The sun's image on bubble-like waves and the sphere of a dewdrop
Wide-angle reflection from half-sphere waves; a lead cube submerged in dew keeps its roundness
Leonardo considers waves shaped like half-spheres, like the bubbles on water, and argues that the images of the sun they send to an eye on the shore would converge at a very wide angle. He then turns to a dewdrop as a model of the sphere of water, in which many cases of that sphere's behaviour may be studied, including how it can contain a body within itself without losing the sphericity of its surface. He proposes an experiment: submerge a lead cube the size of a millet grain on a very fine thread into the droplet, which keeps its original roundness while merely growing by the cube's volume. Sketches of the sun, the eye, and a labelled dewdrop with lead accompany the notes.
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Wide-angle reflection of the sun from half-spherical waves
If the shapes of the waves were half-spheres, like the bubbles of water, the convergences of the sun's images that leave those waves and come to the eye would form a very wide angle, when the eye is on the shore of the sea lying between it and the sun.
The dewdrop as the sphere of water containing the earth
In the well-rounded dewdrop many cases of the function of the sphere of water may be considered, including how it contains within itself the body of the earth without destroying the sphericity of its surface.
A submerged lead cube does not destroy the drop's roundness
Leonardo proposes taking a lead cube the size of a millet grain, joining it to a very fine thread, and submerging it in the dewdrop. The drop will be seen not to lose its original roundness, though it is made larger by as much as the enclosed cube.