Hering's color blindness apparatus
Date: circa 1893
Inventory Number: WJ0033
Classification: Color Blindness Apparatus
Dimensions:56 x 42.5 x 22.5 cm (22 1/16 x 16 3/4 x 8 7/8 in.)
box: 57 x 43 x 23 cm (22 7/16 x 16 15/16 x 9 1/16 in.)
central tube diameter: 2.8 cm (1 1/8 in.)
Accessories: lenses and reflectors
DescriptionInstrument consisting of three poles and one tube running through the roof of a box and an adjustable screen at the bottom of the same box. Screens are suspended on each of the three poles and on the assembly at the bottom. Those suspended on the poles have vertical axes of rotation; that at the bottom has a horizontal axis.
The wooden box appears to be made of maple and is varnished black inside. The top of the box is sloped, and the sides are hinged to the back. The front panel is fastened to and detached from the box through a hook and eye on each side.
The three thin poles are suspended through the top of the box. Two are identical and are positioned on opposite sides of the box. At their tops are circular brass knobs; at their bottoms are circular platforms. Suspended right above the platforms are white screens. The third thin pole is shorter, with a concentric hollow brass pole that can be slid up and down and fastened into place by means of a screw. Atop this pole is the same brass knob, but right below that knob is fastened a thin black disc, also fastened by means of a screw. Another white screen is suspended near the bottom of this pole.
The central tube rests on a small box that is fastened to the wall. On this box is the nameplate of the maker. Plates are screwed each side of the box and the bottom. On top of that box is another box that supports the tube. The tube itself has a disc assembly at the bottom. Jutting out of the disc is a screw with a cord that runs to and then through a small tube that connects to the outside of the box, where it culminates in a ball.
At the bottom of the box is another screen, this one with a horizontal axis of rotation. The position is also adjustable and fastenable with two knobs on either side.
Signedengraved on inside: R. Rothe / Prag
FunctionThe test this machine facilitated was what Mary Collins, in her book Colour-Blindness (London: Kegan Paul, Trench, Trubner & Co., Ltd., 1925) has described as a "color equation test," that is, the subject would be asked to adjust the intensity of the green and the hue of the red until the colors matched up. If the subject said they were able to match the colors, they were deemed colorblind (Collins 95-on).
The screens would have color plates to reflect colored light. According to "The Adjustment of the Hering Color-Blindness Apparatus" by Cowdrick and Winfield (1919), the subject would look into the tube and see a circular field divided into half red and half green. The red would come from the bottom reflector, while the green would come from the reflector on the right side of the instrument. A blue reflector on the left side of the instrument would be rotated in order to change the hue of the red semicircle.
Historical AttributesThis instrument was listed in Hugo Münsterberg's 1893 World's Fair pamphlet, Psychological Laboratory of Harvard University (Cambridge, MA: Harvard University, 1893): available here, with image here.
Primary SourcesOriginal documentation of the apparatus can be found here.
This is also listed in Hugo Münsterberg's 1893 World's Fair pamphlet, Psychological Laboratory of Harvard University (Cambridge, MA: Harvard University, 1893): available here, with image here.
ProvenanceDepartment of Psychology, Harvard University.