The whole page is taken up with the following notes:
rays converging [?than] diverging but | when the rays of the [?atmosphere] one [...] | [?striking] by an [...] object the | power of the reflected prom[...] is | increased and the reflected power of the | Sun gives the inverted substance | most defined and that reflected [?having] | to issue as it were from a point or | the shadows of the trees are not shadow | without the [?intercepted] the shadows | [?formd] on that wall by the Suns ray | then they are positive but the form | of the object from the suns ray or direction | the reflected ray is inverted and [...] | contra[?dicted] on [...] wall of forms and no | part of that in shadow but in shadow from | the Sun and its dark reflected in the water
The passage is part of a sequence of notes and diagrams which runs back from folio 79 verso (D07487) to folio 72 verso (D07473). The previous page of notes is folio 76 verso (D07481), and the next is folio 74 verso (D07477); there is a diagram on folio 76 recto opposite (D07480), to which the text is related. The semi-diagrammatic drawing of a boat on folio 81 verso (D07491) also appears to belong with these notes, concerned with sunlight or light in general in terms of reflections and the casting of light and shadow from polished objects or bodies of water. They relate to Turner’s fifth Royal Academy perspective lecture, on reflection and refraction.
Davies 1994, p.289.