Museum of Contemporary Art Chicago

Alexander Calder (American, 1898–1976)

Four Boomerangs, 1949

Painted sheet metal and steel wire

39 x 63 in. diameter (99.1 x 160 cm diameter)

Collection Museum of Contemporary Art, Chicago, gift of Ruth Horwich

Trained as an engineer, Alexander Calder applied his knowledge of mechanics to colorful abstract shapes. Activated by air currents, his whimsical mobiles are ever-changing compositions. Marcel Duchamp invented the word mobile to describe Calder’s revolutionary work. Even Calder’s Flamingo (1973)—located in Chicago’s Loop—and his other static sculptures, dubbed stabiles by Jean Arp, evoke movement as they invite viewers to contemplate them from every angle.