Moreover, this remarkable rooster observed that the sun had passed the twenty-first degree in Taurus, and we are told elsewhere that he knew each ascension of the equinoctial and crew at each; that is, he crew every hour, as 15° of the equinoctial correspond to an hour: "Wel sikerer was his crowing in his logge, Than is a clokke, or an abbey orlogge. By nature knew he ech ascencioun[69] Of th' equinoxial in thilke toun; For whan degrees fiftene were ascended, Thanne crew he, that it mighte nat ben amended."[70] Chaucer announces the approach of evening by describing the position and appearance of the sun more often than any other time of the day. In the _Legend of Good Women_ he speaks of the sun's leaving the south point[71] of his daily course and approaching the west: "Whan that the sonne out of the south gan weste,"[72] and again of his westward motion in the lines: "And whan that hit is eve, I rene blyve, As sone as ever the sonne ginneth weste,"[73] Elsewhere Chaucer refers to the setting of the sun by saying that he has completed his "ark divine" and may no longer remain on the horizon,[74] or by saying that the 'horizon has bereft the sun of his light.'[75] Chaucer's references to the daily motion of the sun about the earth are apt to sound to us like purely poetical figures, so accustomed are we to refer to the sun, what we know to be the earth's rotatory motion, by speaking of his apparent daily motion thus figuratively as if it were real. Chaucer's manner of describing the revolution of the heavenly bodies about the earth and his application of poetic epithets to them are figurative, but the motion itself was meant literally and was believed in by the men of his century, because only the geocentric system of astronomy was then known. If Chaucer had been in advance of his century in this respect there would certainly be some hint of the fact in his writings. References in Chaucer to the sun's yearly motion are in the same sense literal. The apparent motion of the sun along the ecliptic,[76] which we know to be caused by the earth's yearly motion in an elliptical orbit around the sun, was then believed to be an actual movement of the sun carried along by his revolving sphere. Like the references to the sun's daily movements those that mention his yearly motion along the ecliptic are also usually time references. The season of the year is indicated by defining the sun's position among the signs of the zodiac. The Canterbury pilgrims set out on their journey in April when "the yonge sonne Hath in the Ram his halfe course y-ronne."[77] In describing the month of May, Chaucer does not fail to mention the sun's position in the zodiac: