A FIRST EXPERIMENT 
2 5 
or four appropriate scrap boxes. The entire handful was 
then turned over, and the head of every shell examined for 
various defects. The shells were then held in a horizontal 
position on the left hand, and allowed to roll from the pile 
into the right hand. Each shell, in the process of rolling 
from one hand into the other, exposed its lateral surface 
and was closely scrutinized for scratches, oil dents, stains, 
and other defects. The good ones were taken in the right 
hand and dropped into a pocket at the right side of the 
table, through which they fell into a box below. 
An analysis of this operation showed that it required the 
following qualifications: 
1. Good eyesight. The defects to be detected were 
often so minute as to be indistinguishable to any but the 
best of eyes. It took the experimenter almost a minute 
to see one of the most common defects which these girls 
were required to notice in an instant. Any weakness 
of the eyes or marked difference between the two would 
be likely to show bad results in the inspection. 
2. Keen visual discrimination. Good eyesight is not 
sufficient. The inspector, looking at a whole handful of 
shells, must, with a few glances, be able to recognize those 
which are defective and remain oblivious to those which 
are not. 
3. Quick reaction; that is, the ability to extract, as 
quickly as seen, the defective shell and toss it into the 
appropriate box. 
4. Accuracy of movement, required in picking out the 
right shell from the closely held handful. This requires a 
very peculiar kind of deftness, and, in order to facilitate it, 
many of the girls allow their finger nails to grow to an 
unusually long and sharp point. 
5. Steadiness of attention. The least wavering of the