RECORDS OF MEETINGS 201 



Summary of Papers. 



Mr. Montgomery said in abstract : By using small silver beads strung 

 on a wire in a spectacle frame to reflect light into the eye, we have a 

 simple method which lias many advantages in the study of entoptie 

 phenomena. From the standpoint of psychology, perhaps the most im- 

 portant use of such an instrument is in the study of iris movements. 

 For some experiments, it is well to cover the frame with a black cloth, 

 allowing the light to reach the beads through a slit. If three beads are 

 used, they may be moved back and forth and the intensity of the light 

 increased or diminished until the middle circle of light thrown upon the 

 retina is exactly tangent to tbe other two. Such a contrivance allows a 

 view of both pupils at tbe same time. It also allows careful measure- 

 ment of dilation and contraction and furthermore permits the eye and the 

 body to take an easy, normal position. The use of a single bead with 

 two or three sources of light enables one to diversify the intensity of 

 the circles of light thrown upon different parts of the retina. This is 

 important in determining the parallax of objects in the eye which throw 

 the shadows. Combinations are possible with this arrangement and other 

 experiments, Purkinje's for instance, and the beads may also be used for 

 throwing circles of lights from colored globes upon the retina. These 

 circles may be superposed, the different parts of the retina compared as 

 to color sensation, the effect of contrast brought out, etc. 



Mr. Wallin detailed the experimental results of two simple methods 

 of investigating the preferred length of auditory intervals ; a method of 

 impression, in which a preference was reached by successive comparisons 

 of pairs of metronome clicks in a definite order ; and a method of ex- 

 pression, in which the preference for musical tempos was determined by 

 measuring the durations between the responses (stamps of the foot) 

 made to musical selections by the gallery patrons in theaters. The re- 

 sults showed, among other things, that the average interval preference 

 with metronome clicks corresponded precisely with the average tempo 

 of the most vigorous responses to musical rhythms (0.51 sec.) ; that the 

 very general tendency to rhythmize recurrent auditory impressions of 

 the same intensity (metronome clicks) often rested on an ascertainable 

 qualitative basis; that the tendency to perceive different lengths of 

 auditory intervals as indifferent or neutral is infrequent; that instead of 

 selecting a definite, invariable central tendency in respect to interval 

 preferences, the subjects can be arranged most naturally into a number 

 of types (slow, medium, fast, rapid) ; that the absence of a clear, definite 

 central tendency is due to the fact that the preferences are determined 



