72 



HAROLD 0. BINGHAM 



IV; pre 4. (Reprinted from Behavior Monographs, 1911, vol. 1, no. 2, p. 18.) 

 "Perspective of light or 'brightness' apparatus. A, light box; C, D, com- 

 partments of A; B, partition between C and D; E, F, lids of A; G, H, metal 

 carriages carrying tungsten lamps; IJ and KL, tracks for G and H; M, 

 .\. Starrett steel millimeter tapes; O, P, apertures covered by Aubert dia- 

 phragms; R, Bausch and Lomb cooling cell in light box; d, d', metal straps; 

 y, aluminum plate sliding between d and d'; T, tracks for y; V, stop for y; 

 z, steel plate bolted to wooden end of light box; h, screws attaching y to 

 z; s, s, standard brass stimulus plates; p, brass frame about aperture in y; 

 r, hard rubber ring screwed to p." 



