Cone-and-circle figures lettered d b a and m p o n
Three interpenetrating cone-and-sphere diagrams drawn with the sheet inverted
The sheet, inscribed with the page turned upside-down, carries three figures each built from a pair of cones or pyramids that taper toward a small circle and open toward a larger disc or sphere. Fine radiating lines cross between the forms, in the manner of a study of light or shadow cones meeting a rounded body. The first figure is labelled with the letters d, b and a; the second with m, p, o and n. The third figure at the foot of the page carries no transcribed labels.
On this page
First figure, lettered d b a
The uppermost figure sets a slender cone against a broad disc, with lines radiating from a small circle at one end toward the wide rim at the other, as in a study of a cone of light or shadow. The construction points are marked d, b and a.
Second figure, lettered m p o n
The central figure repeats the double-cone form on a larger scale, its rays crossing at a waist between a small circle and a shaded sphere. The letters m, p, o and n mark points of the construction.