Folio 2r: Rectangles in a Semicircle; Note on Capacity
A solid's capacity by its inclined position, with a glue-and-millet recipe
This leaf pairs mirror-script prose with a red-chalk diagram of a semicircle enclosing two rectangles, one standing vertical and the other inclined. The accompanying note states that an upright parallelepiped's proportion of capacity depends on how near its position is to its flat, equal-lying rest. A separate red-chalk memorandum gives a practical recipe: to make a cup of glue with congealed millet, or elder flowers, or similar materials.
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Two rectangles inscribed in a semicircle
Within a semicircle Leonardo draws two rectangles, one set vertical and the other inclined. The construction serves to compare the two positions of the same figure.
Capacity of an upright solid varies with its inclination
The note reasons that the standing parallelepiped's proportion of capacity corresponds to how close its position lies to the site of its equal-lying (horizontal) rest. It links the measure of the solid to the inclination of its position, in keeping with the notebook's concern with proportion and weights.
Recipe for a glue-and-millet paste
A short practical memorandum instructs the maker to prepare a cup of glue with congealed millet, or elder flowers, or other similar substances. It reads as a working note toward a paste or preparation.