Page:Popular Science Monthly Volume 51.djvu/780

equal one of fifteen years not so trained. Four of the teachers place the gain at from forty to fifty per cent in study power. One teacher (class position 44) puts the gain at one hundred per

Explanation of Marks on Voluntary Attention Chart.
21,600 measurements of 2,700 individuals.

The error to two inches may be read in tenths of an inch at right-hand end of horizontal line, at the left end read up the lines are five per cent apart; 0 per cent arbitrarily placed at eighth year; vertical lines divide year spaces fourth to twenty-first.
Line No. 1 (at thirty inches and eighty-five per cent).—Externally sustained attention. All those reputed by coworkers to be superior are at or above this line by test No. 2.
Line No. 2.—Voluntary attention. Average line of centers of groups trained in the schools of many States in the Union as well as Europe.
Line No. 3 is the high limit of the above and ends in A. × marks the individuals through which the line is drawn. From fourth year to fourteenth all are females. From fifteenth year up all are males. ? Marks the rather doubtful lower limit of groups.
⊖	Marks center of composite drawing, average age eleven. ⌃⌄ High and low limit marks.
✠	Marks the center of three hundred and seventy pupils trained by free-hand drawing as a science study.
○	Marks known positions.
━━	Movement between measured centers.
┈┈	Supposed movement.
oA	Figure painters measured in the order named: E. A. Bell, Clark Crum, C, C. Curran, Kenyon Cox, Joseph Boston, Arthur B. Davies, Henry Prellwitz.
oE	Fifty-three teachers. ⌃⌄ High and low limit marks.

cent in geometry, claiming to have covered certain ground satisfactorily in half the time usually needed for a class without the special training.

By imagining line No. 3 (the high limit of group) prolonged downward and to the left, three years, and line No. 2 treated in the same way to the same age (one year), it will be seen that at the age of twelve months children are almost infinitely separated