Studies for squaring a curved surface
Circles, squares and cubes with a maxim: return the parts and you remake the whole
The sheet gathers geometric figures aimed at the quadrature (squaring) of a curved surface, lettered a; b; c, alongside pairs of circles and squares also lettered a; b. Twice Leonardo states the same principle: that returning to a whole the parts taken from it restores its entire sum. Further faint sketches, including cubes drawn in perspective and small ruled grids, are present but untranscribed, together with a short column of numbers.
On this page
Three figures for squaring a curved surface (a; b; c)
Three lettered figures a; b; c are set out for the quadrature of a curved surface, headed 'Conception.' Beside them Leonardo writes that if you return to a thing the part you take from it, it returns to its first entire sum. The same idea is repeated in the left margin.
Paired circles and squares
A pair of circles lettered a; b and a pair of squares lettered a; b accompany the quadrature studies. They appear to compare curved and rectilinear figures of comparable measure.
Column of numbers
A short set of numbers, 12 and 13 with the notation 1), is jotted among the figures. It reads as a small calculation attached to the geometric work.
Untranscribed cubes and ruled grids
Along the upper edge and left side are further faint geometric sketches, including cubes drawn in perspective and small ruled grids, that the transcription does not cover. They extend the sheet's play with solid and plane figures.