Fifty-two discoveries from the BiblioPhilly project, No. 14/52
A volume with a rust stain from eyeglasses, presented with an actual pair of eyeglasses in front of it (exhibited in Le verre, un moyen-âge inventif, Musée National du Moyen-Âge-Thermes de Cluny, 20 September 2019 – 8 January 2018); Book of Hours for the Use of Rome, Philadelphia, Philadelphia Museum of Art, 1945‑65‑14, fols. 106v–107r (eyeglass imprints in the gutter)
The recent exhibition on glass in the Middle Ages (Le verre, un moyen-âge inventif, at the Musée National du Moyen-Âge-Thermes de Cluny) exhibited a famous rust-stain in an incunable caused by a pair of eyeglasses long forgotten inside the closed book. The differential condensation of the metal frames around the lenses caused traces of oxidation to transfer to the paper surface over time. Presented evocatively in front of the book in the exhibition was an actual pair of late-medieval eyeglasses, excavated archeologically in a different context. Unsurprisingly, the original pair of eyeglasses responsible for the stain is long gone. And, in any case, since the incunable is a rather dry theological volume with few annotations, and the eyeglasses were left in for years, or possibly even decades or centuries, this is clearly the product of one-time forgetfulness. After all, how many items have we forgotten in our own books over the years?