The angles were drawn with black india ink on white cards 10 cm. square and exhibited to the observer in the Michotte tachistoscope. The observer reproduced the angles with a pencil on a piece of white paper, 10 cm. square. The position of the reproduced legs of the angle was then measured. The size of the angle and the position of the bisector were computed subsequently. Position was measured in terms of a circular protractor placed in a vertical plane and rotated until 0° was uppermost. The protractor was also turned so as to read in the clockwise direction. Twelve sizes of angles were used.
Proceedings of the Iowa Academy of Science
©1930 Iowa Academy of Science, Inc.
Collins, William B.
"The Influence of Position on the Apparent Position, Size and Form of Angles,"
Proceedings of the Iowa Academy of Science, 37(1), 319-323.
Available at: https://scholarworks.uni.edu/pias/vol37/iss1/89