Measurements of altitude and geographic latitude in Latin astronomy, 1100–1300

Abstract This article surveys measurements of celestial (chiefly solar) altitudes documented from twelfth- and thirteenth-century Latin Europe. It consists four main parts providing (i) an overview the instruments available for altitude described in contemporary sources, viz. astrolabes, quadrants, shadow sticks, torquetum; (ii) a survey role played by determination geographic latitude, which takes into account more than 70 preserved estimates; (iii) case studies sets measured solar twelfth-century sources; (iv) in-depth discussion evidence relating to performed Paris period 1281–1290. The findings last part indicate that end thirteenth century Parisian astronomer had developed rigorous standards observational practice were typically precision minutes arc with level accuracy higher ± 0;5°, sometimes exceeding 0;1°.