Best known for his invention of the mobile sculpture, Alexander Calder (b. 1898, Pennsylvania; d. 1976, New York) approached art as the "disparity that exists between form, masses, and movement." Calder studied drawing and painting under George Luks and Boardman Robinson at the Art Students League in New York, before moving to Paris in 1926, where he was introduced to European avant-garde art circles. Calder created mobiles that moved with air currents, or human interaction. His wide-ranging practice included paintings, stabiles, standing mobiles, monumental outdoor sculptures, works on paper, domestic objects, and jewelry. Today, his works are held in the collections of such major museums as The Museum of Modern Art in New York, the National Gallery of Art in Washington, D.C., the Whitney Museum of American Art, New York, the Art Institute of Chicago, and the Tate Gallery in London.