(Farbenmisch-Apparat nach Kirschmann)
These wheels imprinted with different colors and patterns
were spun at different speeds and in opposite directions
to demonstrate the principles of color mixing. Disk I appears
to show that exclusion of one color produces a residual
complementary color; Disk II produces complementary colors, one in
the center, the other in the periphery of the disk; Disk III and
others are used to show mixed colors, transitions from one hue to
another, etc. When these disks are set to be moved independently
from the main axis, they show a continuous transition from one
color to another, moving color rings, and other "surprising"
appearances..
(demonstration, apparatus, color phenomena)
Source: Zimmermann, E. (1903). XVIII. Preis-Liste ber
psychologische und physiologische Apparate. Leipzig: Eduard
Zimmermann. 5.