Joseph Mallord William Turner

Lecture Diagram: ‘Euclid’s Elements of Geometry’, Book 1, Proposition 5 and Book 4, Proposition 5


In Tate Britain

Prints and Drawings Room

View by appointment
Joseph Mallord William Turner 1775–1851
Graphite and watercolour on paper
Support: 585 × 873 mm
Accepted by the nation as part of the Turner Bequest 1856
Turner Bequest CXCV 34

Catalogue entry

Prepared in connection with his lectures as Professor of Perspective at the Royal Academy, Turner’s diagram is based on an illustration from Samuel Cunn’s Euclid’s Elements of Geometry (London 1759, Book 1, Plate 1 and Book 4). The left figure illustrates Proposition 5 from Book 1: ‘Theorem: The angles at the base of an isosceles triangle are equal between themselves: And, if the equal sides be produced, the angles under the base shall be equal between themselves’.1 The right figure – inexplicably inscribed by Turner ‘Circle within a Triangle’ – is a portion of Proposition 5 from Book 4: ‘Problem: To describe a circle about a given triangle’.2 See Tate D17003; Turner Bequest CXCV 33 for the remaining portion. There are sketches of each Proposition in Turner’s lecture notes.3
Cunn 1759, pp.8–9.
Ibid., pp.105–6.
Turner, ‘Royal Academy Lectures’, circa 1807–38, Department of Western Manuscripts, British Library, London, ADD MS 46151 V folios 10, 18 verso, 21.
Technical notes:
Peter Bower states that the sheet is Colombier size Whatman paper made by William Balston, at Springfield Mill, Maidstone, Kent.1
Notes in Tate catalogue files.
Blank, save for an inscription by an unknown hand in pencil ‘14’ bottom left.

Andrea Fredericksen
June 2004

Supported by The Samuel H. Kress Foundation

Revised by David Blayney Brown
January 2012

Read full Catalogue entry

You might like

In the shop