The paper booklet Brescia, Università Cattolica, Biblioteca di Storia Scienze «Carlo Viganò», E - 3, with two unknown texts on the construction and use of astrolabe (Compositio astrolabii and Modus operandi in astrolabio), shows a double dating and was copied in Bassano del Grappa between February 28th and March 8th 1457.
Keywords: Manoscritti medievali, XV secolo, astrolabio, Brescia, Università Cattolica, Biblioteca di Storia Scienze «Carlo Viganò»; Medieval manuscripts, XVth Century, astrolab