The following is the final inside look at the current exhibition in Princeton University Library’s Ellen and Leonard Milberg Gallery in Firestone Library: “The Most Formidable Weapon Against Errors: The Sid Lapidus ’59 Collection & the Age of Reason.” The exhibition closes this Sunday, June 8, 2025.

Curated by Steven A. Knowlton, Librarian for History and African American Studies, the exhibition celebrates the collecting achievements of Sid Lapidus, Class of 1959, who has devoted many years to the acquisition of rare books that trace the emergence of Enlightenment ideas and their influence on politics, medicine, and society, creating a powerful tool for understanding the ideas that have shaped modern American society. 

The Enlightenment era’s emphasis on observation as the key to knowledge is the foundation of modern science. From earlier detailed observations of astronomical phenomena to the detection of subatomic particles, the Lapidus collection—in works concentrated in the New York Historical and the American Antiquarian Society—offers glimpses of the progression from the astrolabe to the nuclear bomb.

(Image at top right) A tool of astronomers in the 18th century was the orrery, a mechanical model of our solar system that shows the relative position and motion of the planets, moon, and sun as they orbit.

(Image below) Almanacs were vital for farmers planning their agricultural work for the year. Such information was scrupulously calculated using a tool called the astrolabe to observe and predict the position and movement of the sun and stars.

The exhibition is open through June 8, 2025 at the Milberg Gallery in Firestone Library. Please visit the website to view the gallery’s opening hours and for information about public tours and how to visit.