Revolving Torsion (1972-3) is a late work by the Russian sculptor Naum Gabo, who died in 1977.
Born Naum Pevsner in Russia, he changed his name when he took up sculpture to avoid confusion with his elder brother Antoine who was a painter. He was a truly international modernist, fluent in several languages, studying medicine, science and engineering in Munich before becoming a full-time artist and working in Paris, Copenhagen and Oslo. At the outbreak of the Russian Revolution he returned to Moscow where he pioneered the Constructivist movement, even coining the name.
Later he moved to Germany to teach at the Bauhaus, developing the theory of Kinetic Art that aims to exploit motion or the illusion of motion for its impact.
As a Jew, the rise of the Nazis forced him to move first to Paris and then to London. In 1946 he went to America.
Revolving Torsion certainly has a lot of movement in it, looking like a part of some turbine that interacts with the multiple jets of the fountain. Creating the sweeping stainless steel blades must have drawn considerably on the engineering skills he had picked up all those years before.
Unfortunately it is rather upstaged by the building behind.