ABSTRACT
The Thaumatrope, a very ingenious philosophical toy, invented, we believe, by Dr Paris, is founded on the well- known optical principle, that an impression upon the retina continues for about the eighth part of a second after the object which produced it is withdrawn. The Thaumatrope consists of a number of circular pieces of card, about-two and a half inches in diameter, which may be twirled round with great velocity by the application of the fingers to pieces of silk string attached to two opposite points of their circumference. The principle of the thaumatrope may be extended to many other devices. Those who have used the thaumatrope, must have been dissatisfied with the general effect of the two combined pictures.
