Treatise page with small marginal figures
Mirror-script prose beside a cone, a circle, and a shaded oval
Blocks of mirror-script prose, divided into short paragraphs marked by small circular signs, run down the leaf beside three little pen figures set in the right margin: a narrow cone or triangle near the top, a plain circle at mid-height, and a shaded rounded form lower down. The shapes are consistent with studies of a cone of rays and of light and shade falling on a curved body, though the accompanying text is not transcribed here. Red folio numbers and the oval Institut stamp appear along the outer edge.
On this page
Marginal cone, circle, and shaded body
Three small pen sketches occupy the right margin: an elongated cone or triangle near the top, a plain circle at mid-height, and a rounded form with shading toward its base. Figures of this kind typically illustrate the geometry of a cone of rays and the gradation of shadow over a curved surface. The related prose is present on the leaf but untranscribed in this bundle.