Prepared in connection with his lectures as Professor of Perspective at the Royal Academy, Turner’s diagram is based on one by John Joshua Kirby (1716–74) in Dr Brook Taylor’s Method of Perspective Made Easy; both in Theory and Practice (London 1768, vol.II, pl.XII, fig.7). Kirby used it to illustrate how to depict circular stairs in perspective. Turner’s lecture diagram would have supplemented existing lecture material.
Blank, save for an inscription by an unknown hand in pencil ‘50’ bottom left.
Supported by The Samuel H. Kress Foundation