THE TIDES. 163 



senting a water envelope surrounding- the earth. 

 There has been much discussion on the origin 

 of the word neap. It seems to be an Anglo-Saxon 

 word meaning scanty. Spring seems to be the 

 same as when we speak of plants springing up. 

 I well remember at the meeting of the British 

 Association at Edinburgh a French member who, 

 meaning spring tides, spoke of the grandes marees 

 die printemps. Now you laugh at this ; and yet, 

 though he did not mean it, he was quite right, 

 for the spring tides in the spring time are greater 

 on the whole than those at other times, and we 

 have the greatest spring tides in the spring of 

 the year. But there the analogy ceases, for we 

 have also very high spring tides in autumn. Still 

 the meaning of the two words is the same etymo- 

 logically. Neap tides are scanty tides, and spring 

 tides are tides which spring up to remarkably 

 great heights. 



The equilibrium theory of the tides is a way 

 of putting tidal phenomena. We say the tides 

 would be so and so if the water took the figure 

 of equilibrium. Now the water does not cover 



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