THE RHYTHM OF MOTION. 263 



decrease, due to the alternate coincidence and antagonism 

 of the solar and lunar attractions. We have again that 

 which is perpetually furnished by the surface of the sea: 

 every large wave bearing smaller ones on its sides, and these 

 still smaller ones; with the result that each flake of foam, 

 along with the portion of water bearing it, undergoes minor 

 ascents and descents of several orders while it is being raised 

 and lowered by the greater billows. A quite different and 

 very interesting example of compound rhythm, occurs in 

 the little rills which, at low tide, run over the sand out of the 

 shingle banks above. Where the channel of one of these is 

 narrow, and the stream runs strongly, the sand at the bot- 

 tom is raised into a series of ridges corresponding to the rip- 

 ple of the water. On watching for a short time, it will be 

 seen that these ridges are being raised higher and the ripple 

 growing stronger; until at length, the action becoming vio- 

 lent, the whole series of ridges is suddenly swept away, the 

 stream runs smoothly, and the process commences afresh. 

 Instances of still more complex rhythms might be added; 

 but they will come more appropriately in connexion with 

 the several kinds of cosmical changes, hereafter to be dealt 

 with. 



From the ensemble of the facts as above set forth, it will 

 be seen that rhythm results wherever there is a conflict of 

 forces not in equilibrium. If the antagonist forces at any 

 point are balanced, there is rest; and in the absence of mo- 

 tion there can of course be no rhythm. But if instead of a 

 balance there is an excess of force in one direction — if, as 

 necessarily follows, motion is set up in that direction ; then 

 for that motion to continue uniformly in that direction, it 

 is requisite that the moving matter should, notwithstanding 

 its unceasing change of place, present unchanging relations 

 to the sources of force by which its motion is produced and 

 opposed. This however is impossible. Every further trans- 

 fer through space must alter the ratio between the forces 

 concerned — must increase or decrease the predominance of 



