SELECTING GIRLS AS ASSEMBLERS 
57 
in order to get the right part to the right space in exactly 
the right position. In one case, a difference of one thirty- 
second of an inch had to be detected. The girl who can 
detect this difference at a glance is far more successful 
than the girl who has to try the piece out first in one posi 
tion and then another until the proper fit is found. In 
order to detect these qualities, a test for the perception of 
°dd shapes and sizes was devised. It consists, like the 
dexterity tests just described, of a board with pieces 
cu t out, except that in this case the pieces are of odd 
shapes. Some pieces are quite different in shape, but 
some, almost alike in shape, differ very slightly as to 
size. When the test is given the pieces are dropped 
into the cover of the form board and arranged there ac 
cording to a predetermined scheme. Then the subject 
ls asked to size each piece up carefully and put it into its 
proper space, making as few mistakes as possible. 
It is very interesting to watch the various subjects take 
this test. Some girls see at a glance where each piece 
belongs. Others have not the least conception of the re 
lation between certain shapes and certain spaces, but aim 
lessly try out each piece at one opening after another 
until, by chance, the right space is hit upon. 
Besides the mental qualities just described, the work 
°I assembling requires strong hands. In order to deter- 
m ine roughly the strength of the hands, a grip-testing in 
strument or hand dynamometer is used. Each girl is 
S'Ven six trials, three with her left hand and three with 
ber right. The number of pounds registered in each trial 
ls recorded and the average for each hand constitutes the 
re cord. 
The conditions under which this experiment was con 
ducted represent a departure from the usual procedure.