To me the most important thing in composition is disparity. Thus black and white are the strong colors, with a spot of red to mark the other corner o… - Alexander Calder

Question: Which has influenced you more, nature or modern machinery?
I haven't really touched machinery except for a few elementary mechanisms like levers and balances. You see nature and then you try to emulate it. But, of course, when I met Mondrian [Paris, 1930] I went home and tried to paint [for a while]. The basis of everything for me is the universe. The simplest forms in the universe are the sphere and the circle. I represent them by disks and then I vary them. My whole theory about art is the disparity that exists between form, masses and movement. Even my triangles are spheres, but they are spheres of a different shape.

Marcel Duchamp's 'Nude descending the stairs' is the result of the desire for motion. Here he has also eliminated representative form. This avoids the connotation of ideas which would interfere with the success of the main issue - the sense of movement.

Question: Do you make preliminary sketches?
I've made so many mobiles that I pretty well know what I want to do, at least where the smaller ones are concerned. But when I'm seeking a new form, then I draw and make little models out of sheet metal. Actually the one at Idlewild [Airport (in the International Arrival Building)] is forty-five feet long and was made from a model only seventeen inches long. For the very big ones I don't have machinery large enough, so I go to a shop and become the workman's helper.