^^ THE OCEAJS". 



neiglibourhood of submarine banks ; also those "ground swells" which 

 suddenly raise the surface of the sea and endanger boats; and those 

 formidable tide-races which springing from the depths of the ocean 

 advance abruptly upon its sloping beaches, destroying all they en- 

 counter on their way. 



It is along the shores of continents and around rocky islands that 

 ordmary waves and heavy surf appear in all their grandeur and 

 assume dimensions truly formidable. In accordance with the more 

 or less gradual inclination of the bottom to the shore, a wave coming 

 Irom the open sea rolls over a bed more and more shallow, and must 

 perforce slacken its speed ; but at the same time it increases by its 

 o^vn depth the stratum of water which it overflows, and consequently 

 the wave which follows it is subjected to less retardation of the im- 

 pulsive force. The second wave constantly gains on the first, and 

 iinally reaches it, swelling its crest, and slackening its own speed in 

 Its turn, gives a third wave time to distance it also. Finally, near 

 the strand, the liquid mass, swelled by the pursuing waves, and unable 

 to spread out further at its base along the shore which is too near • 

 It gams m height what it wants in breadth, and rising like a wall' 

 It bends over with a wide curve in front, and breaks with a thunder- 

 ing sound, throwing water mixed with sand and foam far along the 

 shore This surge, which is dreadful indeed during tempests, rises 

 much higher than the waves; to the ancients the whitening billows 

 ot the open sea, whose crests were seen to shine like the fleeces of 

 sheep, were the flocks of Proteus ; while the waves of the shore, still 

 called m our days camlli and cataUoni by the people of the south of 

 -burope, were the foaming horses of Neptune. 



The height to which the crests of some of these waves attain when 

 the configuration of the coast favours the movement, seems sometimes 

 o partake of the marvellous. The mass of water which rises ver- 

 tically can then only be compared to an ascending cataract. Spal- 

 lanzani relates that sometimes, in violent tempests, the waves reach 

 half-way up, or even to the top, of Stromboluzzo, a peak of lava which 

 rises near Stromboli 318 feet above the mean level of the sea. The 

 1 ^t ^^^g^t^.^f ^^ which rises boldly to 112 feet in height on a 

 rock off the Scottish coast, is often enveloped in waves and foam even 

 long after the tempest has ceased to disturb i\^^ sea.* Smeaton, too 

 has seen waves covering the Eddystone lighthouse, and leaping in a 

 spout o water 82 i..i above the lantern ; the mass which is thus raised 

 around the edifice cannot be less than from 2616 to 3924 cubic yards, 



*:.Irs. SoiuerviUe, Thysical Geography. 



