UNPUBLISHED SHEETS OF LEONARDO DA VINCI

(Library of Windsor Castle)

THE THORAX AND THE ABDOMEN

This table was likely intended for archival cataloging or for the owner of the publication to manually enter plate numbers and cross-references to other anatomical subjects.

Because a weight does not move except along the line which is most perpendicular to the center of the world Leonardo refers to the "center of the world" as the center of gravity or the center of the Earth, therefore a weight will move so much more swiftly along a given line the further that line is from the said perpendicular. | Motion made along lines which do not pass through the center of this world cannot be of the same velocity nor of the same force, as they lack one of the two principal conditions: namely, velocity and perpendicularity between the line of motion and the line of the horizon. | The closer the line of motion of a weight is to the perpendicular line of the center of the world, the swifter that line of motion will be; | and that velocity will be so much more powerful in its impact; | and that velocity will occupy so much less time. And if this percussion impact or strike is made in the air, that velocity will be maintained longer because the air offers no resistance unless it is compressed by said velocity.

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If air, water, and earth have the same velocity and impact against the same object, that impact will be so much more powerful in one than the other as the material is denser | than the other; | therefore, earth will be more powerful than water, and water more than air. | But if the velocity of the wind that strikes a sail is greater than the velocity of the water that strikes the oars of the same vessel, | the force of the air will be greater than that of the water in proportion to how much its velocity exceeds the density of the water, making it...