The sculpture is a largely flat, irregular shape, broadly oval, pierced near the top by a circular hole. The flat surfaces are pitted and scored with three intersecting lines – one broadly vertical, and two broadly horizontal – on each face, reflecting its casting in separate pieces. In 1970, the art criticEdwin Mullins suggested: "it is a torso, it is a profile with an eye, it is an expanse of space in which the sun rises, it is a blade, it is a human hand... raised flat in a sign of authority, or of salute, or as a gesture of allegiance". In 1974 the art critic Dore Ashton suggested it is a "vision of the cosmos".
Background
The work was commissioned by the Jacob and Hilda Blaustein Foundation as a memorial to the UN Secretary GeneralDag Hammarskjöld after his death in an air crash in Africa in 1961. Jacob Blaustein had served as the United States delegate to the United Nations. Hammarskjöld was a collector of Hepworth's works, including her 1937–38 sandalwood sculpture Single Form which he displayed in his United Nations office. He had discussed with Hepworth the possibility of her being commissioned for a work at the United Nations Headquarters. She may have started work, expecting a commission, before Hammarskjöld's death: the commission was formally ratified by the United Nations in September 1962.
Sculpture
Hepworth had started work that led to the bronze in 1961. Single Form was cast in bronze in an edition of seven in 1961, with its shape marked with an inscribed circle. Her similar wood sculpture from 1961, Single Form , in figured walnut, has a circular depression on one face near the top. It is owned by the Tate Gallery and displayed at the Barbara Hepworth Museum in St Ives, Cornwall. Hepworth was working on the walnut sculpture when she received news of Hammarskjöld's death in September 1961, and named it after that month. Another related work is Hepworth's 1961 bronze Curved Form : a similar shape, pierced with a hole, with copper strings; an example was sold at auction at Christie's in 2013. She moved the depression, which became a hole, in the larger high Single Form bronze from 1961. Single Form and a plaster model of Single Form were included in the Hepworth exhibition at the Whitechapel Art Gallery in May–June 1962. The first completed bronze of Single Form was included in the open air sculpture exhibition at Battersea Park in 1963. This first cast was shipped to the US in October 1963 and retained by the Blaustein family until 2005, when it was donated to Johns Hopkins University and displayed at the Paul H. Nitze School of Advanced International Studies in Washington, D.C.. A second cast was made in 1963, bought by London County Council for 6,000 guineas and installed at Battersea Park in 1964, where it remains on the south shore of the lake. It measures . Hepworth doubled the size of Single Form to create a full-size armature at the Palais de Danse annex to her studio in St Ives in early 1963, in wood covered with plaster. The full-size sculpture was cast in seven pieces and assembled at the Morris Singer foundry in London, the lines on the surface reflecting its casting. It measures high and weighs. It was erected in New York in May 1964, standing on a granite plinth near the edge of a circular pool of water, about in diameter, with a fountain, which had been built with a $50,000 gift from the children of the United States, Puerto Rico and the US Virgin Islands; it was unveiled on 11 June 1964.
