SWIRLS OF THE SEA 



33 



gers — has been held responsible for many a 

 sad sea-tale due to human carelessness; but the 

 ordinary tide is quite harmless and floods in as 

 softly as the moonlight over sunset prairies. 



This, however, cannot always be said about 

 the most violent of the tidal manifestations as 

 seen in the mouths of certain rivers. A 

 " bore " is not only fascinating but it may 

 be very dangerous to shipping. It is usually 

 caused by the inward rush of the tide water 

 opposing the slow outward movement of the 

 river water. The tide is at first driven in and 

 wedged to a great height by the narrowing 

 shores. It then encounters the river water, 

 pushes it up to a flattened angle, and finally 

 breaks over it and on it with a foam, a dash, 

 and a roar. It may take other forms from 

 other causes, but it is usually a breaker, not 

 dashing up the beach, but dashing up the river 

 mouth over the water of the river. Sometimes, 

 as at the final exit of the Colorado, this breaker 

 comes forward with great power. At the mouth 

 of the Amazon it reaches a height of sixteen 

 feet (it is said to be even higher) and the bores 

 of the Tsien-Tang-Kiang and the Ganges arc 

 hoth famous and dreaded. For the breaker 

 whether upon the bay or upon the coast has a 

 crushing blow that ribs of steel and walls of 



The 

 "bore." 



"Bores" of 

 the Colorado 

 and the, 

 Amazon. 



