THE EARTH. 255 



vity. Over these, the waters of the tide steal by 

 almost imperceptible degrees, covering them for 

 a large extent, and leaving them bare on its re- 

 cess. Upon these shores, as was said, the sea 

 seldom beats with any great violence, as a large 

 wave has not depth sufficient to float it onwards ; 

 so that here only are to be seen gentle surges 

 making calmly towards land, and lessening as 

 they approach. As the sea, in the former des- 

 cription, is generally seen to present prospects of 

 tumult and uproar, here it more usually exhibits 

 a scene of repose and tranquil beauty. Its wa- 

 ters, which, when surveyed from the precipice, 

 afforded a muddy greenish hue, arising from their 

 depth and position to the eye,* when regarded 

 from the shelving shore, wear the colour of the 

 sky, and seem rising to meet it. The deafen- 

 ing noise of the deep sea is here converted into 

 gentle murmurs ; instead of the water dashing 

 against the face of the rock, it advances and re- 

 cedes, still going forward, but with just force 

 enough to push its weeds and shells, by insen- 

 sible approaches, to the shore. 



There are other shores, besides those already 

 described, which either have been raised by art, 

 to oppose the sea's approaches, or, from the sea's 

 gaining ground, are threatened with imminent 

 destruction. The sea's being thus seen to give 

 and take away lands at pleasure, is, without ques- 

 tion, one of the most extraordinary considerations 

 in all natural history. In some places it is seen 



* Newton's Optics, p. 163 167. 



