Degas' designs on beauty

'Nothing in art is accidental,' declared Degas, an artist who exhibited regularly with the Impressionists but who eschewed their spontaneity and pursued the architectural delineation of line as well as the atmospheric effects of evaporating colour and light.

This small exhibition examines 12 paintings to illustrate just how much planning went into even the sketchiest of works. Each is selected from a specific phase in Degas's life, from early portraits and history paintings, to his extraordinarily intimate paintings of ballet dancers, circus performers and bathing women.

By using infrared photographs and X-rays and showing these and the finished works alongside preliminary drawings and paintings, we learn something of the ingenuity of his methods.

One of Degas's key paintings from the early 1860s is Young Spartans Exercising, a rather strange and somewhat stilted painting depicting naked Spartan boys and girls confronting each other across opposite ends of the canvas and limbering up for apparent combat.

Sketches show the subtle but significant stages of its evolution, together with an unfinished painting from the Art Institute Of Chicago, shown alongside the finished work for the first time.

Meanwhile, a rather haunting portrait of Princess Pauline de Metternich, from 1865, shows what must be one of the first paintings openly acknowledged as a copy of a photograph. Here, the blurring of facial features imitates a long exposure; while later works include Combing The Hair, 1896, a glorious and audacious study in fiery reds.

Until Jan 30, National Gallery, Trafalgar Square WC2, daily 10am to 6pm (Wed to 9pm), free. Tel: 020 7747 2885. www.nationalgallery.org.uk Tube: Leicester Square/Charing Cross