[PEPPER'S GHOST] Eleven Patents for Pepper's Ghost Improvements and Related Optical Effects. American, 1900s ? 20s. Group of illustrated patents for ?optical illusions" and ?theatrical effects" ranging from an appearing and vanishing canary in a cage, to a modified version of the Girl in Fishbowl, a method of displaying merchandise on a mirror via the Pepper's Ghost principle (via an ?invisible operator"), goldfish appearing in empty bowls, a peep show design, and more. Illustrated with technical drawings, bound with staples as issued by the U.S. Patent Office. A fascinating trove of documents related to this famous ghost illusion and related principles.