A scrap piece of paper was inserted over pp. 3-4 of Agostino Gerli's Opuscoli (Russell's Library, no. 32). Because it is on ballooning, the book probably belonged to Ludwig Wittgenstein but does not bear his signature. The scrap appears to have come from an Italian ledger book. The number 3098 has been written perpendicular to the original text, possibly as a call number.