Fig. 3. Paris, Bibliothèque nationale, MS fr. 19093, fol. 20v, (c. 1220/35), detail of man sighting height of tower using an instrument - an isosceles right triangle mounted on feet (built of wood?), reproduced with permission from Lassus, Album de Villard, 1858, reprint, Paris, Éditions Léonce Laget, 1976. return to text |