A sieve seen from afar; a pulley mechanism
At a distance a sieve's holes vanish and it looks wholly bright; below, a pulley and geared parts.
An optical observation: a sieve through which luminous air passes will, seen at a long distance, appear to have no holes and to be entirely bright, because the eye can no longer resolve its perforations. Beneath the note is a red-chalk drawing of a pulley (carrucola) and associated mechanisms, annotated with the numbers 2, 1(?), 11. The faded chalk text and diagram share the lower half of the leaf.
On this page
A sieve appears solid and luminous at a distance
A sieve, through which the luminous air penetrates, will at a long distance appear without holes and wholly luminous. The perforations are no longer resolved by the eye and the whole surface reads as bright.
Pulley and mechanisms
Below the note is a drawing of a pulley (carrucola) with associated mechanisms, annotated with the numbers 2, 1(?), 11. The parts are laid out with vertical suspension lines.