The Weight and Pressure of Water in Vessels
Whether water's weight bears on a submerged hand or man, with aphorisms and word-lists
A crowded sheet of text and small diagrams exploring the weight and pressure of enclosed water. Leonardo states that an element does not weigh within its own element except by percussion, then poses the questions whether the weight of water in a blow-pipe rests on the hand beneath it, and whether ten thousand pounds of water would press on a man lying at the bottom of the vessel. Using a lettered bag a-c-b he argues the bottom feels no water-weight, and with a heap of logs and an hourglass he shows why only the water directly above a hole issues from it. Interspersed are two moral maxims, brief word-lists, small vessels labelled with wine, oil and water, a note that illuminated air fills with infinite images, and the name Giovanni Battista.
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An element weighs in its own element only by percussion
Leonardo states that an element does not weigh within its own element except by percussion. As an example, air blown by bellows into the surrounding air penetrates the air facing it, and likewise water is penetrated by other water falling upon it.
Does the weight of water rest on hand or submerged man?
Two paired questions ask whether 100 pounds of water in a blow-pipe-like conduit leaves its weight on the hand held beneath it, and whether the weight of ten thousand pounds of water would rest on a man standing at the very bottom of the vessel. Both are posed with reference to the vessels drawn above.
Why only the water above a hole escapes it
Giving escape to enclosed water at point b, only the water directly above the hole along the perpendicular issues out, because the surface enclosed between air and water moves more easily than water pent between two waters. As with a great heap of tilted logs the upper ones move first, and an hourglass pours its red powder before the white.
A lettered bag whose base feels no water-weight
If the bag a bears 10,000 pounds above it, the bottom b c feels nothing of that weight: since the water rests on the bag and the bag tends to rise, the water spills over the top, so the base feels no water-weight, only the air beneath.
Illuminated air fills with infinite images
Beside a note on a crosswise-suspended weight swinging past its rest point, a second remark states that the air, as soon as it is illuminated, fills with infinite images (species), of which the eye makes itself a lodestone.
Two moral maxims
Among the notes stand two aphorisms: 'He who possesses more must fear the more not to lose,' and 'To command is a lordly work; to labour is a servile act.' Short word-lists (to evacuate, digression, lethal, local) and the name Giovanni Battista appear nearby.