Cone of Shadow Cast by an Illuminated Sphere
Rays from a broad source above a sphere produce a hatched pyramid of shade below
A large sphere occupies the centre of the sheet, its body divided by horizontal bands and carrying several letter labels. Rays drawn from a ruled line of points at the top converge on the sphere and continue past it, generating a broad triangular region of shade rendered in dense diagonal hatching below. The figure analyses the pyramid of shadow, its darker core and the graded penumbra to either side. The framing mirror-written Italian is not transcribed in this bundle, and further untranscribed text is present.
On this page
Sphere lit from above and its shadow pyramid
Rays issue from a row of points along a ruled line at the top of the page and cross onto a banded sphere at the centre. Beyond the body the rays diverge, bounding a large hatched triangle of shade whose densest tone lies along the axis. The construction shows how an opaque round body throws a pyramidal derived shadow.
Explanatory text (untranscribed)
Passages of mirror-written Italian occupy the top of the sheet and several lines beneath the figure, keyed to the lettered points of the construction. This text is not supplied in the bundle and is not transcribed here.