To knowe the spryng of the dawenyng and the ende
of the evenyng, the whiche ben called the two crepuscules.
Set the nadir of thy sonne upon 18 degrees of height among
thyn almykanteras on the west
syde; and ley thy label on the degre of thy sonne, and than shal the point of thy label
shewen the spryng of the day. Also set the nader of thy sonne
upon 18 degrees of height among thin almykanteras on the est
side, and ley over thy label upon the degre of the sonne, and
with the point of thy label fynd in the bordure the ende of the
evenyng, that is verrey nyght.
The nader of the sonne is thilke degre that is opposyt to
the degre of the sonne, in the 7 signe, as thus: every degre of Aries
by ordir is nadir to every degre of Libra by ordre, and Taurus
to Scorpioun, Gemini to Sagittarie, Cancer to Capricorne, Leo to
Aquarie, Virgo to Piscis. And if eny degre in thy zodiak be
derk, his nadir shal declare hym.
