Domed churches, a hoisting crane, and quadrature studies
Architectural plans and sections, a braced lifting machine, star polygons, and the squaring of a shield-shaped curve
The verso is dominated by architectural studies: domed, centralized churches drawn in plan and cross-section, arches and star-polygon layouts. A large braced hoisting crane occupies the lower left. The transcribed notes are sparse against this rich drawing and treat geometry: the 'quadrature of the shield,' a rule that lines falling to a curve's periphery meet it between two right angles and, when divided from the curve by a perpendicular, converge to a point (the more remote as the curvature is less), and a plan sketch with eight lettered vertices. A brief prose fragment reads 'and it is begun and drowned by the circumstances'; much of the drawn architecture is not covered by the transcription and is described from the image.
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Centralized churches in plan and section
Domed, centralized church schemes are studied across the upper and left of the sheet, shown both as ground plans and as cross-sections through the dome and arches. These drawings carry no transcribed text and are described from the image.
A braced hoisting crane
A tall lifting machine with a raked, braced frame is drawn in the lower left corner. It is not described in the transcribed notes and is recorded from the drawing.
Quadrature of a shield-shaped figure
Beside a small curvilinear figure Leonardo poses the problem: 'let the quadrature of the shield be given.' The figure is the pointed, shield-like curve whose area is to be squared.
Lines meeting a curve at right angles converge to a point
Make the lines that fall to the periphery meet it between two right angles. Lines divided from the curve by a perpendicular always converge to a point, but so much the more remote as the curvature is less. Illustrated by a partly curvilinear figure divided into sectors.