hanging on a lyne heyer than thin heved on a perche; and thilke

lyne mot hange evene perpendiculer by-twixe the pool and thyn

eye; and thanne shaltow seen yif A sitte evene over the pool and

30

over F at evene; and also yif F sitte evene over the pool and

over A or day. And for more declaracion, lo here thy figure.

[24.] Another conclusioun to prove the heyghte of the pool artik fro the orisonte.

[Alia conclusio ad probandum altitudinem de polo artico ab orizonte.]

Tak any sterre fixe that nevere dissendeth under the orisonte in

thilke regioun, and considere his heyest altitude and his lowest