On Motion: Weights Falling Through Ever-Denser Air
Bodies dropped one below the other draw together, and the leading body undulates the air it opens, leaving a void behind.
Headed "On motion," this text-only page collects three linked propositions on falling bodies and the air they move through. Leonardo argues that two equal weights dropped one directly beneath the other will, over a long fall, consume the gap and come to touch, because the lower body always meets denser air while the upper falls through the rarer air it leaves behind. He adds that the leading body must open and undulate the air, part of which flees upward in eddies to strike the second body, while fresh air rushes in to fill the void left behind. A separate annotation, not part of the transcription, runs vertically along the inner margin.
On this page
Two weights dropped in line draw together as they fall
If two equal weights are placed one perpendicularly beneath the other and released at the same instant, over a long descent they consume the interval between them and come to touch one another. Even tied a braccio apart by a thread and dropped together, they still close over a long distance, because the lower body is always in denser air than the one above.
The leading body undulates the air and leaves a void behind it
The air grows denser at every degree of its lowness and rarer at every degree of its height. The first body makes the effort of opening the air and setting it undulating; part of that air flees upward, opposing and striking the second body with eddying motions, while the air above flows in to fill the void left behind the leading body.
An untranscribed note in the inner margin
A further line of writing runs vertically along the inner margin, set apart from the main columns of text. It is not included in the supplied transcription, and its content is not reproduced here.