When a spoked wheel is observed rolling behind a picket fence, a striking pattern (the Roget Illusion) is observed that arises as a result of the motion and the persistence of vision. The mathematical description of the illusion is developed and an apparatus briefly described that demonstrates it. The inverse process of de-convoluting a distorted object utilizing motion and the persistence of vision is employed in a device called the “anorthoscope.” The analysis of this device is discussed and a simple instrument is shown.

1.
This is the same Peter Mark Roget (1779–1869) whose name is famously attached to the “Thesaurus of English Words and Phrases.”
2.
W. B.
Carpenter
, “
On the Zoetrope and Its Antecedents
,”
The Student and Intellectual Observer
1
,
427
444
(
1868
).
3.
Henri Bouasse, Vision et Reproduction des Formes et des Couleurs, 2nd ed. (Bibliothèque Scientifique de l’Ingeneur et du Physicien, Delagrave, Paris, 1928).
4.
M. G. J. Minneart, Light and Color in the Outdoors (Springer-Verlag, New York, 1993), pp. 137–140.
5.
If the apparatus is observed from behind, the motions are of a wheel rolling across a ceiling or, alternatively, the entire apparatus reflected in the horizontal plane; the illusion pattern is seen inverted.
6.
J. L.
Hunt
,
B. G.
Nickel
, and
Christian
Gigault
, “
Anamorphic Images
,”
Am. J. Phys.
68
,
232
237
(
2000
).
7.
Joseph Plateau (1801–1883), Professor of Physics at the University of Ghent.
8.
The anorthoscope was not a commercial success because of the expense due to its complexity. Surviving instruments with sets of disks are rare.
9.
Thomas B.
Greenslade
, Jr.
Nineteenth Century Textbook Illustrations LII
,”
Phys. Teach.
30
,
123
125
(
1992
).
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