The Transfiguration by Raphael (Pinacoteca Vaticana, Rome) was seen by Turner in the Louvre, Paris, in 1802; a probable colour key of it is in his Studies in the Louvre sketchbook (Tate D04287; Turner Bequest LXXII 13). This diagrammatic treatment must have been based on engraved sources as no other drawing by Turner made directly from the picture is known.
At the conclusion of the version of Lecture 1 delivered on 7 January 1811, as Professor of Perspective at the Royal Academy, Turner returns to the role of geometry in the history of painting.1 His diagram of The Transfiguration demonstrates how the upper part of the composition is made up of intersecting triangles, forming a pyramid, and shows how the figure of Christ is larger than the others because it is nearer to the viewer. Turner claims that it would be presumptuous on his part to say whether Raphael ‘had any allegorical intention in placing the three figures at the top of the picture,’ only that it was clear from the design the extent to which he followed geometric rules. As he puts it, ‘the higher the authority the stronger may it be affirmed that lines cooperate and that chance could not have produced the positive geometric figure in the “Transfiguration” which is now placed before us’. There are three sketches related to this diagram in the preliminary draft of the lecture.2 Turner’s varied critiques and treatments of the Transfiguration in other lecture material are noted by Barry Venning.3
For another diagram numbered ‘10’, of an architectural elevation, see Tate D17144; Turner Bequest CXCV 173. That the present one was used in 1811 is confirmed by press reports. On 8 January The Sun recorded Turner showing ‘a print of Raphael’s “Transfiguration”’ together with his ‘geometrical diagram on the subject’4 and The Examiner described how he ‘inculcated the advantage of geometry in painting from the practice of Raphael, especially in his celebrated work of the Transfiguration, in which the figures of Christ and others are geometrical agreeably to the recommendation of Michael Angelo to make the figure three by two’.5
Turner, ‘Royal Academy Lectures’, circa 1807–38, Department of Western Manuscripts, British Library, London, ADD MS 46151 K folio 19 verso.
Turner, ‘Royal Academy Lectures’, circa 1807–38, Department of Western Manuscripts, British Library, London, ADD MS 46151 C folio 12 verso.
Venning 1983, p.49 note 68.
Cited by Davies 1992, p.105 note 49.
Cited by Egerton [and Ellis] 1980, [p.5].