Brussels: Fr. Gobbaerts, 1880. In seven volumes. Inscribed twice by Chalon to Belgian-French astronomer and mathematician, Adolphe Quetelet (1796-1874). 8vo. With half-titles. Full olive green morocco, stamped in gilt, sunning to spines, rubbing; top edges gilt; spotting and minor soiling throughout.

These seven volumes comprise over 200 pamphlets, notices, and reports related to the infamous Fortsas Hoax, including the second edition of the original Fortsas catalogue, "completed after [Chalon's] death by his heirs, who added to the collection obituaries relating to Chalon" (De Callataÿ & Sorgeloos, p. 94).

The Fortsas Hoax refers to a prank executed by Rene Chalon in 1840 which saw numerous booksellers, librarians, and rare book collectors throughout Europe receiving an auction catalogue advertising the book collection of "Jean Nepomucene Auguste Pichauld, Comte de Fortsas." According to the catalogue, Fortsas had collected books of which only one copy was known to exist, making his collection one of the most unique in the whole of Europe.

On August 10, 1840 collectors from across the continent arrived in Binche, Belgium, to bid on the books, only to discover that the offices at which the auction was to take place did not exist. Notices had been put up throughout the town informing potential bidders that the sale had been cancelled and the books donated to the local public library. Disappointed buyers hoping to view the collection were further annoyed to find that the town of Binche did not, in fact, have a public library. It was later revealed that this had been an elaborate prank perpetrated by Renier Hubert Ghislain Chalon, a retired military officer who enjoyed playing practical jokes on the upper classes.