L'astronomie du Moyen Age et ses instruments / Emmanuel Poulle.
Abstract:
During the occidental middle ages, in order to observe the astronomers had only some inaccurate instruments, which were amphibologically called astrolabes and quadrants. In return, their equipment was better for calculations; stereographic and spherical astrolabe, ancient and new quadrant, "saphea", etc. in primum mobile astronomy; "equatorium" in planetary astronomy. This technical situation produced an astronomy more implicated in applying than in replacing the laws set up by the ancient Greeks
Annali dell'Istituto e Museo di storia della scienza di Firenze A. 6, fasc. 2 (1981), p. 3-16