Two types of work, conducted side by side in the same room, were settled upon as the most fruitful fields for the first experiment. The work chosen was that of inspecting shells before they had been loaded, and of gauging them for head-thickness. This work was being done by 330 girls, two thirds of whom were engaged in inspection and one third in gauging. The work of inspecting shells was done at a table constructed like an upturned, shallow box. Upon this table was dumped a large box of brass shells, not yet loaded, and all of exactly the same kind. The work of each girl was to inspect these shells and throw out those that were defective. A girl would first gather up a handful of shells, being careful to have them all pointing in the same direction. Then she would put both hands around the shells and turn them up so as to expose their insides. She would then look down into every shell for dents, scratches, stains, and other very minute defects. When any such defect was discovered the shell was extracted from the pile and thrown into one of three or four “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 rolling, exposed its lateral surface and was closely scrutinized for scratches, dents, oil 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. This operation required good eyesight (in order to distinguish defects, which frequently were so minute as to be indistinguishable to all but the best of eyes); keen visual discrimination (the ability to determine, with a few glances, which shells were defective); quick reaction (ability to extract, as quickly as seen, the defective shell and toss it into the appropriate box); accuracy of movement (ability to pick out the right shell from a closely held handful); steadiness of attention (ability to prevent bad shells from slipping by or unduly lengthening the operation). A set of eight tests was selected for the body of the experiment. The first was a simple eyesight test. The second was a card sorting test. The subject was given a pack of 49 cards, upon the face of each one of which from 7 to 12 letters were distributed promiscuously. Twenty of the cards contained the letter “O” and the rest did not. The subject was asked to sort these into two piles, those which had “O” on them and those which had not. The time required for this performance was taken and the number of errors recorded. The object of the test was to bring out the subject’s ability to pick out the essential element from a more or less heterogeneous collection of elements, and also, in some measure, to bring out the deftness of the subject in handling cards.