In 1643 Bonaventura Cavalieri published *Trigonometria Plana et Sphaerica, Linearis, & Logarithmica, *in which he introduced the concept of logarithms into Italy. The book contained a table of logarithms for numbers up to 1000. The logarithms were given to seven decimal places. Also in this book, he gave a defense of his theory of indivisibles, which had come under attack.

The frontispiece for *Trigonometria.*

On page 29, Cavalieri began his discussion of spherical trigonometry.

For more works by Cavalieri in Mathematical Treasures, see his *Geometria indivisibilibus* and *Exercitationes geometricae sex*.

*These images from its George Arthur Plimpton Collection are presented through the courtesy of the Columbia University Libraries.*