By the time the gallery had been rehoused in a new building, designed by William Wilkins and erected in Trafalgar Square (on the former site of the King's Mews), and opened in 1838, Sir Robert Peel was propounding the idea of a National Gallery as a social force, a bond between rich and poor, as well as a stimulus for the improvement of industrial design. By 1843 the National Gallery collection had grown from 38 to 194 pictures. Only the façade onto Trafalgar Square remains essentially unchanged from this time, as the building has been expanded piecemeal throughout its history. The building often came under fire for its perceived aesthetic deficiencies and lack of space; the latter problem led to the establishment of the Tate Gallery for British art in 1897. Recent developments include the new Sainsbury wing, designed by Robert Venturi and Denise Scott Brown, and opened in 1992. Today the collection numbers over 2,300 paintings.