On Distillation by the Sun.

A hand-colored ink drawing illustrates the process of solar distillation. On the left, a personified sun with a human face emits yellow rays. A beam of sunlight is directed toward a green glass flask or cucurbite cucurbit resting on a square pedestal. To the right of the flask, a circular green concave mirror, known as a burning mirror, reflects and focuses the light rays back onto the vessel to provide heat for the distillation process.