In 1840, a curious sales catalog titled "Catalogue d'une tres-riche mais peu nombreuse collection de livres provenant de la bibliotheque de fen M. le Comte J. N. A. de Fortsas." (Catalogue of a very rich but very small collection of books coming from the library of Monsieur Count J. N. A. Fortsas) appeared in Europe. The catalog was indeed small, listing only 52 books, and yet it caused great excitement in the book collecting world. The Count de Fortsas' collection was, literally, unique: the Count collected books of which only one copy existed. And now all of these singular volumes were for sale.
Reaction to the Count's catalog was passionate. Scholars were dismayed to find books that predated their own studies. Bibliographers were excited to find new and previously unknown sources. Some collectors claimed that the Count's claims were exaggerated, since they owned copies of books listed. The Princess de Ligne wished to buy "Mes Campagnes" to shield the family honor (she wrote to her agent "Buy, I conjure you, at any price, the follies of our rascally grandfather."). The keeper of the Royal Library at Brussels was anxious to keep the collection in Belgium. Many people simply wanted to meet the eccentric Count. Bids poured in from across the continent.
The sale of the books was to take place on August 10th, 1840, in the Belgian town of Binche. Collectors and booksellers from all over Europe flocked to Binche with the expectation of competing for the rare books. On the day of the sale, the buyers were informed that the sale was cancelled, and that the Count had donated his collection to the local library. Eagerly, the buyers searched for the library, to look at the treasures. They were disappointed. Binche had no public library.
The Count de Fortsas and his collection was a hoax created by Renier-Hubert-Ghislain Chalon, a retired major, numismatist, and practical joker. Along with some confederates, he carefully crafted a list of books that would include entries of specific interest for every leading book dealer of the time. The catalog was created as a joke, merely to tweak the experts, and no one involved lost more than traveling expenses to Binche. Chalon's catalog was the largest, and best, bibliohoax of all time.
Sources:
The Fortsas Hoax by William Blades, edited by James Moran, Aborfield Products Ltd., London, 1961. 33 pages. Includes a reprint of the Fortsas Catalogue, essays.
The Fortsas Bibliohoax by Walter Klinefelter, Carteret Book Club, New Jersey, 1941. 72 pages. Includes a reprint of the Fortsas Catalogue, essays, bibliography