4 
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 he truly called, it is 
only separated by an imaginary lino from the vast seas of the south, 
hi which the W'aves, 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 
Gape Horn is found pouring its flood into the Bay of Eundy, 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 tailing in the open sea two or three feet, hut along the 
shore having a range of ten or twelve feet. Sometimes, as at Eundy 
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, hut gently stopping at a given line, and flowing hack to its 
place when the word goes forth, ‘ 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, sometimes called Oceania, is hounded on the 
north by Asia, on the west by Africa,, on the east by the peninsula of 
Molucca, the Sunda Isles, and Australia. 
