326 



PHYSICAL GEOGRAPHY. 



to the efforts of the Russian authorities.. But enough is known of the great world of 

 waters, of its extent, utility, and varying phenomena, 



" Calm or convuls'd, in breeze, or gale, or storm, 

 Icing the pole, or in the torrid clime 

 Dark heaving," 



to invite the eye of admiring contemplation, and enrich the mind with conceptions of 

 grandeur, beauty, and beneficence. Unstable as it appears, so as to have become a com 

 mon emblem of inconstancy with the nautical races, it has far more permanent stability 

 than the solid earth ; nor is the language of the modern poet 



" Time writes no wrinkle on thy azure brow ; 

 Such as creation's dawn beheld, thou rollest now," 



any violation of philosophical truth, for the level of the ocean, however temporarily fluc 

 tuating, appears to experience no enduring change. 



The bed of the ocean corresponds in various respects to the surface of the dry land. It 

 is luxuriantly clothed with marine vegetation in several localities, and entirely barren in 

 others. Earthquakes exert their mighty action upon it; and volcanic agenay effects 

 displacement. It is diversified also with plains, valleys, and mountains, the summits of 

 the latter often just peeping above the waves. Hence the depth of water is very various, 

 from that of the stratum which is scarcely navigable to that of the enormous mass 

 which no plummet has ever sounded. But this of course does not prove the ocean 

 to be anywhere a bottomless abyss because it is unfathomable ; it only overreaches the 

 limited extent of our sounding lines. Nor perhaps do such experiments show the approxi 

 mate depth in those places, for an under-current may have carried the lead far away 

 from a perpendicular direction. Along a low, level, and sandy shore, the sea is generally 

 shallow, but the reverse in the neighbourhood of a bold and towering coast. The 

 recession of the tide off the flats of Lincolnshire and Holland, converts large tracts into 

 dry land, while the Mediterranean, where mount Athos rises abruptly from it to the 

 height of 6000 feet, has a depth of from 500 to 600 feet close in shore. Around low 

 islands, except those of coral formation, shoals and shallows are common, often at a 

 considerable distance from the beach ; but around those which project from the bosom of 

 the ocean to a great elevation, as St. Helena, the depth frequently cannot be sounded. 



Saint Helena. 



On approaching Aurora Island, one of the Panmato group of South Sea Islands, the officers 

 of the American expedition sounded at one hundred and fifty feet from its perpendicular 

 cliff, and found no bottom at a hundred and fifty fathoms. 



