The improvement consists in inserting in one, or, if a still greater change be desired, in both sides of the card, two strings, as seen in Fig. 1; viz. A D and A E, which united at A, form a common string for twirling the card. The cord A D is elastic, while the string A E is incapable of being stretched. If, therefore, while the card is in the act of spinning, the cord A D be pulled with an increased force, it will take the position D C, while the inelastic string A E will at the same time assume that of E C. The consequence of which will be that, instead of the card spinning on an axis in the direction A B, it will now spin on that which is in the direction C B, and we shall accordingly see the images on the opposite sides of the card in different positions, with respect to each other; at one moment the bottle will be seen in the hand of the drinker as represented in Fig. 2, and in the next, at his mouth as shown in the cut below: [Illustration: Fig. 3. Man with bottle at his mouth.] while, by alternately tightening and relaxing the string, the figure will be seen in the very act of raising and lowering the bottle. Mr. Seymour having explained the principle of his improvement as we have above related, proceeded to exemplify it by a series of different subjects. We shall select two or three of them for the sake of illustration. A card with a jockey on one side and a horse on the other, on spinning round presented the combined figure; upon tightening the string, in the manner we have described, the card changed its axis, without the slightest halt or hesitation in its rotation, and the rider was in an instant canted over the head of his charger; in a moment, however, he appeared remounted; after which, by pulling the string, with different degrees of force, he was made to stand on the saddle, and to exhibit a number of different movements. The figure of an Indian juggler was represented in the act of throwing up _two_ balls; on spinning the card, and, at the same time, altering the position of the circle, in the manner already described, _three_, and afterwards _four_, became visible. When the card revolved upon its original axis, two of the balls on the reverse side coincided with the two painted on the front, so that during the revolution they fell upon the same spot on the retina, and therefore produced a single impression; but as soon as the position of the card was changed, these spots were brought upon different points, and consequently produced separate and independent images. By alternately tightening and relaxing the strings, the balls were seen in motion, arising from and falling into the hand of the juggler.