Linear Perspective and the Diminution of Forms
A foreshortened pavement, a circle with tangent sight-lines, and a receding baseline
This recto carries three ruled constructions interleaved with mirror-script that is not transcribed in this bundle. At the top, a rectangle divided into cells is crossed by lines converging to a point at the right, a foreshortened pavement or row seen by an eye. In the middle a large circle is touched by tangent sight-lines drawn from a viewpoint, with a small square set on the same axis, and at the foot a tall vertical and a long horizontal baseline carry rays converging to the right past a small hatched rectangle. Together they demonstrate how forms diminish with distance to the eye; further untranscribed writing surrounds each figure.
On this page
Foreshortened pavement converging to the eye
A rectangle ruled into vertical cells is crossed by lines that converge to a single point at the right, turning an even row or floor into a foreshortened perspective. Letters mark the divisions along the base. This is a standard demonstration of how equal intervals shrink toward a vanishing point.
Circle touched by tangent sight-lines from a viewpoint
A large circle is enclosed by straight lines drawn tangent to it from a point at the left, forming the visual angle by which the whole circle is seen. A small square with its diagonals sits on the same axis between the eye and the circle. The construction reasons about the cone of sight cast onto a round object.
Diminution along a receding baseline
At the foot a tall vertical stands at the left and a long horizontal baseline runs to a point at the right, with rays converging past a small hatched rectangle set on the ground line. The scheme shows how a form of fixed height appears smaller as it recedes. The shading marks the diminished figure against the baseline.