The sculpture is based on a piece of flint with three prongs.[2]
Moore intended to create a sculpture that could be placed in a variety of different orientations, and which would still work when viewed from different angles. The title refers to the points of the flint, and the intention that the sculpture would be effective in three orientations.
Moore first created a plaster maquette (LH 531) in 1964. Moore scaled the maquette up into a larger plaster version, now held by the Art Gallery of Ontario but damaged beyond repair in 1974, which was cast as a 30 inches (760 mm) bronze working model (LH 532) in an edition of seven (plus one artists model) in 1964. One example is held by the Tate Gallery in London. This model was scaled up to the full-size sculpture (LH 533), cast in an edition of three. The full-size bronze was too large and heavy to be moved into different positions by one person.[3]
The example at Columbia University has a granite base which measures approximately 2 feet, 8 inches and has a diameter of 7 feet, 7 inches.[10] It was dedicated on October 3, 1973. It was surveyed and deemed "treatment needed" by Smithsonian Institution's "Save Outdoor Sculpture!" program in February 1993.[10]