n the narrow line, ad. On the other hand, the fixing of the eyes causes the illusion to disappear with relative facility in fig. 120, and with more difficulty in fig. 121; it will, however, disappear equally in the latter design, if we fix it immovably, and instead of considering it as composed of… … Fig. 121. — The vertical strips are parallel ; they appear convergent or divergent under the influence of the oblique lines. will return in full force. We can indeed succeed in completely destroying the illusion produced by these designs by covering them with a sheet of opaque paper, on which we…
Scientific recreations
Internet Archive · University of California Libraries · Public domain (published before 1931). Free to use for anything.
