Hard Cover. New York: Albert & Charles Boni, 1930. Very Good.
First edition, second printing. Presentation copy; signed and inscribed by Albert Einstein in full to the front endpaper: "For Mrs. Kahn/ Albert Einstein/ Pasadena 1931." Original publisher's red cloth, front board lettered in black and ruled in gilt, spine lettered in gilt and black. About very good copy; spine faded, upper spine worn and lightly frayed, some scattered spots and small stains to covers. Housed in a custom leather clamshell box.