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Turner concluded Lecture 2 as Professor of Perspective at the Royal Academy with this view of the upper part of the Great Room at Somerset House, the hall where he taught his course. Somerset House, on London’s Strand, was designed by William Chambers and was the home of the Royal Academy. The Great Room was used for the summer exhibition and for seasonal lectures by the professors. For improvements to the room for teaching, planned jointly by Turner and his friend John Soane, Professor of Architecture, see Introduction. There is a sketch of the room’s upper cornice in Turner’s lecture notes.1 Now part of the Courtauld Gallery, the room is little changed today.
Turner uses Diagram 26 to point out the ways in which standard perspective does not represent lateral convergence on the picture surface. Maurice Davies writes that ‘the far wall is parallel to the picture plane and so, following the principles of standard perspective, its main horizontal architectural elements are represented by lines that are parallel to each other and to the horizon. They do not converge on the picture surface. But Turner argued that the picture is wrong’.2 Turner may have pointed to the actual ceiling as he spoke as follows:
no line is parallel in nature but the horizontal. The upper cornice to all those seated in the centre appears to dip each way and the underneath part or lines appear to approach each way from the eye looking at them from the centre and the three squares tho [sic] of equal measures seem of different proportions but no parallel principle can make them so for they would increase by as much as the sides of each are seen by the rules of parallel perspective whereas the eye must take in all objects upon a curve. The eye can only but receive what is within its limits of extended sight which must form an entire circle therefore it must always view but a part of a circle at a time the objects should be thrown on a part of a circle instead of a square and as every line is more or less elevated so it must partake of a parabolic curve because the eye is within the area of its circle which is the case in nature in panorama and panoramic views and they are produced by such means.3
Turner, ‘Royal Academy Lectures’, circa 1807–38, Department of Western Manuscripts, British Library, London, ADD MS 46151 L folio 16.
Davies 1992, p.75.
Turner, ‘Royal Academy Lectures’, circa 1807–38, Department of Western Manuscripts, British Librarso–16. For earlier versions of the lecture, see D folio 8 verso and E folio 18.