Page:Mind (Old Series) Volume 11.djvu/69

 58 G. S. HALL AND J. JASTEOW : larger numbers) were made, of which only the averages are given in the Table and intermediate numbers above ten omitted. Two other intervals above and below those of the Table were used. The effects of practice are obvious. E. M. H., e.g., on whom but one very incomplete record was made, was most in error, while J. J. and G. S. H., who made most records, are nearest right. TABLE I. 0) I jj ESTIMATED NUMBER OF CLICKS (Averaged). X^ ,_ ^ 5"^ Interval, 0-0895 sees. Interval, Q-Ofri:', - G.S.H. J.J. H.S. J. D. G.S.H. J.J. H.S. .1.1). A.G.B. K.M.H. 2 2 2 2 2 2 2 2 2 2 2 3 3 3 3 3 3 2-86 2-2 2 2 '6 2 4 4 4 3-4 3-25 3-55 3-22 3 3-8 3-6 2 5 5 4-8 4-2 3-75 4-6 3-57 3-25 3-7 4 3 6 5-5 5-5 5 4 5-43 4-29 3 3-7 4 7 7 6-1 5 6 5-5 3-5 5-8 4 8 8 7 7 5-75 6-16 5-6 1-26 4 4 3 9 8-33 8 8 8-1 6 4 8 4-6 10 9 8 8-1 7 8-2 5-7 5-2 5-8 6-25 12 11-66 10-5 11 7 -7r) 11 6-5 5 9 6 16 16-5 14-7 9 11-5 15 10 7 11 8-7 4 20 18 17-8 13-2 15 19-7 11-25 9-2 8 10-2 5 25 22-5 23 17-5 20 13 10-1 12-2 11-7 6 30 29 27-4 24 20-5 23 15 12-5 18 16 8 35 33-3 33 27 20 20 12-5 11 17 40 36-6 37 33 24-5 11 14-7 26 45 41 42 43 26 32 17 30 21 50 34-5 31-5 35 18 26-5 1-1 55 49 34 39 21 60 48 35-6 44 26 26-5 65 57 41 47 l'l 26-5 Counting objects and impressions is a very complex process and slow and hard to teach or learn. (1) The impressions in a series must of course be distinguished from each other. The ear, which does this most acutely of all the senses unless it be touch, discriminate T ^ (Helmholtz) or even -g^ (Exner) of a sec. under exceptionally favourable conditions. These of course are extr limits, hut from iM to 40 beats per sec. can be distinguished by the average ear without fusing into a tone. The actual number of beats is also a function ; that is, in order that their discontinu- ity may be clearly perceived, four or even three clicks or beats must be farther apart than two need to be. When two an- easily distinguished, three or four separated by the same interval approach nearer to the above limit and are often confidently