A Pyramid Holds One Third of Its Cylinder
Continuing the reshaping of cylinder into slab and the volume of the inscribed pyramid
The text continues the reshaping of a cylinder, drawing the slab n m o p in its proper form, marking again the cylinder's thickness at b o, then extending the slab by 'the seventh of the first' until the whole extension o d contains the cylinder sought. Leonardo then observes that the largest pyramid inscribable in a cylinder is one third of it, so three such pyramids equal the cylinder; a single pyramid built on the cylinder's face and given three times its height contains all three exactly. The page is filled with text and carries no diagram.
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The inscribed pyramid is one third of the cylinder
Leonardo states that the greatest pyramid that can be made within a cylinder is a third of that cylinder's quantity, so three such pyramids equal the cylinder. Therefore one pyramid built on the cylinder's face and given the combined height of the three contains all three exactly, and must be made three times longer than its cylinder.
Spreading the slab n m o p to the cylinder's thickness
The opening lines redraw the slab n m o p, mark the given cylinder-thickness again as b o, and by 'the seventh of the first' extend the slab across the width set at b o; the whole extension o d contains within it the cylinder asked for above.