Visual illusions, their causes, characteristics and applications (1922)
Luckiesh, Matthew, b. 1883 · New York, D. Van Nostrand company · leaf 110
THE INFLUENCE OF ANGLES 95 of angles is seen in Fig. 58. The two lines forming angles with the horizontal are of equal length but due to their relative positions, they do not appear so. It would be quite misleading to say that this illusion is / A … Fig. 67. — Combined influence of angles and contrasting lengths. merely due to angles. Obviously, it is due to the presence of the two oblique lines. It is of interest to turn to Figs. 25, 26 and various illusions of per- spective. Fig. 58. — Two equal oblique lines appear unequal because of their…
Optical illusions
Internet Archive · Cornell University Library · Public domain (published before 1931). Free to use for anything.
![An illustration from Henry Cornelius Agrippa's Fourth book of occult philosophy, and geomancy. Magical elements of Peter de Abano. Astronomical geomancy [by Gerardus Cremonensis]. The nature of spirits [by Gorg Pictorius]. And arbatel of magic (1655)](https://img.insideoutlibrary.com/img/200/ia-cu31924006718757-218-30.webp)
