BALIANI, Giovanni Battista (1582-1666). De motu naturali gravium solidorum et liquidorum. Genoa: Giovanni Maria Farroni, 1646.

Unpressed copy of the second, expanded, edition—the first to contain "an important step toward the concept of mass and the analysis of acceleration" (DSB). The first edition of this book on motion and freefall was published in 1638. This second edition is enlarged, including a treatment of fluid motion and speculation on "the possibility that in unmeasurably small successive finite times, the spaces traversed by a falling body might increase in proportion to the natural numbers" (DSB). Baliani was a correspondent of Galileo, whom he visited in Florence in 1615. Carli and Favaro 210; Cinti 117; Roberts and Trent p 20.

Quarto (194 x 137mm). Woodcut device on title, diagrams in text, woodcut initials and ornaments (faint dampstaining around outer edges of some pages, a few spots). Later stiff vellum, speckled edges. Provenance: occasional early underlining – Franklin Institute (bookplate and stamp).