ing their unreliability. According to Paris, the trick of the Thaumatrope lies not
just in the hand, but lurks concealed in the eye itself, whose nature is revealed
by the device. Paris’narrator, Mr. Seymour, declares to his young charge,“I will
now show you that the eye also has its source of fallacy.”His adult interlocutor,
the local vicar, exclaims“If you proceed in this manner, you will make us into
Cartesians.”Paris provides a useful footnote to explain the term:
The Cartesians maintained that the senses were the great sources of deception; that
everything with which they present us ought to be suspected as false, or at least du-
bious, until our reason has confirmed the report.Mr. Seymour translates the toy’s name to mean“Wonderturner, or a toy which
performs wonders by turning round.”The Thaumatrope’s wonder is“founded
upon the well-known optical principle, that an impression made on the retina of
the eye lasts for a short interval after the object that produced it has been with-
drawn.”The twirling of the card causes the images on each side to appear
before the eye as if present at the same instant, which Seymour describes as,“a
very striking and magical effect.”
As with most philosophical toys, the lessons of the Thaumatrope depended
on the manipulator not only being in control of the device, but also being able to
examine its elements both in motion and stillness. Anyone could see that each
side of the disk presented only a part of the composite image which spinning
produced. Thus the illusion could both be produced and deconstructed by the
child who operated the device. The classic Thaumatrope composite images (e.g.
a bird + a cage; a vase + flowers; a horse + a rider; a bald man (or woman) and a
wig) did not present a moving image at all, but rather a sort of superimposition,
merging two separate pictures into a new unity.
The Thaumatrope displays the fascination produced by an optically pro-
duced image. Paris claims the composite image derives from a“fallacy”of the
eye. Most discussions of persistence of vision claim it results from a“defect”or
“weakness”of the eye. Herein presumably lies at least one basis for the produc-
tion of motion being described as a trick or deception (Talbot says“the camera
is a more perfect trickster than the most accomplished prestidigitator”). The
spinning disc is faster than the eye. The illusion presumably derives from the
lingering, persistent afterimage, by which we see something after it has, in fact,
vanished from our visual field, or, in the case of the Thaumatrope’s composite
image, we see an image which does not strictly correspond to anything in rea-
lity (there is no“bird in a cage”, only a bird on one side of a card and a cage on
the other). This image is the product, Paris seems to claim, of a collusion be-
tween the device and our eye, or, alternatively the tricky device has taken ad-
vantage of the weakness of our eye (C.W. Ceram in fact refers to the“laggard
sense of sight”in describing Plateau’s experiments with afterimages,and Tal-
32 Tom Gunning