[23]. C. xix.

[24]. Probably from the writings of Isidore, who speaks of the zones as belts on the heavens. Etymologiae, iii, c. xliv; xiii, c. vi; De Natura Rerum, c. x.

[25]. C. xix.

[26]. C. xiii.

[27]. C. xxi.

[28]. C. vi.

[29]. Ibid.

[30]. Ibid.

[31]. The Venerable Bede held that the moon is in some way responsible for the tides. De Natura Rerum, c. xxxix: Migne, Patrologia Latina, XC, 258-259; see also ibid., XC, 422-426 (De Tempore Ratione, c. xxix).

[32]. Alexander Neckam, De Naturis Rerum, 138.