ON GEOLOGICAL TIME. 17 



theory of energy teaches, that if there is resistance 

 of any kind (against the tidal motion of the waters, 

 for instance), that resistance must react upon some 

 body, and take from that body, or from bodies 

 connected with the phenomena, energy. 



6. The cause of the tides, as every one knows, 

 of course, is the attraction of the moon and sun. 

 The fact that the moon attracts the portion of 

 the sea nearest to her more than she attracts the 

 centre of the earth, and the centre of the earth 

 than the remote parts of the ocean, gives rise to a 

 tendency to draw water towards the moon, and 

 leave a protuberance on the other side from the 

 moon. That is the tendency ; but the water of 

 the ocean never gets time to take the exact form 

 to which it tends. Just as if a large bath were 

 suddenly tilted up and let down again : the water in 

 it, at the time it was tilted up, tended to alter it- 

 self according to the new position of the bath, but 

 there was no time for that tendency to have static 

 effect ; so it is for the waters of the ocean when the 

 moon comes to be over, for instance, the middle of 

 the Atlantic, and tends to draw the water towards 



VOL. II, C 



