Helmholtz and the Sirens 219
Figure 14.2
Helmholtz ’ s tachistoscope, used to avoid involuntary movement of the eye by very brief illumination of test
images (1866).questions he hoped to resolve, which historical awareness helped him formulate more
pointedly. Thus, his awareness of Young ’ s three-color hypothesis helped him formulate the
relation between human physiology and the purely physical theory of color presented by
Newton. Helmholtz also provided various geometrical representations of color perception
( figure 14.4 ), for which he used the terms “ curve ” ( Curven ), “ color circle ” ( Farbenkreis ),
“ color cone ” ( Farbenkegel ), or “ color pyramid ” ( Farbenpyramide ) in his 1866 Handbuch.^8
In this edition, he does not use the terms “ manifold ” or “ space ” ( Raum ), to which we
will return.
In such diagrammatic representations, Helmholtz was endeavoring to define three inde-
pendent parameters of perceived color, which we now call hue, value, and saturation and