If a person who is in the secret holds the cord by its two extremities, things change, since the ball, far from falling, descends very slowly along the string, or even remains stationary, and does not move again until the operator allows it to. This trick, which was formerly performed by Robert-Houdin with a ball of large size, very much surprised spectators.
How does the affair work? That is explained in the section of the magic ball shown in the [figure]. In addition to the central aperture, there is another and curved one, which ends near the extremities of the axial perforation, and a person in the secret, while making believe pass the cord through the straight aperture, actually passes it through the curved one. It will now be apparent that it is only necessary to tighten the cord more or less in order to retard or stop the descent of the ball. To the left of the engraving is seen the magic ball thus suspended between the operator’s hands.
CHAPTER V.
JUGGLERS AND ACROBATIC PERFORMANCES.
JUGGLERS.
The tricks performed by jugglers afford a most wonderful example of the perfection that our senses and organs are capable of attaining under the influence of exercise.
The juggler is obliged to give impetuses that vary infinitesimally. He must know the exact spot whither his ball will go, calculate the parabola that it will describe, and know the exact time that it will take to describe it. His eye must take in the position of three, four, or five balls that are sometimes several yards apart, and he must solve these different problems in optics, mechanics, and mathematics instantaneously, ten, fifteen, twenty times per minute, and that, too, in the least convenient position—upon the back of a running horse, upon a tight-rope, upon a ball, or upon a barrel that he causes to revolve. His dexterity is wonderful. Many jugglers are content to perform their feats of skill with their hands, and, in addition, do balancing worthy of remark.