Since 1930 the seat of the museum is in the old palace, restored several times down the centuries, that takes ist name from ist last owners, the Castellanis. The museum displays a very accurate and important collection of scientific instruments, the proof that interest of Florence in science from the 13th century onwards was as great as its interest in art. The collection, or at least the oldest core, originates from the interest of the Medici and Lorraine family in natural, physical and mathematical sciences. It is well known that Cosimo I and Francesco de’ Medici encouraged the scientific and artistic researches in the Gran Ducal workshops, although even Ferdinando II and Cardinal Leopoldo promoted and continued, in the 17th century, physics experiments in the full light of Galileo’s method.

During the 19th century, even Francesco and Pietro Leopoldo of Lorraine continued this type of collection with the aid of qualified specialists like the abbot Felice Fontana (1730-1805), who was appointed to direct and increase the collection of the new Museum of Physics and Natural History inaugurated in 1775. Most of the instruments displayed come from the workshop of the latter museum and are now exhibited on the second floor of the Museum of History of Science that also comprises the old Medici collection originally displayed at the Uffizi. The first floor (11 rooms) is dedicated to the Medici core: quadrants, astrolabus, meridianas, dials, compasses, armillary spheres, bussolas, real works of art made by famous Tuscan and European artists.

The museum also exhibits the Galileo’s original instruments, the thermometers belonging to the "Accademia del Cimento" (1657-1667), the microscopes and meteorological instruments. The second floor (10 rooms) shows a large number of very interesting and beautiful instruments, mostly belonging to the Lorraine family. The Institute of History of Science, close to the museum, owns a very large and old library with lots of research material that is continuously updated. The Institute publishes an internal review on history of science, "Nuncius", besides carrying out permanent research work on history of science and technique, organising exhibitions and publishing monographical work, catalogues of instruments, etc. The institute also has a photographic laboratory, two restoration laboratories and a modern IT laboratory.

THE 18 THEMATIC ROOMS OF THE MUSEUM
Room I
The Medici Collections
Room II
Astronomy and Time
Rooms III and IV
The Representation of the World
Room V
The Science of Navigation
Room VI
The Science of Warfare
Room VII
Galileo’s New World
Room VIII
The Accademia del Cimento: Art and Experimental Science
Room IX
After Galileo: Exploring The Physical and Biological World
Room X
The Lorraine Collections
Rooms XII and XIII
Teaching and Popularizing Science
Room XIV
The Precision Instrument Industry
Rooms XV and XVI
Measuring Natural Phenomena
Room XVII
Chemistry and the Public Usefulness of Science
Room XVIII
Science at