“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:
“In May, that moder is of monthes glade,
That fresshe floures, blewe, and whyte, and rede,
Ben quike agayn, that winter dede made,
And ful of bawme is fletinge every mede;
Whan Phebus doth his brighte bemes sprede
Right in the whyte Bole, it so bitidde
As I shal singe, on Mayes day the thridde,”[78] etc.
The effect of the sun’s declination in causing change of seasons[79] is mentioned a number of times in Chaucer’s poetry. The poet makes a general reference to the fact in a passage of exquisite beauty from Troilus and Criseyde where he says that the sun has thrice returned to his lofty position in the sky and melted away the snows of winter:
“The golden-tressed Phebus heighe on-lofte
Thryes hadde alle with his bemes shene
The snowes molte, and Zephirus as ofte
Y-brought ayein the tendre leves grene,
Sin that the sone of Ecuba the quene
Bigan to love hir first, for whom his sorwe
Was al, that she departe sholde a-morwe.”[80]
More interesting astronomically but of less interest as poetry is his reference to the sun’s declination and its effect on the seasons in the Frankeleyns Tale, because here Chaucer uses the word ‘declination’ and states that it is the cause of the seasons. The reference is the beginning of Aurelius’ prayer to Apollo, or the sun:
“‘Apollo, God and governour
Of every plaunte, herbe, tree and flour,
That yevest, after thy declinacioun,
To ech of hem his tyme and his sesoun,
As thyn herberwe chaungeth lowe or hye;’”[81]
Once again in the Frankeleyns Tale Chaucer refers to the sun’s declination and the passage of the seasons:
“Phebus wex old, and hewed lyk latoun,[82]
That in his hote declinacioun
Shoon as the burned gold with stremes brighte;
But now in Capricorn adoun he lighte,
Wher-as he shoon ful pale, I dar wel seyn.”[83]
Chaucer is here contrasting the sun’s appearance in summer and winter. In his hot declination (his greatest northward declination in Cancer, about June 21) he shines as burnished gold, but when he reaches Capricornus, his greatest southward declination (about December 21) he appears ‘old’ and has a dull coppery color, no longer that of brilliant gold.