Alexander Calder, Four Planes Escarpé (left), and Six Planes Escarpé (right), 1967; installation view near Gstaad; sheet metal, bolts, and paint; 120 x 139 x 147 inches and 119 x 156 x 150 inches; photo by Jon Etter, © 2016 Calder Foundation, New York / DACS, London, courtesy of Calder Foundation, New York / Art Resource, New York and Hauser & Wirth