Measured elevation of a window from the courtyard and profiles of mouldings by leading architect and designer Sir William Chambers (1723-1796). The drawing shows a pedimented window designed by Antonio da Sangallo, the younger. The pediment is supported on small scrolling brackets. On the left-hand edge of the sheet are profiles of the mouldings at the sill and top of the window. The left-hand edge of the sheet has been trimmed and a small rectangle of paper cut from the top left corner. On the verso, an unfinished drawing of another window, of a type shown on the ground floor of the Palazzo Chigi-Odescalchi (cf. cat.544).

Chambers moved to London in 1755 and published his influential Treatise on Civil Architecture in 1759. Chambers demonstrated the breadth of his style in buildings such as Gower (later Carrington) House and Melbourne House, London, in such country houses as Duddingston, Scotland, and in the garden architecture he designed for Wilton House, Wiltshire, and at Kew Gardens. He became head of government building in 1782, and in this capacity built Somerset House, London.