On the Point, and the Quadrature of Lunes
A scholastic disputation on point, nothing and void, with geometric figures squaring lunes and rings against a triangle.
The dense main column carries a long scholastic disputation 'On the Point' (Del punto), arguing through an imagined adversary whether the point exists in nature, whether it occupies place, and how point, nothing (nulla) and line relate to one another. A marginal list defines boundary, contact, separation, conjunction and union, and asserts that the moving point describes a line. Surrounding figures treat the quadrature of lunes and rings: triangles inscribed in circles, sectors and spiral 'helices', with claims that a lune and a ring are each equal to a given triangle. One small figure is labelled simply 'Fallacia', and some faint additional sketching appears on the lower fragment.
On this page
On the point: its existence, place and motion
The adversary asks whether the point is in a place or not, whether one or many, movable or immovable. The reply is that the point is in a place without occupying place, exists in nature, is infinite in number, and moves with the place where it resides; its motion describes an imperceptible line divisible to infinity. The point has no middle but is itself the middle and boundary of itself, and its boundaries are nothing.
Marginal definitions: boundary, contact, separation, union
A marginal list orders the terms boundary, contact, separation, conjunction and union. No boundary is part of the thing bounded, nor is separation or contact part of the things concerned. The motion of the point describes a line composed of as many points as there are changes of position, and that motion is not itself part of the line.
A lune and a ring each equal to a triangle
Here the smaller circle equals the remainder of the larger, and the triangle equals that remainder; hence the lune and the ring (anulo) are equal to each other and each is worth the triangle. To restore to the little lune the portion that makes it concave, as much must be restored to the ring, shown below in the fourth figure. The triangle is extended into that figure as m o c, worth the triangle a b c.
A spiral of seven eighths of the circle
The note directs making a helix (spiral) of all the space that contains the seven eighths of the circle. Once made, the wedge (conio) is then to be removed from them. It accompanies a triangle-and-spiral figure inscribed in a circle.
A sector construction marked 'Fallacia'
A group of circle sectors at the left is labelled 1 - 1 - 2 - 2 and marked simply 'Fallacia', a fallacy. Nearby figures mark parts b - c and a ring with semicircle labelled a - b - c where a, b, c are declared equal. These accompany the attempts to square lunes against rectilinear figures.
