Besides mentioning the heavenly bodies in time references and figurative allusions, Chaucer also employs them often in descriptions of day and night, of dawn and twilight, and of the seasons. It is with a poet's joy in the warm spring sun that he writes: "Bright was the day, and blew the firmament, Phebus of gold his stremes doun hath sent, To gladen every flour with his warmnesse."[55] and with a poet's delight in the new life and vigor that nature puts forth when spring comes that he writes the lines: "Forgeten had the erthe his pore estat Of winter, that him naked made and mat, And with his swerd of cold so sore greved; Now hath the atempre sonne al that releved That naked was, and clad hit new agayn."[56] Chaucer's astronomical allusions, then, except in the _Treatise on the Astrolabe_ and in his translation of _Boethius de Consolatione Philosophiae_, in which a philosophical interest in celestial phenomena is displayed, are almost invariably employed with poetic purpose. These poetical allusions to heavenly phenomena, however, together with the more technical and detailed references in Chaucer's prose works give evidence of a rather extensive knowledge of astronomy. With all of the important observed movements of the heavenly bodies he was perfectly familiar and it is rather remarkable how many of these he uses in his poetry without giving one the feeling that he is airing his knowledge. 1. _The Sun_ Of all the heavenly bodies the one most often mentioned and employed for poetic purposes by Chaucer is the sun. Chaucer has many epithets for the sun, but speaks of him perhaps most often in the classical manner as Phebus or Apollo. He is called the "golden tressed Phebus"[57] or the "laurer-crowned Phebus;"[58] and when he makes Mars flee from Venus' palace he is called the "candel of Ielosye."[59] In the following passage Chaucer uses three different epithets for the sun within two lines: "The dayes honour, and the hevenes ye, The nightes fo, al this clepe I the sonne, Gan westren faste, and dounward for to wrye, As he that hadde his dayes cours y-ronne;"[60] Sometimes Chaucer gives the sun the various accessories with which classical myth had endowed him--the four swift steeds, the rosy chariot and fiery torches: "And Phebus with his rosy carte sone Gan after that to dresse him up to fare."[61] "'now am I war That Pirous and tho swifte stedes three, Which that drawen forth the sonnes char, Hath goon some by-path in despyt of me;'"[62] "Phebus, that was comen hastely Within the paleys-yates sturdely, With torche in honde, of which the stremes brighte On Venus chambre knokkeden ful lighte."[63]