The forecast this week in London is scorchio!—with the mercury due to spike at around 30 degrees. Tate Britain’s open-air café on the front lawn is a popular sun trap and watering hole. On the parched grass can be found a bronze by Barbara Hepworth in splendid isolation. Figure for Landscape, 1959-60, usually resides in a shady spot in the artist's garden in Cornwall, now the Barbara Hepworth Museum, St Ives. But it has come up to town this summer to play a part in Sculpture for a Modern World (until 25 October). Some critics have carped that the Hepworth exhibition in Tate Britain’s Linbury Galleries, which are on a lower level of the building, lacks natural lighting. Another gripe is that most of the works are somewhat small scale. The criticisms are not without foundation but do not tell the full story of the show. It’s hard to miss the monumental bronze at the entrance of the show. Happily Hepworth’s Square with Two Circles, 1963, is bathed in natural light too, this time diffused via a skylight aloft.