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

ISBN 978-1-84976-386-8
J.M.W. Turner > 1802-18 Academician and professor > Perspective lectures c.1809-28 > II. Various Perspective Diagrams > Artwork

Joseph Mallord William Turner Lecture Diagram: Perspective Representation of a Triangle c.1810-28

Joseph Mallord William Turner, ‘Lecture Diagram: Perspective Representation of a Triangle’ c.1810-28
Joseph Mallord William Turner 1775–1851
Lecture Diagram: Perspective Representation of a Triangle circa 1810–28
D17020
Turner Bequest CXCV 50
Pencil, ink and watercolour on white wove paper 487 x 601 mm
Inscribed by John Ruskin in red ink ‘50’ top left
 
Accepted by the nation as part of the Turner Bequest 1856
Made in connection with Turner’s lectures as Professor of Perspective at the Royal Academy, this diagram is based on a figure from A Compleat Treatise on Perspective in Theory and Practice on the True Principles of Dr Brook Taylor (1775, pl.XI, fig.56) by the elder Thomas Malton (1726–1802). Malton used it to illustrate Problem XVIII: ‘How to find the perspective representation of a triangle, having the original line given, in any plane, whose intersection and vanishing line is also given, and the place of the eye’.1 1 Not knowing its original source, scholars from John Ruskin onwards have positioned the diagram upside down, with the triangle at the top. Suggesting that this diagram might represent a cloud, Judy Egerton continued: ‘the point of view (or point of sight) is the point within the uncompleted circle (or station) at the bottom of the drawing. The longer line across the centre is the horizon line, the shorter line above it is the ground line, and the black triangle is the unidentified flying object in a view (?a cloud)’.2
1
Malton 1775, p.140.
2
Egerton [and Ellis] 1980, p.[5]
Verso:
Currently laid down.

Andrea Fredericksen
January 2004

Supported by The Samuel H. Kress Foundation

Revised by David Blayney Brown
January 2012

How to cite

Andrea Fredericksen, ‘Lecture Diagram: Perspective Representation of a Triangle c.1810–28 by Joseph Mallord William Turner’, catalogue entry, January 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-perspective-representation-of-a-triangle-r1136777, accessed 16 April 2024.