of the facts and theories of astronomy.[253]
V.Observational Astronomy
 1. Movements of the Moon[261]
 2. Movements of the Sun[270]
 3. The Stars[283]
 4. The Galaxy[303]
 5. The Planets[307]
 6. Eclipses[316]
 7. Comets and Meteors[318]
 8. The Sun’s Path in the Sky seen from different Parts of the Earth[322]
 9. Celestial Phenomena and Time[338]
VI.Dante’s Journey through the Three Realms:
Indications of Time and Direction by Means of the Skies
 1. Time references in the Divine Comedy[353]
 2. The Inferno[367]
 3. Purgatory[373]
 4. Paradise[391]
 5. Positions of Sun, Moon, and Planets among the Stars during Dante’s Vision[402]
 6. The Assumed Date of the Vision[409]
VII.Theoretical and Speculative Astronomy
 1. The Spheres[429]
 2. The Spheres and the four Elements[441]
 3. Dimensions and Physical Nature of the Universe[457]
 4. Influence of the Spheres on Human Affairs[471]
 5. The Motive Power[480]
VIII.Mediæval and Modern Views of the Universe[487]