The primary concern of this manuscript is the study of weights (De Ponderibus) and the effects of gravity, demonstrating the influence of Jordanus of Nemore and Archimedes on Leonardo.

The manuscript also contains drawings of an invention designed to assist in the draining of the Pontine marshes south of Rome, as well as notes on geometry, painting and the flight of birds.

Originally comprised of 96 folios, the homogeneity of the writing style and absence of blank pages in this manuscript confirm that it was produced during a relatively short period of time.