Pseudo Isochromatic Plates for Testing Colour Perception diaries [Jules Verne Encyclopedia] The JVE

[Jules Verne Encyclopedia] The JVE also cites a copy paired with The Vanished Diamond

spine also slightly toned

and are numbered 1-11

Text laid out within red lined frames

Paul-Émile Botta and Austen Henry Layard

Pseudo Isochromatic Plates for Testing Colour Perception diaries [Jules Verne Encyclopedia] The JVEPhiladelphia: Beck Engraving Co., 1940. Book of folding colour plates made up of dots with numbers in contrasting colours on each one. Includes the instructional slip for usage. Original black cloth with gilt lettering to front, housed in the blue cardboard box which is split at some joints. Lettering on spine somewhat faded.