previous next

CHAP. 60. (59.)—THE RAINBOW.

What we name Rainbows frequently occur, and are not considered either wonderful or ominous; for they do not predict, with certainty, either rain or fair weather. It is obvious, that the rays of the sun, being projected upon a hollow cloud, the light is thrown back to the sun and is re- fracted1, and that the variety of colours is produced by a mixture of clouds, air, and fire2. The rainbow is certainly never produced except in the part opposite to the sun, nor even in any other form except that of a semicircle. Nor are they ever formed at night, although Aristotle asserts that they are sometimes seen at that time; he acknowledges, however, that it can only be on the 14th day of the moon3. They are seen in the winter the most frequently, when the days are shortening, after the autumnal equinox4. They are not seen when the days increase again, after the vernal equinox, nor on the longest days, about the summer solstice, but frequently at the winter solstice, when the days are the shortest. When the sun is low they are high, and when the sun is high they are low; they are smaller when in the east or west, but are spread out wider; in the south they are small, but of a greater span. In the summer they are not seen at noon, but after the autumnal equinox at any hour: there are never more than two seen at once,

1 "Manifestum est, radium Solis immissum cavæ nubi, repulsa acie in Solem, refringi."

2 Aristotle treats of the Rainbow much in detail, principally in his Meteor. iii. 2, 3, 4, and 5, where he gives an account of the phænomena, which is, for the most part, correct, and attempts to form a theory for them; see especially cap. 4. p. 577 et seq. In the treatise De Mundo he also refers to the same subject, and briefly sums up his doctrine with the following remark: "arcus est species segmenti solaris vel lunaris, edita in nube humida, et cava, et perpetua; quam velut in speculo intuemur, imagine relata in speciem circularis ambitiûs." cap. 4. p. 607. Seneca also treats very fully on the phenomena and theory of the Rainbow, in his Nat. Quæst. i. 3–8.

3 Vide supra, also Meteor. iii. 2, and Seneca, Nat. Quæst. i. 3.

4 Aristotle, Meteor. iii. 5. p. 581, observes, that the rainbow is less frequently seen in the summer, because the sun is more elevated, and that, consequently, a less portion of the arch is visible. See also Seneca, Nat. Quæst. i. 8. p. 692.

Creative Commons License
This work is licensed under a Creative Commons Attribution-ShareAlike 3.0 United States License.

An XML version of this text is available for download, with the additional restriction that you offer Perseus any modifications you make. Perseus provides credit for all accepted changes, storing new additions in a versioning system.

load focus Latin (Karl Friedrich Theodor Mayhoff, 1906)
hide Places (automatically extracted)

View a map of the most frequently mentioned places in this document.

hide References (3 total)
hide Display Preferences
Greek Display:
Arabic Display:
View by Default:
Browse Bar: