The Keynes Bequest is not merely a collection of books. Interspersed among first editions of Galileo, Descartes, Pascal, Hobbes, Kant and Locke are a number of pamphlets of historical, literary and scientific significance, ranging in size from one sheet to several pages. In the extensive collection of first and early editions of Isaac Newton’s works is an anonymous pamphlet with the caption “29. Julii 1713”. This is the so-called Charta volans (flying sheet), an important document written by Gottfried Leibniz during the bitter controversy between him and Newton over which of them invented the mathematical study of change, calculus. Given the rarity of this pamphlet (the only other copies are in Yale, Chicago and in the Burndy Library), and in the interest of scholarship, we provide a scan of all four pages:
Its acquisition history is also rather fascinating. Keynes had originally bought two copies of the pamphlet, and observed in a letter to K. G. Maggs when the latter offered to purchase the duplicate copy in May 1942 that he had done so “not because I wanted them, but because they were fastened together, never having been separated by a paper knife when issued. So far I have not had the heart to split the Siamese twins.” The correspondence between Keynes and Maggs throws an interesting light on his relationship with booksellers and how he went about augmenting his collection of rare books and pamphlets:
The “American library which specialises in Newton material” that bought the second copy of the Charta volans is almost certainly the Burndy Library, founded the previous year by the industrialist and historian Bern Dibner. Their copy is now at the Huntington Library in San Marino, California.
As the above correspondence reveals, the loss of one of the “Siamese twins” to the Burndy Library led to Keynes’s acquisition of another exciting “flying sheet”, namely a leaf from the Gutenberg Bible, the first book printed using movable type which marked the beginning of the Printing Revolution. The iconic 42-line Bible was printed in Mainz, ca. 1454-55, by Johannes Gutenberg. Of the about 180 copies printed, 49 are known to have survived, only 21 of which are complete. This leaf includes all of Jeremiah XX and part of Jeremiah XXI:
The addition of a leaf from the Gutenberg Bible to Keynes’s collection means that the items in the Keynes Bequest cover five centuries of printing, from its very inception in the middle of the fifteenth century, right up to the middle of the twentieth.