This black and white photograph shows an original design drawing for the interior of Wesley's Chapel (1778).
The building was designed by George Dance the Younger (1741-1825) who, at the time, was the Architect and Surveyor to the Corporation of London and responsible for the design of public buildings in the City of London. It was the same office Christopher Wren had held a hundred years or so before Dance, during which time Wren designed the City Churches.
The design drawing shows elaborate, classical windows and neoclassical friezes, echoing those designed for the outside of the Chapel. These were not carried out, so the Chapel, in Wesley's words, became 'neat but not fine'.
The original drawing is in the Guildhall Library, London. See also the other photographs of Dance's designs for the Chapel in the Online Collection, 2008/11488/4-5.