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DEPARTMENT OR EXPERIMENTAL PSYCHOLOGY. 
In charge of Prof. J. McK. Cattell. 
68. INSTRUMENTS FOR PSYCHOLOGICAL TESTS, which may be 
made by visitors upon themselves. These are: 1. For 
Sharpness, on Sight; 2. For Color Vision; 3. Perception of 
Weight; 4. Dynamometer Pressure; 5. Accuracy of Move- 
ment; 6. Pressure causing Pain; 7. Time of Perception and 
Movement; 8. Memory; 9. Mental Imagery; 10. Associa- 
tion of Ideas. Visitors are invited to use the instruments ex- 
hibited, with each of which will be found instructions and 
blanks for making records. 
69. APPARATUS for studying the dependence of sensations on 
the time, relations and combinations of colors. This is an 
example of apparatus used in psychological research. With 
the wheel-chronometer any color or combination of colors 
may be exhibited for a given time (to the one ten-thousandth 
of a second) and of a given intensity and area. The instant 
at which the color appears is registered on the chronoscope, 
and the resulting sensation may be studied and measured with 
help of the rotating disk. The rate of rotation of the disk 
may be adjusted and exactly determined, and it may be viewed 
for a given time (say one one-hundredth of a second). 
DEPARTMENT AOR (PHYVSIOLOGY- 
In charge of Prof. John G. Curtis. 
INSTRUMENTS ILLUSTRATING METHODS OF INVESTIGATION 
in the movements, in healthy or diseased living men, of the 
heart, of the arterial pulse, of the muscles, and of the chest- 
wall. 
70. Drum-Kymograph. 
fire uiree Bextra Drums: 
4 glass covers, 4 supports, gummed papers, I stand,1 lamp, 
I rubber tube, I knife, for above. 
72. Metronome-Interrupter, for marking intervals of time. 
73. Chronograph, for recording the same. 
1 Morse key, 2 Grenet cells, copper wires, for above. 
