This effect appeared as “Gravity Defied” in August Roterberg's New Era Card Tricks, 1897, p. 97.

Postdating methods with pins, Burling Hull invented the method in which a half-circle tab concealed in the back design of a prepared card is used to suspend a circle of loose cards under the palm-down hand. He published this in Sleights, 1914, p. 7, where he says he “invented and Copyrighted” the gimmick in 1907.