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

ISBN 978-1-84976-386-8

Joseph Mallord William Turner Notes on Light and Shade (Inscriptions by Turner) 1809

Joseph Mallord William Turner 1775–1851
Folio 16 Recto:
Notes on Light and Shade (Inscriptions by Turner) 1809
Turner Bequest CXII 16
Inscribed by Turner in ink (see main catalogue entry) on white wove paper, 107 x 180 mm
Inscribed by John Ruskin in red ink ‘16’ bottom right
Stamped in black ‘CXII 16’ bottom right
Accepted by the nation as part of the Turner Bequest 1856
Turner’s inscription is continued on the verso (D07773); for convenience a full transcription is given here:
Before we can give rules for regulating the power | of lights and shades in a picture, we must consider | what degree of it the bodies themselves are imbued ... with | according to their several positions with respect | to illuminating body | 1 – The intensity Of lights upon any plane |is reciprocally as the square of the distance | of that plane from the illuminating quality body | For example if parallel planes are | at the distance of 2. 3 ft from the illumi | nating point, the intensity of light upon | them would be 1 ¼ – 1/9 | all planes are equally lighted by | the sun at the same time | For this ray being parallel at 600 | the squares are equal at 660 | if the sun-beams fall perpen | upon one face of an Object and inclined [continued on verso, D07773) upon another pl. the intensity of light on | the faces is as the radius to the sine of | the angle in incidence | a plane uniform enlighted | does not appear to an eye in different | situations | P. all shades and shadows of | objects would be equally dark and indi | stinguishable of they received no secondary | or reflected light | P. Everybody participates of ?aspects | of the lights by which it is illuminated for | Blue ray shows upon a yellow producing | a green, red rays upon Blue purple | P. Bodies partake more of the colour | of the sky as they are farther off.
The inscription occupies the right half of the leaf, which has been folded vertically at the centre.
Turner made these notes while preparing his lectures as Professor of Perspective at the Royal Academy. More notes for lectures are on folios 16 and verso and 77 verso–78 of the sketchbook (D07772–D07773, D07835–D07836).

David Blayney Brown
June 2009

How to cite

David Blayney Brown, ‘Notes on Light and Shade (Inscriptions by Turner) 1809 by Joseph Mallord William Turner’, catalogue entry, June 2009, 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-notes-on-light-and-shade-inscriptions-by-turner-r1135725, accessed 18 May 2022.