“Now I understand it,” cried Tom; “instead of the weight supporting the horse, the horse supports the weight.”
“Exactly so. You perceive, therefore, from these few examples, that the balancer, by availing himself of such deceptions, and combining with them a considerable degree of manual dexterity, may perform feats, which, at first sight, will appear in direct opposition to the laws of gravity. There is also another expedient of which the balancer avails himself, to increase the wonder of his performances, and that is the influence of rotatory motion, which, you will presently see, may be made to counteract the force of gravity.”
“I remember that the most surprising of all the tricks I witnessed was one, in which a sword was suspended on a key, which turned round on the end of a tobacco-pipe; on the top of the sword a pewter-plate was, at the same time, made to revolve with great velocity.”
“I well remember the trick to which you allude. The rotatory motion prevented the sword from falling, just as you will hereafter find the spinning of the top will preserve it in an erect position. There is also another effect produced by rotatory motion, with which it is essential that you should become acquainted. You, no doubt, remember that momentum, or the velocity of a body, will compensate for its want of matter. A number of bodies, therefore, although incapable of balancing each other when in a state of rest, may be made to do so, by imparting to them different degrees of motion. I believe that you are now acquainted with all the principles upon which the art of balancing depends; and I have little doubt, should we again witness a performance of this kind, that you will be able to explain the tricks which formerly appeared to you so miraculous.”
[9]. In Scotland stilts are used to pass rivers.
[10]. A The vicar here alludes to the speech of Moloch (Paradise Lost, b. ii. 1. 75):--
“That in our proper motion we ascend
Up to our native seat: descent and fall