general rewle, ones for evere. And whan thou hast set the degree
of thy sonne up as many almikanteras of heyghte as was the
altitude of the sonne taken by thy rewle, ley over thy label, up-on
the degree of the sonne; and thanne wol the point of thy label
10
sitten in the bordure, up-on the verrey tyd of the day. Ensample
as thus: the yeer of oure lord 1391, the 12 day of March, I wold
knowe the tyd of the day. I took the altitude of my sonne, and
fond that it was 25 degrees and 30 of minutes of heyghte in the
bordure on the bak-syde. Tho turnede I myn Astrolabie, and by-cause