Joseph Mallord William Turner

Prepared in connection with his lectures as Professor of Perspective at the Royal Academy, Turner’s diagram is based on a plate from Dr Brook Taylor’s Method of Perspective Made Easy; both in Theory and Practice: in Two Books (London 1768, vol.II, pl.III, fig.3) by John Joshua Kirby (1716–74). Kirby’s illustration showed how to prepare a representation ‘of objects which lie flat upon the ground, or that are in Planes perpendicular to the Picture’.1 More specifically, it demonstrated ‘how to find vanishing points of lines which tend to the horizontal line’, as for example in ‘Case III. Of a line parallel to the bottom of the picture’. According to Maurice Davies, this diagram corresponds to a section of Turner’s lecture manuscripts containing notes on methods, primarily based on Kirby, which were used to support other lecture texts when examples of perspective were required.2

Technical notes:

Peter Bower writes that sheet is Imperial size Whatman paper made by Finch and Thomas Robert Hollingworth, at Turkey Mill, Kent. Bower notes: ‘This paper is very heavily sized and bears some relationship to the Parchment Substitute papers produced by various hand made papermakers in the nineteenth century (and into the twentieth) for legal documents. Sometimes papermakers don’t quite keep up their quality control. In the case of this particular sheet [and about nine others from the same batch also used by Turner for his diagrams] the mould has been left, probably overnight, without being cleaned and small amounts of pulp have dried between the support bars under the mould cover and the two layers of woven wire making up the cover. This affects the drainage of the sheet during formation and leaves a clear impression of the mould’s actual structure and construction’.1

Verso:

Blank, save for an inscription by an unknown hand in pencil ‘37’ bottom left