J.M.W. Turner: Sketchbooks, Drawings and Watercolours

ISBN 978-1-84976-386-8

Joseph Mallord William Turner Lecture Diagram 20: Conic Sections (after Thomas Malton Senior) c.1810

Joseph Mallord William Turner 1775–1851
Lecture Diagram 20: Conic Sections (after Thomas Malton Senior) circa 1810
D17033
Turner Bequest CXCV 63
Pencil and watercolour on white wove paper, 674 x 1000 mm
Watermarked ‘J WHATMAN | 1808’
Inscribed by Turner in red watercolour ‘20’ top left
Inscribed by John Ruskin in red ink ‘63’ bottom right
 
Accepted by the nation as part of the Turner Bequest 1856
In a section on curvilinear perspective in Lecture 2, given as Professor of Perspective at the Royal Academy, Turner addressed the role of conic sections,1 presenting Diagram 20 to illustrate how the theory of these enters into the perspective representation of circles.2 It incorporates elements from several illustrations found in A Compleat Treatise on Perspective in Theory and Practice on the True Principles of Dr Brook Taylor (1775) by the elder Thomas Malton (1726–1801); see pl.VII, figs.29 and 30. Together with the right-hand portion of Diagram 19 (Tate D17032; Turner Bequest CXCV 62), the drawing shows ‘some of the arrangements that can arise when the circle is not on the axis of the eye. In these cases the cone is skewed, or “scalene”’.3 Turner also sketched the diagram in his lecture notes.4
1
Turner, ‘Royal Academy Lectures’, circa 1807–38, Department of Western Manuscripts, British Library, London, ADD MS 46151 BL MS L folio 9 and verso. For earlier versions of related lecture material, see D folio 5 and E folio 10 verso.
2
Turner, ‘Royal Academy Lectures’, circa 1807–38, Department of Western Manuscripts, British Library, London, ADD MS 46151 BL MS L folio 9 verso. For earlier versions of related lecture material, see E folio 10 verso.
3
Davies 1994, p.164.
4
Turner, ‘Royal Academy Lectures’, circa 1807–38, Department of Western Manuscripts, British Library, London, ADD MS 46151 BL MS L folio 9 verso.
Technical notes:
Peter Bower states that the sheet is Double Elephant size Whatman paper made by William Balston, at Springfield Mill, Maidstone, Kent. The largest group within the perspective drawings, this batch of paper shows a ‘grid-like series of shadows that can be seen within the sheet in transmitted light. This appears to have been caused by a trial method of supporting the woven wire mould cover on the mould’. Because this is the only batch he has seen with such a feature, Bower believes that ‘it may have been tried on one pair of moulds and for some reason never tried again’. He also writes that it is ‘not the best Whatman paper by any means; the weight of this group is also very variable and the moulds have not been kept clean during use’1
1
Notes in Tate catalogue files.
Verso:
Blank, save for an inscription by an unknown hand in pencil ‘65’ bottom left.

Andrea Fredericksen
June 2004

Supported by The Samuel H. Kress Foundation

Revised by David Blayney Brown
January 2012

How to cite

Andrea Fredericksen, ‘Lecture Diagram 20: Conic Sections (after Thomas Malton Senior) c.1810 by Joseph Mallord William Turner’, catalogue entry, June 2004, revised by David Blayney Brown, January 2012, in David Blayney Brown (ed.), J.M.W. Turner: Sketchbooks, Drawings and Watercolours, Tate Research Publication, December 2012, https://www.tate.org.uk/art/research-publications/jmw-turner/joseph-mallord-william-turner-lecture-diagram-20-conic-sections-after-thomas-malton-senior-r1136484, accessed 20 January 2020.