528 
creased, being 20% for the second day, 10% 
for the fifth, and 5% for the ninth day. 
The probable error was used as a measure 
of irregularity. The percentage of decrease 
in irregularity of successive movements was 
not so large in the first part of practice as 
the percentage of gain in speed; but after 
the fourth day the percentage of the de- 
crease had grown until it exceeded the per- 
centage of increase in rapidity, thus demon- 
strating that the psychological order of 
development in voluntary movement is (1) 
rapidity, and (2) regularity. 
The results also showed that during each 
practice period the subject constantly in- 
creased in speed and regularity of move- 
ment until the setting in of fatigue. How- 
ever, when the exercise was continued 
after a short interval there was a renewal 
of the effort and the same results were 
observed to occur, though the period was 
much shorter than in the former case. 
These periods of renewal of energy were ob- 
served to become shorter each time until 
they came to affect almost every alternate 
movement. 
II. Drawing circles —This experiment con- 
sisted in making circles with the free-arm 
movement. A true circle, drawn with a 
compass, 60™" in diameter was placed be- 
fore the subject as a copy. Preliminary 
tests showed that ten circles at one sitting 
gave the best general results. The tests 
were made on seven subjects, extending 
over six days. 
The results showed that with the right 
hand most of the subjects gained in smooth- 
ness of contour in their drawings, both 
during the progress of each practice and 
from day to day; with the left hand the re- 
sults were more irregular. 
Though all gained in the smoothness of 
contour of their curves, yet all did not make 
them of a size corresponding to that of the 
copy. These results brought out three 
types of practice: (1) That in which the 
SCIENCE. 
[N. 8S. Von. X. No. 250- 
subject decreased the size of the circle, both. 
during the progress of each experiment and 
from day to day; (2) that in which the 
size of the circle was increased during the 
experiment, but decreased from day to day ;. 
(3) that in which there was but little varia- 
tion from the copy either during the 
progress of the experiment or from day to 
day. The first two classes were those who 
regarded more carefully the smoothness of 
contour of their own drawn curves than 
they did their correspondence in size to that: 
of the copy. The third class were those 
who directed their attention more especially 
to the size of the curve and who closely ob- 
served the copy each time before beginning” 
to draw their own curves. 
The results also showed an important 
principle bearing on pedagogy—that a short 
exercise often repeated is the best method 
of practice for rapid development of accurate 
adjustment of the muscles. Long practice: 
at writing, drawing, ete., seems to be time 
and energy wasted. Not only are inatten- 
tive habits cultivated, but every wrong ad- 
justment gains a place in the chain of 
subconscious memories, and, therefore, de- 
lays the development of the control over 
the muscles for accurate adjustments. 
IIl. Development of central and untrained 
muscles and less adapted joints—This experi- 
ment consisted in tapping continuously 
with the large toe until it was completely 
fatigued. The make and break contacts of 
an electric key were connected with mark- 
ers so that each movement of the key was. 
recorded on the smoked surface of a revolv- 
ing drum. In this way each phase of the 
toe’s movement could be measured; the 
phases were four, namely, the downward 
movement, the downward rest, the upward: 
movement and the upward rest. 
The average tap-time of the subject. 
studied was on the first day 4367; this very 
regularly decreased until at the close of the: 
practice it was 212°. Likewise, the prob- 
