Canal bridge, a wheel, and a square within a ring
Pen sketch of a bridge on pier supports, a red-chalk wheel, and a squared circle.
The lower half of the leaf carries a pen sketch of a low bridge or trestle over a canal, carried on angled piles, with a note fixing the spacing of its supports. In the middle, in red chalk, a flattened ring encloses a small square, captioned as a square within a ring and glossed 'one will see the round square' — the old problem of squaring the circle. At the top a lightly drawn red-chalk circle with a centre point is labelled simply a wheel. A ruled scale bar with tick marks runs along the foot of the page.
On this page
Bridge over a canal on pier supports
A pen sketch at the lower left shows a low bridge or trestle carried on angled piles over a waterway, with a hatched deck. The accompanying note specifies the spacing of the supports: for every braccio of span, a strut proportioned by a third and a quarter. A ruled scale bar with tick marks runs along the foot of the page.
Squaring the circle: a square within a ring
In red chalk a flattened ring or annulus encloses a small square at its centre. The caption calls it a square within a ring, and the note 'one will see the round square' points to the problem of squaring the circle. The figure sits in the middle of the page below faint mirror-writing.
A wheel
At the top of the leaf a red-chalk circle with a marked centre point is labelled simply 'wheel'. No further explanation accompanies it. The outline is lightly drawn.