SCHOTT, GASPAR. 1608-1666.
Schola steganographica, in classes octo distributa. Nuremberg: Jobus Hertz, 1680.
4to (210 x 160 mm). -44 52 A-2X4 2Y2. Additional engraved title, 11 folding engraved plates and letterpress tables. Early 18th century half vellum. A few wormtrails, light browning, occasional soiling, binding heavily rubbed, bookplate.
Second edition. Scientific compendium of cryptography, secret writing and also "magnetic secret signals."