2 THE OCEAN WORLD. 



thousand five hundred fathoms. It is true that a great number of 

 deep-sea soundings fall short of that limit ; hut, on the other hand, 

 many others reach seven or eight thousand. Admitting that three 

 thousand fathoms represents the mean depth of the ocean, Sir John 

 Herschel finds that the volume of its waters would exceed three 

 thousand two hundred and seventy-nine million cubic yards. 



This vast volume of water is divided by geographers into five great 

 oceans : the Arctic, the Atlantic, Indian, Pacific, and Antarctic Oceans. 



The Arctic Ocean extends from the Pole to the Polar Circle ; it is 

 situated between Asia, Europe, and America. 



The Atlantic Ocean commences at the Polar Circle and reaches 

 Cape Horn. It is situated between America, Europe, and Africa, a 

 length of about nine thousand miles, with a mean breadth of two 

 thousand seven hundred, covering a surface of about twenty-five 

 million square miles, placed between the Old World and the New. 

 Beyond the Cape of Storms, as Cape Horn may be truly called, it is 

 only separated by an imaginary line from the vast seas of the south, 

 in which the waves, which are the principal source of tides, have their 

 birth. Here, according to Maury, the young tidal wave, rising in the 

 circumpolar seas of the south, and obedient to the sun and moon, rolls 

 on to the Atlantic, and in twelve hours after passing the parallel of 

 Cape Horn is found pouring its flood into the Bay of Fundy, whence 

 it is projected in great waves across the Atlantic and round the globe, 

 sweeping along its shores and penetrating its gulfs and estuaries, 

 rising and falling in the open sea two or three feet, but along the 

 shore having a range of ten or twelve feet. Sometimes, as at Fundy 

 on the American coast ; at Brest on the French coast ; and Milford 

 Haven, and the mouth of the Severn in the Bristol Channel, rising 

 and falling thirty or forty feet, " impetuously rushing against the 

 shores, but gently stopping at a given line, and flowing back to its 

 place when the word goes forth, f Thus far shalt thou go, and no 

 farther.' That which no human power can repel, returns at its 

 appointed time so regularly and surely, that the hour of its approach 

 and the measure of its mass may be predicted with unerring certainty 

 centuries beforehand." 



The Indian Ocean is bounded on the north by Asia, on the west 

 by Africa, on the east by the peninsula of Molucca, the Sunda Isles, 

 and Australia. 



