THE IMPENETRABLE SEA 



One of the most notable bores in Great Britain is the 

 one which periodically occurs on the Severn, near the 

 head of the Bristol Channel. The tide, which rises to a 

 height of forty feet, making a most impressive spectacle, 

 rushes up the funnel-shaped Channel in a continuous 

 wave ninety yards in length, and with a crest averaging 

 four or five feet. But the height of the bore's crest varies. 

 In 1932 the moving wall of water was nearly eight feet 

 high. As the bore rushes up the Severn it makes a curious 

 noise, as though it were a living thing speeding forward 

 to capture its prey. 



Bores on British rivers include a remarkable one which 

 rushes up the Trent, forming a wave from three to five 

 feet high, and others on the Solent and Dee. In France a 

 wave seven feet high races up the Seine at spring tide, to 

 a distance of forty miles up the river. Another of similar 

 height travels up the river Hooghly in India, while an 

 even higher one — twelve to fifteen feet high — appro- 

 priately called the amassona^ meaning "boat destroyer", 

 sweeps up the Amazon with a roar that can be heard 

 over five miles away. 



The world's most remarkable bore occurs on the 

 Tsien-tang-kiang in China. A tidal wave from the Pacific 

 rushes into the estuary, and as the water piles up a bore 

 is created which may be as much as thirty-four feet in 

 height. Its approach can be heard for more than an hour 

 before its arrival, and as it passes the sound has been 

 likened to the roar of Niagara Falls. It rushes by Haining 

 at a speed of over fourteen miles an hour, and it has been 

 calculated that nearly two million tons of water pass that 

 place every minute when the bore is in full spate. The 

 mighty wall of water dies away at last about forty-two 

 miles from the river's mouth. 



Although the Tsien-tang-kiang bore is rightly regarded 

 as the world's greatest, there is an area even more remark- 

 able for the great rise and fall of its tides, and for the 

 number of its bores. This is the Bay of Fundy, an inlet 



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