Bodies falling from higher up seem to descend nearer the eye
The apparent place of a falling body against its field of sky
Leonardo argues that the higher the place from which a body descends, the more, at the start of its motion, it appears to fall nearer to the eye that watches it than does a body descending from a low place. He grounds this in the "field" behind the moving body, the sky against which it stands out: the lower the body, the more distant the field the eye sees it against. Using the eye p and the falling body seen now at e (against sky d) and now low at h (against sky a), he begins to measure the sky occupied from a to d. The diagram shows steep falling lines and a level upper line marked with labelled points.
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A body dropped from higher seems to fall closer to the eye
The higher the place from which the falling thing descends, the more, at the beginning of its motion, it appears bound to descend nearer to the watching eye than a thing that falls from a low place does. The starting height governs the apparent nearness of the fall.
The sky as the field behind the moving body
The effect arises from the field of the moving body, which is the sky against which it stands out. The lower the body, the more distant the field in which the eye sees it, so its background shifts as it drops.
Eye p reads body at e against sky d, low at h against sky a
When the eye p sees the moving body at e it sees it occupy the part of sky d, which seems almost above; when it sees the body low at h it sees it occupy the part of sky a. The passage begins to measure the sky between a and d and breaks off mid-word.