CENTRE OF OSCILLATION. 



vibration they will assume the positions a', b', c', d', e',f, g'. That 

 which is nearest to the point B, and which is the shortest pen- 

 dulum, will be foremost, since it has the most rapid vibration. 

 The next in length, b', will follow it, and so on ; the most remote 

 from s being the longest pendulum, g' being the last in order. 



Now if, instead of supposing these seven balls to be suspended 

 by independent strings, we imagine them to be fixed upon the 

 same wire, so as to be rendered incapable of having any inde- 

 pendent motion, and compelled to keep in the same straight line ; 

 then it is evident, that while the whole series vibrates with a 

 common motion, those which are nearest to the point of suspension 

 will have a tendency to accelerate the motion of those which are 

 more distant, while those which are more distant will have a 

 tendency to retard the motion of those which are nearer. 



These effects will produce a mutual compensation ; b and c will 

 vibrate slower than they would if they were moving freely, while 

 e and/ wiU evidently move more rapidly than if they were moving 



13 



