Squaring curved figures, continued, with a measuring-wheel note
Lune and polygon geometry alongside a gear sketch and a note of 53 1/3 miles at 20 teeth per wheel
The verso continues the recto's study of squaring curved figures, with more lunes, polygons inscribed in circles, and circles set in squares, and short rules for reducing a curved figure to a square. Turned in another direction, the sheet carries a toothed gear-wheel and a note reading 53 and 1/3 miles at 20 teeth per wheel, the record of a distance-measuring device. A built structure is sketched at the upper left, and the leaf is faded overall.
On this page
Square the curve first when the given square will not fit inside it
A short rule for the quadrature of a curved figure: if the square drawn from the curve does not fit within that curvature, first square the curve and then subtract the given square from it. It sits among a column of circular sectors used in the same demonstration.
The greatest circular figure equals the oval surface
With the sheet inverted, two figures labelled a b and c d are compared, a b being said to equal c d in both cases. Leonardo concludes that the greatest circular figure equals the oval surface.
Measuring wheel: 53 1/3 miles at 20 teeth per wheel
Beneath a drawing, turned from the main text, a note records a distance of 53 and 1/3 miles reckoned at 20 teeth per wheel. It accompanies the toothed gear-wheel drawn on the sheet, the mechanism of a distance-measuring or odometer device.
Sketch of a built structure
At the upper left a small perspective sketch of a built structure is drawn among the geometrical figures. No transcription accompanies it, so it is recorded here only from the drawing.