The Art of the Diddle: Secret Writing
Clarence S. Brigham, in Edgar Allan Poe’s Contributions to Alexander’s Weekly Messenger, writes:
Henry B. Hirst, in his biography of Poe, in the Philadelphia Saturday Museum, of March 4, 1843, enlarges at length on Poe’s analytical mind and his ability in solving ciphers. In the same paper Thomas C. Clarke refers editorially to Poe’s perceptive mind and says that Poe, when in his company, solved immediately a difficult cipher which had been printed in the Baltimore Sun, and which he reprints, with the solution.1