Bradley, IL: Lindsay Publications Inc., 1986. Staple-bound Softcover. Very Good. Item #044851
Originally entitled "Dieterich's 50 Perpetual Motions" and last copyrighted in 1919 by the author. The pages are crisp and clean, with no owners' marks; the stapled binding is secure; the cover has only gentle age-toning at the edges and is otherwise excellent.