Calder’s father and grandfather were both noted sculptors, and his mother was a painter. As a child, Calder also showed some talent as an artist. However, he earned a degree in mechanical engineering in 1919, and spent several years in different jobs before studying painting at the Art Students League in New York in 1923.

He worked as an illustrator in New York, continued to paint, and began to sculpt in sheet metal and wire before setting off to Paris in 1926. It was here that he brought his wire sculptures to maturity, shaping forms or figures using pliers or his bare hands. At a time when sculptures were still usually made from stone, bronze or wood, Calder’s use of a commonplace industrial material was seen as radically new. His approach seems especially striking when applied to a heroic subject like Hercules and Lion, which viewers might expect to be mounted sturdily on a plinth rather than hanging suspended in the air. Calder’s was a sculpture of line rather than mass, which critics defined as ‘drawing in space’. He felt that it was a mark of modernity that his wire figures possessed a kind of transparency, allowing other objects to be visible through them.

Goldfish Bowl was a gift for his mother, and represents an early attempt at the problem that preoccupied Calder throughout the 1920s and 1930s – how to incorporate actual movement into sculpture. The goldfish are set in motion by turning a crank at the bottom of the sculpture. As this ingenious device indicates, Calder’s mechanical insight provided an important resource for his mature work.