The top half of the page is taken up with the following notes:
Optica the Horizontal line and Point of sight | all above it Anoptia below Catopica.
The [?descent] of the deity by Pordonne in Campagna of Placentia | broad then long ..
Bramantino first P. by rules | The second without measure but by the eye | The Third by a Grate or Glass set before | The and transferd by lines
The first line condenses three brief chapters of ‘The Fifth Booke: Of the Perspectives’: chapter X, ‘Of Anoptica the First Sight or Reall and Upper Line’, page 203; chapter XI, ‘Of Optica the Second Sight or Reall Middle and Direct Line’, page 205; and chapter XII, ‘Of Catoptica the Third Sight or Reall and Lower Line’, page 206. These concepts are conveyed more directly in a related diagram (page 204), which Turner copied later in the sketchbook (folio 60 verso; D07457).
The second line is taken from chapter XIII, ‘Of the First Deceitfull Sight * Uppermost Perpendicular’, the whole of which is on page 207. Lomazzo notes in rather convoluted fashion:
it representeth to us the figures in a little space from below perpendicularly in the toppe of the vault, perfectly expressing aswell the lower, as the upper partes. But those which stand out in length are (for the most part) so shortened, that the figures seeme broader than they are long, working this strange effect inwards, that heereby they seeme as great as the Life. After which manner the picture of God the Father is done by Pordonone [sic], in the toppe of the roofe of Saint Maries in Campagna of Placentia.
This last is a reference to frescoes in the dome of S. Maria di Campagna, Piacenza, by Pordenone (circa 1483–1539).2
The last line is a summary of the short chapters XXII–XXIIII, respectively ‘The First Perspective of Bramantino’, page 216, ‘Bramantines Second Perspective’, page 217, and ‘Bramantines Third Perspective’, pages 217–18. Turner had noted Bramantino’s name from a preceding passage (folio 42 recto; D07425). The second of these chapters describes an intuitive approach to perspective ‘by meere imitatiõ of Nature, or by working wholy after our own phantasie’. The last appears to have similarities with what Turner called Dürer’s ‘fenestre’ method (see folio 3 verso; D07360):