To knowe sothly the degre of the longitude of the mone, or
of eny planete that hath no latitude for the tyme fro the
ecliptik lyne.
Tak the altitude of the mone, and rekne thy altitude up among
thyn almykanteras on which syde that the mone stondith, and set
there a prikke. Tak than anon-right upon the mones syde the
altitude of eny sterre fix which that thou knowist, and set his
centre upon his altitude among thyn almykanteras there the sterre
is founde. Wayte than which degre of the zodiak touchith the
prykke of the altitude of the mone, and tak there the degre in
which the mone stondith. This conclusioun is verrey soth, yf the
sterres in thin Astrelabie stonden after the trouthe. Comoun
tretes of the Astrelabie ne maken non excepcioun whether the mone
have latitude or noon, ne on wheyther syde of the mone the
altitude of the sterre fixe be taken.
And nota--> that yf the mone shewe
himself by light of day, than maist thou worche this same
conclusioun by
the sonne, as wel as by the fixe sterre.
