In the movements for which the time was recorded the distances varied, according to the subject, from six to eighteen inches, and varied at times with each subject.  In the experiments without time record, A., B., C., E., F. and H. reported that they were able to move the images apart to ceiling and to floor, or to the opposite ends of the room, and to hold them there both in consciousness at the same time without either alternation of attention or eye movement, a tendency to which was felt but was inhibited.  I. held them two feet apart without fluctuation of attention.  A. reported:  “I tend to turn my body to left or to right when I move the images in either of these directions.”  C., H. and I. said:  “The eyes diverge when one image moves slowly to the right and one to the left.”  D. found a slight movement of the eyes which could be detected by the fingers placed lightly on the lids, when the attention was alternating between the images.  K. had convergence and divergence of the eyes for crossing and separation respectively and he was accustomed to run his eye over the outline of the image.  Strain in the scalp muscles was reported by A., B., E., F. and G. The up-and-down movements were universally characterized by a feeling as if one eye tended to move up and the other down.  C. unconsciously inclined his head to the left in such movements as if to make the line of the two eyes parallel with the direction of the movement.

E., when holding the images two feet apart, had a strong feeling of difference of accommodation when alternating in observation and so judged the two to be in different planes.

When the movement seemed difficult the strain was greater, and when an image became dim the effort to restore its brightness or its distinctness of outline was accompanied by a feeling of bringing it nearer by accommodation and near focusing.  J. found that the two images approached each other when he attempted to secure greater vividness.  An analogous instance is that of A.G.C., a subject quoted in ‘Mental Imagery of Students,’ by French.[4] In calling up the image of a die this subject held up his hand as if it held the die.  When there was no sense of strain the hand was fourteen inches from his face, but when effort was made to image all the sides of the die at once he unconsciously moved his hand to within four inches of his eyes.  French says in this connection:  “Situation depends on the attention involved and the inference is near that this phenomenon may be connected with feelings of convergence and accommodation which so often accompany concentrated visual attention.”

   [4] French, F.C.:  PSYCH.  REVIEW, 1902, IX., p. 40.

The movements were assisted by mentally saying, ’this image is here, that image is there,’ in the case of D., G., H., I. and K.; or, at times, by articulating the names of the image, or of the color when the image was of a colored object.  I. found it easy to hold outlines, but in order to retain colors in the movements of separation, he had to speak the names continually.  H. also repeated the names continually, as, for example, ‘violet here, orange there.’