The Weight of Elements: A Balance in Air and in Water
No element weighs within itself; water falls as an inverted pyramid, fire rises as an upright one
Two entries on the recto develop Leonardo's science of weight in the elements. The main text states that no part of an element weighs within its own element but only weighs, or makes another weigh, where the two join, so it falls from the lighter and is driven out by the heavier; a balance experiment with two equal vessels — one full of water in air, the other full of water in water — is proposed to show how the surrounding medium alters descent. It adds that water fleeing from air descends within it as an inverted pyramid while fire flees upward as an upright pyramid, and that water and air displace one another when a filled vessel is submerged. A small sketch of a balance carrying two vessels, labelled 'water, water', sits at the upper right.
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No element has weight within its own element
Leonardo states that no part of an element weighs while it is within its own element; it weighs, or makes the other weigh, only where the two join, falling from the lighter and being driven out by the heavier. He sets up a proof with two equal vessels on the arms of a balance — one full of water in air, the other full of water in water — to compare their rates of descent, since the vessel in water resists the vessel in air by less than its own weight.
Water descends as an inverted pyramid, fire rises as an upright one
Water that flees from air is said to descend within it in the figure of an inverted (reversed) pyramid, while fire flees from that air in the figure of an upright pyramid. Water is driven upward by earth placed in its vessel, and air is driven from a vessel by the water poured in; when air is submerged, the surrounding water suddenly acquires heaviness. A small balance figure labelled 'water, water' accompanies the note.