under the pol and under F; for sothly, than wol F sitte over the pool,

and A wol sitte under the pool. Tak than eft-sones the altitude of

A from the orisonte, and note as wel his secounde altitude as his

firste altitude; and whan that this is don, rikne how manye degrees

that the firste altitude of A excedeth his seconde altitude, and tak

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half thilke porcioun that is exceded, and adde it to his seconde

altitude; and tak ther the elevacioun of thy pool, and eke the

latitude of thy regioun. For thise two ben of a nombre; this is

to seyn, as many degrees as thy pool is elevat, so michel is the