These beautiful engravings were photographed for a #libraryexhibit here at the #kislakcenter in 2003. Hailing from the Charles J. Mendelsohn Cryptology Collection, they were included in “Deciphering the Past: A Retrospective View of the Art & Science of Cryptology, curated by our Director of Special Collections Processing, Regan Kladstrup. Here we have an example (exemplum) and key (clavis) that could be used in the service of sending a top secret message, what fun! *** Cryptographica, Germany, 1684 652M F913 http://ow.ly/rQQB30hcQwI Charles J. Mendelsohn Cryptology Collection *** #pennlibraries #inthestacks #cryptology #flowers #etching #fineprinting #rarebooks #scpc