In Lecture 2 as Professor of Perspective at the Royal Academy, Turner spent some time discussing conic sections (see Diagrams 19 and 20, D17032, D17033; Turner Bequest CXCV 62, 63), turning at one point to the elder Thomas Malton’s explanation of the rare circumstances in which the parabola and hyperbola can arise.1 The three diagrams (see also another numbered 22, and 23, D17036 and D17037; Turner Bequest CXCV 66, 67) made to accompany this part of the lecture show the geometry of the parabola and are based on illustrations from John Hamilton, Stereography; or a Complete Body of Perspective in all its Branches (1738, fig.84, no.1). According to Davies, the diagrams have ‘little relevance to the discussion and Turner may have chosen to include them merely because Malton mentions works on conic sections by [Hamilton] at this point’.2 See Turner’s Perspective Sketchbook (Tate D07384–D07386; Turner Bequest CVIII folios 17 verso–18 verso) for preliminary sketches and notes.
Thomas Malton [Senior], A Compleat Treatise on Perspective in Theory and Practice on the True Principles of Dr Brook Taylor (1775); Turner, ‘Royal Academy Lectures’, circa 1807–38, Department of Western Manuscripts, British Library, London, ADD MS 46151 L folio 9 verso. For earlier versions of related material, see D folio 5 verso and E folios18 verso–19.
Davies 1994, p.165.
Peter Bower states that the sheet is Super Royal size Whatman paper made by William Balston and Finch and Thomas Robert Hollingworth, at Turkey Mill, Maidstone, Kent. He writes that all ‘the sheets in this batch have some streaking across the sheet, probably from a fault in the sizing’.1
Notes in Tate catalogue files.
Blank, save for an inscription by an unknown hand in pencil ‘67’ top left.
Supported by The Samuel H. Kress Foundation