42 
THE OCEAN WORLD. 
being twenty-four hours fifty minutes of mean time. If, for instant 
it is high water to-day at two o’clock in the morning, that of the ne^ 
day will take place at fifty minutes past two. Low water does 
occur, however, at the half of the intermediate time ; the flux is moW 
rapid than the reflux : thus at Havre, Boulogne, and at corresponding 
places on this side of the Channel, it takes two hours and eight 
minutes more in retiring ; at Brest, the difference is only sixteen minute 
more than the flux. The daily retardation of high water by the passag® 
of the moon in the meridian, at the equinoxes, is a constant quantity' 
for the same locality, which can be determined by direct observation- 
The height of the tide varies in the different regions of the glob 1 -’’ 
according to local circumstances. The eastern coast of Asia and tl > 5 
western coast of Europe are exposed to extremely high tides ; while i ' 1 
the South Sea Islands, where they are very regular, they scarcely rea^ 
the height of twenty inches. On the western coast of South America 
the tides rarely reach three yards ; on the western coast of Inch* 
they reach the height of six or seven ; and in the Gulf of Cambay 
ranges from five to six fathoms. This great difference makes itse^ 
felt in our own and adjoining countries: thus, the tide, which 
Cherbourg is seven and eight yards high, attains the height of fourteen 
yards at Saint Malo, while it reaches the height of ten yards ^ 
Swansea, at the mouth of the Bristol Channel, increasing to double 
that height at Chepstow, higher up the river. In general, the tid e 
is higher at the bottom of a gulf than at its mouth. 
The highest tide which is known occurs in the Bay of Fundy, whi^ 
opens up to the south of the isthmus uniting Nova Scotia and N<^ 
Brunswick. There the tide reaches forty, fifty, and even sixty fee*' 
while it only attains the height of seven or eight in the bay to the north 
of the same isthmus. It is related that a ship was cast ashore up 0 * 1 
a rock during the night, so high that at daybreak the crew f'oui 1 ^ 
themselves and their ship suspended iu mid-air far above the water ! 
In the Mediterranean, which only communicates with the ocean by 9 
narrow channel, the phenomena of tides is scarcely felt, and from tW] 
cause — that the moon acts at the same time upon its whole surface 
which are not sufficiently abundant to increase the swelling mass ^ 
waters formed by the moon’s attraction ; consequently, the swelli^ 
remains scarcely perceptible. This is the reason why neither tb e 
