Note 93 — Chapter IV · Terrestrial and Celestial Globes in the Christian Middle Ages
Reading edition
Biographies are numerous. See Dictionary of National Biography, “Roger Bacon,” with bibliographical list. See Bacon’s Opus Magnus, lib. I, 152-153, “necesse est vero mundum extra habere figuram spericam ...”; also lib. IV, in which he treats of the form of the earth.