Another conclusioun to prove the latitude of the
regioun.
Understond wel that the latitude of eny place in a regioun is
verrely the space bytwixe the cenyth of hem that dwellen there
and the equinoxiall cercle north or south, takyng the mesure in
the meridional lyne, as shewith in the almykanteras of thin
Astrelabye. And thilke space is as much as the pool artike is
high in that same place fro the orisonte. And than is the
depressioun of the pool antartik, that is to seyn, than is the
pool antartik, bynethe the orisonte the same quantite of space
neither more ne lasse.
Than if thou desire to knowe this latitude of the regioun,
tak the altitude of the sonne in the myddel of the day, whan the
sonne is in the hevedes of Aries or of Libra; for than moeveth
the sonne in the lyne equinoxiall; and abate the nombre of that
same sonnes altitude out of 90 degrees, and than is the remenaunt
of the nomhre that leveth the latitude of the regioun. As thus:
I suppose that the sonne is thilke day at noon 38 degrees of
height; abate than 38 degrees oute of 90; so leveth there 52;
than is 52 degrees the latitude. I say not this hut for ensample;
for wel I wot the latitude of Oxenford is certeyn minutes lasse;
thow might preve the same.
Now yf so be that the semeth to longe a tarieng to abide til
that the sonne be in the hevedes of Aries or of Libra, than wayte
whan the sonne is in eny othir degre of the zodiak, and considre
the degre of his declinacioun fro the equinoxiall lyne; and if
it so be that the sonnes declinacioun he northward fro the
equinoxiall, abate than fro the sonnes altitude at non the nombre
of his declinacioun, and than hast thou the height of the hevedes
of Aries and Libra. As thus: My sonne is peraventure in the 10
degre of Leoun, almost 56 degrees of height at non, and his
declinacioun is almost 18 degrees northward fro the equinoxiall;
abate than thilke 18 degrees of declinacioun out of the altitude
at non; than leveth there 38 degrees and odde minutes. Lo there
the heved of Aries or Libra and thin equinoxiall in that regioun.
Also if so be that the sonnes declinacioun be southward fro the
equinoxiall, adde than thilke declinacioun to the altitude of the
sonne at noon, and tak there the hevedes of Aries and Libra and
thin equinoxial; abate than the height of the equinoxial out of
90 degrees; than leveth there the distance of the pool of that
regioun fro the equinoxiall. Or elles, if the list, tak the
highest altitude fro the equinoxial of eny sterre fix that thou
knowist, and tak his netherest elongacioun (lengthing) fro the
same equinoxial lyne, and work in the manere forseid.
