K. 4.8 4.8 8.2 8.3 8.1 9.8
K. 5.1 5.3 7.1 7.7 10.0 10.8
K. 4.7 5.0 8.1 8.6 8.6 9.4
--- --- --- --- ---- ----
Av. 4.9 5.0 7.8 8.2 8.9 10.0

The first two numbers in the first line signify that when an
open distance of 4 cm. was taken, an adjacent open distance of
4.7 cm. was judged equal; but when the adjacent space was
filled, 5.3 cm. was judged equal. Each number in the column of
filled distances represents an average of five judgments. All
of the contacts in Table I. were made simultaneously; in Table
II. they were made successively.


In the next series of experiments the illusion was approached from an
entirely different point of view. The two points representing the open
space were given on one arm, and the filled space on a symmetrical
part of the other arm. I was now able to use a much wider range of
distances, and made many variations in the weights of the points and
the number that were taken for the filled distance.

However, before I began this second series, in which one of the chief
variations was to be in the weights of the different points, I made a
brief preliminary series of experiments to determine in a general way
the influence of pressure on judgments of point distances. Only three
distances were employed, four, six and twelve centimeters, and three
weights, twelve, twenty and forty grams. Table III. shows that, for
three men who were to serve as subjects in the main experiments that