In making the tests for the first series, the subject removed his finger after each judgment, so that the position of the apparatus could be changed and the subject made to enter upon the new judgment without knowing either the approximate length or the nature of the filling of this new test. With this apparatus no attempt was made to discover the effects of introducing changes in the rate of speed. The only requirement was that the motion should be uniform. This does not mean that I disregarded the factor of speed. On the contrary, this _time_ element I consider as of the highest consequence in the whole of the present investigation. But I soon discovered, in these experiments, that the subjects themselves varied the rate of speed from judgment to judgment over a wide range of rates. There was no difficulty in keeping track of these variations, by recording the judgments under three groups, fast, slow and medium. But I found that I could do this more conveniently with another apparatus, and will tell at a later place of the results of introducing a time element. In these first experiments the subject was allowed to use any rate of speed which was convenient to him. TABLE IX. Subjects P R F Rr 2= 3.8 3.6 2.9 2.8 3= 4.1 4.1 4.2 3.9 4= 4.7 5.1 4.3 4.3 Filled 5= 5.2 5.6 5.8 6.0 Spaces. 6= 6.0 6.3 6.4 5.2 7= 6.8 6.5 6.6 7.0 8= 7.5 7.6 7.2 7.4 9= 8.3 8.1 8.2 8.6 10= 8.9 9.1 8.7 8.5 TABLE X. Subjects P R F Rr 2= 4.0 3.8 3.2 2.6 3= 4.3 4.2 4.4 3.6 4= 4.6 5.6 4.6 4.8 Filled 5= 5.4 6.1 5.6 5.7 Spaces. 6= 6.2 6.4 6.8 6.9 7= 7.3 6.8 7.9 7.2 8= 7.8 7.4 7.3 7.8 9= 8.6 8.0 7.9 8.9 10= 9.3 9.1 8.9 8.5 TABLES IX. AND X. First line reads: 'When the finger-tip was drawn over a filled distance of 2 cm., the subject _P_ measured off 3.8 on the open surface, the subject _R_ 3.6, etc.' Each number is the average of five judgments. In Table IX. the points were set at regular intervals. In Table X. the filling was made irregular by having some points rougher than the others and set at different intervals.