THE TIDES/ 



1. Th eir correspondence with the lunar phases known at an early period. 

 2. Erroneous notions prevalent as to their causes. 3. Not caused by 

 the moon's attraction. 4. But by the inequality of its attraction. 

 5. Calculation of this inequality. 6, Solar tides. 7. Difference 

 between the power of the sun and moon to produce a tide. 8. Spring 

 and neap tides. 9. Why the tides are not directly under the moon. 

 10. Establishment of the port. 11. Effects of the form of the coasts 

 upon the local tides. 12. Dr. WhewelFs analysis of the progress of 

 the tidal wave. 13. Age of the tide. 14. Velocity of the tide. 

 15. Undulations. 16. Motion of the crest of a wave. 17. Range of 

 the tide. 18. How affected by the weather. 



1. THE phenomena of the tides of the ocean are too remarkable 

 and too important to the social and commercial interests of man- 

 kind, not to have attracted notice at an early period in the progress 

 of knowledge. The intervals between the epochs of high and low 

 water everywhere corresponding with the intervals between the 

 passage of the moon over the meridian above and below the 

 horizon, suggested naturally some physical connexion between 

 these two phenomena, and indicated the probability of the cause 

 of the tides being found in the motion of the moon. 



Kepler developed this idea, and demonstrated the close con- 

 nexion, of the phenomena ; but it was not until the theory of 



LARDNER'S MUSEUM OP SCIENCE. 



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