[659] “This small star.” Par. vi. 112.
[660] Conv. II. xiv. 92-98.
[661] The Frankfort printed edition and some Latin MSS of Alfraganus agree with this: the edition of Golius gives ¹/₁₈.
[662] Almagest, Bk. IX.
“This heaven, where ends the shadowy cone Cast by your world.” Par. ix. 118, 119. (Longfellow).
[664] Rabbi Abraham ben Chija, in his Sphæra Mundi, written about 1100 a.d., says that Earth’s shadow extends as far as the distance of Mercury, not of Venus (Delambre, Histoire de l’astronomie ancienne, and Dreyer, Planetary Systems); but this does not agree with the figures given by Alfraganus.
[665] Her diameter would look no larger than the diameter of Saturn, as we see it when nearest to him; but like Saturn she would be visible as a bright point, because shining by reflected sunlight. Ancient and mediæval astronomers never realized this, however, but thought of Earth as a dark body, receiving light but giving none.
[666] Conv. II. xiv. 126, 127; Par. x. 40-42, 48.
[667] Par. xxii. 67; xxxi. 19-24; xxx. 118-123.