Astronomia/astrologia in un trattato d'abaco della prima metà del QUattrocento (Ms. Mag. Cl XI, 119 della Biblioteca Nazionale di Firenze)

The paper presents the transcription of the chapters devoted to astronomy/astrology in the abbacus treatise contained in the manuscript Magl. Cl. XI, 119 (Florence National Library) written in the first half of the 15 th century. The treatment of this subject in the manuscript differs in many interesting aspects from that in the others so far studied. Among the subjects presented we find: tables to find month to month the day and the hour of the moonrise, a method to calculate the initial day of a month, a rule to build a sundial, lunar prognostica, a table for sailing (tavoletta da navigare). The presence of the last subject is very interesting, its presence in abbacus treatises is in fact very unusual.