498 EQUILIBRATION. 



Every motion being motion under resistance, is continually 

 suffering deductions; and these unceasing deductions finally 

 result in the cessation of the motion. 



The general truth thus illustrated under its simplest 

 aspect, we must now look at under those more complex 

 aspects it usually presents throughout Nature. In nearly all 

 cases, the motion of an aggregate is compound; and the 

 equilibration of each of its components, being carried on in- 

 dependently, does not affect the rest. The ship's bell that 

 has ceased to vibrate, still continues those vertical and lateral 

 oscillations caused by the ocean-swell. The water of the 

 smooth stream on whose surface have died away the undu- 

 lations caused by the rising fish, moves as fast as before 

 onward to the sea. The arrested bullet travels with un- 

 diminished speed round the Earth's axis. And were the 

 rptation of the Earth destroyed, there would not be implied 

 any diminution of the Earth's movement with respect to the 

 Sun and other external bodies. So that in every case, what 

 we regard as equilibration is a disappearance of some one or 

 more of the many movements which a body possesses, while 

 its other movements continue as before. That this 



process may be duly realized and the state of things towards 

 which it tends fully understood, it will be well here to cite a 

 case in which we may watch this successive equilibration of 

 combined movements more completely than we can do in 

 those above instanced. Our end will best be served, not by 

 the most imposing, but by the most familiar example. Let 

 us take that of the spinning top. When the string which 

 has been wrapped round a top's axis is violently drawn off, 

 and the top falls on to the table, it usually happens that be- 

 sides the rapid rotation, two other movements are given to it. 

 A slight horizontal momentum, unavoidably impressed on 

 it when leaving the handle, carries it away bodily from the 

 place on which it drops ; and in consequence of its axis being 

 more or less inclined, it falls into a certain oscillation, 

 described by the expressive though inelegant word 



