These notes predominantly in French but with interventions in English are not transcribed here in view of Turner’s imperfect French and transliteration. Together with the diagram below them on this leaf they are taken from Jan (Hans) Vredeman de Vries, Perspective, part 2, Leyden 1605, preface and pl.18. Turner usually used the British Museum’s library for such works; in this instance his likely source is now in the British Library. Vredeman de Vries (1527–circa 1607) was most notable for his assertion that the basic principle of perspective is the existence of vanishing points on which all lines converge, as demonstrated in the diagram where they join at a point on the horizon line
Below the drawing, Turner has written ‘by crossing the work square it makes almost ... | thing possible’.