THE HEAD OF JOHN THE BAPTIST.
Before a concave mirror, which the spectator sees, have a little railway with a head on a dish, in wax or plaster, strongly illuminated, and concealed from him. Let a wire in the hands of an assistant, or wound on a drum by the release of a detaining spring, draw this head on its carriage into the focus of the mirror, when it will seem to start out and fly towards the beholder.