
Header for a short article on the subject in Penrose's Pictorial Annual, 1902-3, written by George Stuart Littlejohn.
Many of the examples in the volume bear a Littlejohn logo.
A place for show-and-tell, wondering aloud, and wandering the trails of curiosity . . . Comments, corrrections, additional information, fresh insights, other interpretations, more images, or related observations will be welcomed!