This portrait of a merry author is by Italian artist Francesco Villamena (1564-1624), an engraver and printmaker who became a member of Rome’s prestigious art academy of San Luca in the year of this volume’s publication. The portrait appeared again in 1623 as the frontispiece of Galileo’s Il Saggiatore (The Assayer). Its oval border contains a description of Galileo as a Lyncean, philosopher, and mathematician. Typical of the time and genre, the architectural frame is a nod to classical learning. Two putti (angels) at top hold a telescope and compass, tools of Galileo’s trade; two heads based on classical Roman grotesques, above and below the portrait, suggest themes of imagination and duality of nature.