Trained as an engineer, American sculptor Alexander Calder won acclaim from the art world for his mechanical sculptures and fanciful mobiles. In a piece published in ARTnews in 1947, philosopher Jean-Paul Sartre recalled with admiration and amusement how he had nearly been hit in the face by a lazily turning mobile in Calder's Paris studio. Sartre argued that such unpredictability of movement, dependent entirely upon wind power, embodied the essence of natural movement.
    French filmmaker Agnes Varda, a friend of Calder's, snapped this picture of the sculptor moving a mobile across a Paris street.

Agnes Varda (born 1928)
Gelatin silver print, 1955
Published November 1977
ARTnews Collection, New York City