Page:Popular Science Monthly Volume 29.djvu/235

Rh nothing more than to estimate, but this must be done with the utmost attention.

Whoever has for any length of time tried seriously to guess correctly will be surprised to find that his guesses will soon grow to be generally correct, whereas at the start they were often erroneous. Only when the number of objects seen exceeds nine will mistakes again occur more frequently. However, further practice in estimating greater numbers of small objects will soon cause considerable improvement even here. Many, however, do not succeed in estimating correctly beyond ten, probably because the attention is not sufficiently concentrated at the time, and as it is necessary, at the start at least, that one's whole attention be closely given; only after having attained some degree of proficiency will the exercise of this power no longer prove fatiguing.



In order to practice this kind of counting, dots and small circles were drawn on white paper squares. Some of these dots were arranged symmetrically, others were irregularly placed. These were glanced at for a moment, and proved of considerable aid in acquiring the art. A good deal depends on the arrangement of the dots. A card-player