112 THE OCEAN. [Book IV, 



in advance in the orbital motion, and the counter- tide 



on the opposite side, would, whilst keeping their 

 positions unchanged in respect to the forces by 

 which they are raised, appear to have cyclonic move- 

 ments, for they would (even if their course were due 

 west) alternately rise and fall towards and from the 

 equator along each meridian just as much as east and 

 west along each parallel of latitude. 



The tide, though travelling round the earth from 

 east to west, would commence on any meridian in 

 high latitudes in the form of an undulation rising 

 from the west, and would then converge along the 

 meridian towards the equatorial regions where the 

 undulation would be from the east, so having the 

 apparent motion of a cyclone on each side of the 

 equator : for, as already shown, the tide is in a chronic 

 state of trymg to place itself on the meridian on 

 which the luni- solar force tends to raise it ; but, as 

 the earth's rotation as constantly prevents it from 

 achieving this, it is for ever rising towards it from 

 the west in high latitudes, and from the east along 

 the equator, being upon it only in the intermediate 

 latitude, in which its normal velocity is the same as 

 that with which the latitude rotates. 



Thus it is evident from the foregoing that, though 

 the whole tide travels westwards, not only have the 

 tidal undulations movements in opposite directions 

 in the temperate and equatorial regions, but, besides 

 this, recorded times of high water would show a 



