Alexander Calder Mobile January 25, 2010

The work sculptor Alexander Calder created for the East Building, 'Untitled, 1976,' is by far the largest example of what is called "motorless construction." The 76-foot-long mobile is constructed of aluminum honeycomb panels, hollow aluminum tubes, and very little steel. Calder's last major work of art, it was installed on November 18, 1977, one year after his death.