Ultra Scarce 1940s Glenn Colorule for Testing Color Vision oval dish allowing for control of the

allowing for control of the arms

and there is a red dyed bone hook included

Tiny text on all of them reads "Registered" and on a few is printed them reads Copyright 1896 F

I myself might be inclined to use it as a vase rather than a watering can (or simply to put it on a shelf to display as an object) but the handle on the back certainly makes it functional for watering the plants

and those big pencil-drawn spots drawn on the larger horse

Ultra Scarce 1940s Glenn Colorule for Testing Color Vision oval dish allowing for control of theI have found a bunch of academic papers and studies discussing the use of the Glenn Colorule, but can't find even a picture of another out there anywhere. There are records of in a few academic libraries, so I know it was produced by s explained on the box text, it was made to be used to test the color vision of observers, to test the quality of light sources, and or to demonstrate disagreement caused by "pseudo," or false, color matches. There's a