New York: George Wittenborn, Inc., 1965, 1966. Two vols., square 12mos; 84, 82pp; printed wrappers. A slight wrinkle to one corner of the first volume; wrappers lightly rubbed; a nice set. Item #206091
Although published as companion volumes, the two books are not identical in format, with The Discovery of the Circle just slightly larger in size by about a millimeter in both height and width. The translations are by Desmond O'Grady and Marcello & Edna Maestro respectively.