A rare manuscript written by a leading astronomer in Rome at the height of Galileo’s astronomical discoveries recently was acquired by the University of Oklahoma’s History of Science Collections.

The newly acquired manuscript, Tractatus de sphaera, by Oratio Grassi records Grassi’s lectures in mathematics and astronomy. The Grassi manuscript is one of three works by Grassi to enhance OU’s Galileo collection this year. In two just-acquired printed books, Grassi discussed three comets that appeared in the sky in 1618.

“The Grassi manuscript is an important addition to the OU History of Science Collection, which is already recognized as among the small number of great collections in science in the world,” said OU President David L. Boren.

The Grassi manuscript is one of only a few astronomical manuscripts from the leading Jesuit university preceding the publication and subsequent condemnation of Galileo’s Dialogo (1632). OU holds Galileo’s own copy of the Dialogo, containing his handwritten comments in the margins.

“By any measure, this Grassi manuscript is a significant acquisition for the University of Oklahoma and an important addition to the prestigious Galileo works held by our History of Science Collections,” said Rick Luce, dean of University Libraries. “The penmanship is beautiful,” said Luce, noting that some of the pages have detailed illustrations, all hand-drawn.

The Grassi manuscript discusses Gaileo’s discoveries, including imperfections on the surface of the Sun and Moon and the satellites of Jupiter. These discoveries were first published by Galileo in Sidereus nuncius, printed in Venice in 1610. The OU copy of Sidereus nuncius displays Galileo’s signature on the title page.

“The OU Galileo collection is remarkable,” Luce said. “While many major libraries hold one or two first editions of Galileo, OU holds the entire set of 12 first editions. Neither the Library of Congress nor the British Library can say the same. Moreover, four of OU’s first editions, including the Sidereus nuncius and the Dialogo, contain Galileo’s handwriting. The Grassi manuscript and the two other Grassi books are unique additions to an already world-class Galileo collection.”

The acquisition was made possible with a $500,000 gift from the OU Athletics Department to establish an endowment to support exhibits and acquire rare works for the History of Science Collections.

“We are grateful to the Athletics Department for funding the endowment that made it possible for this manuscript to find its way to OU for its permanent home,” Luce said.

Key works from the OU Galileo collection, including the newly acquired Grassi manuscript, are now on display in the History of Science Collections on the fifth floor of Bizzell Memorial Library.