1. Details are given in my “Hipparchus-Geminus-Galileo,” Studies in the History and Philosophy of Science 20 (1989), pp. 47-56.
2. Letter from Descartes to Marin Mersenne, 11 October 1638. Translated in Stillman Drake, Galileo at Work (Chicago, 1978 ), pp. 387 - 88.
3. Johannes Kepler, Mysterium Cosmographicum (Tübingen, 1596), trans. A. M. Duncan as Mysterium Cosmographicum: Secret of the Universe (New York, 1981), esp. pp. 85-105.
4. Benedetti’s proposition is translated in I. E. Drabkin and Stillman Drake, Mechanics in Sixteenth-Century Italy (Madison, 1960), pp. 147-53, as it first appeared in Venice in 1533.
5. Translated in Stillman Drake, “A Neglected Galilean Letter,” Journal of the History of Astronomy 17 (1987),pp. 93-105.