The top two-thirds of the page are takenup with the following notes:
reflection this I deny reflections vary | according to the light and [...] position and | according to the agitation of the surface | of the reflecting medium but to [?consider] | water as glass to define ray and re | flection may be [?imprudent] and to some | appears conclusive becoming we say all | as clear as glass but that is the power | of [?clearness] and not admitting the [?instance] | of a medium which is not which to be | [?between] but the reflecting medium | is a cause not an effect not and | an interference now diff[...]
The passage is the last in a sequence of notes and diagrams which runs back from folio 79 verso (D07487), the penultimate page being folio 73 verso (D07475). 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.