Treatise on The Astrolabe : addressed to his son Lowys / by Geoffrey Chaucer ; edited from the earliest MSS. by Walter W. Skeat

[folio 15b]

15. To know which day is lik to wych day as of lengthe, &c.

[Ad cognoscendum quales dies in longitudine sunt similes.]

¶ Loke whiche degrees ben illik fer fro the heuedes of Cancer & Capricorn̛ ; & lok, whan the sonne is in any of thilke degrees, than ben the dayes ilike of lengthe. ¶ this is to seyn, þat as long is þat day in þat Monthe, as was swych a day in swich a month ¶ ther variet[h] but lite. ¶ Also yif þow take 2 daies naturaly in the yer ilike fer fro eyther pointe of [the] equinoxial in the opposit parties, ¶ than as long is the day artificial of þat on day / as is the nyht of þat othere, & the contrarie. ¶ & for [the] more declaracioun, lo here thi figure.