Springs, Rivers^ and the Sea. 139 



the moon is upon the meridian of any 

 place, it will always be found to happen, 

 as far as circumstances will allow, about 

 three hours afterwards ; and the intervals 

 between the flux and reflux, must be reck- 

 oned from that time in the same manner 

 as before. 



The sun being nearer the earth in win- 

 ter than in summer, is nearer to it in Feb- 

 ruary and October than in March and 

 September ; and therefore the greatest 

 tides happen not till some time after the 

 autumnal equinox, and return a little be- 

 fore the vernal. 



The tide propagated by the moon in the 

 German ocean, when she is three hours 

 past the meridian, takes twelve hours to 

 come from thence to London Bridge ; 

 where it arrives by the time that a new 

 tide is raised in the ocean. 



These are the principal phenomena of 

 the tides ; and where no local circumstan- 

 ces interfere, the theory and facts will he 

 found to agree. <But it must be observed 

 that what has been here said, relates only 

 to such places as lie open to large oceans. 

 In seas and channels, which are more con- 

 fined, a number of causes concur, which 



