[17] Plutarch: De Facie in Orbe Lunæ, (V, 410).
[18] Young: 109.
[19] Milton: Paradise Lost, Bk. VIII, ll. 82-85.
[20] Vitruvius: De Architectura, Lib. IX, c. 4 (220).
[21] Martianus Capella: De Nuptiis, Lib. VIII, (668).
[22] Ptolemy: Almagest, Lib. I, c. 7, (1, 21-25). Translated in [Appendix B].
[23] Whewell: I, 239.
[24] Whewell: I, 294.
[25] Berry: 79.
[26] His book De Motu Stellarum, translated into Latin by Plato Tiburtinus (fl. 1116) was published at Nuremberg (1557) by Melancthon with annotations by Regiomontanus. Ency. Brit. 11th. Edit.