120 THE OCEAN. 



the Blanchard Eace, of a rapid movement of the waters tending al- 

 ternately in one or the other direction, at the time of the change of 

 the tides. When in the open sea the flow rises in the direction from south 

 to north, a part of its mass spreads with force into the strait opening to 

 the south, between the tv/o islands of Moskoe and Moskoe-naes. In 

 proportion as the surface approaches a state of equilibrium, the cur- 

 rent, gradually weakened, tends towards the south-west and then to 

 the west. A period of calm follows these different movements of the 

 waves, when the level is perfectly established ; but soon the ebb com- 

 mences, and tends in an inverse direction, at first towards the north, 

 then towards the north-east and east. Thus in the space of one 

 tide the waters are alternately carried, though with varying force, 

 towards all the points of the compass. 



The tidal currents, which occur at the entrance to rivers, frequently 

 give place to tumultuous movements less terrible, it is true, than those 

 of the races in archipelagos ; but sometimes of an equally striking 

 aspect. These phenomena are known under the name of the '' bore,'' 

 barre, " eager," or mascarct. 



In penetrating into the estuary of a river, the tidal wave, retarded 

 by the shallows and narrowed by its banks, must necessarily swell 

 because of the restriction of the liquid mass in its bed. All the inlets 

 and bays into which the tide penetrates present thus the spectacle of 

 the " bore ; " but in many passages the regular inclination of the bed, 

 the uniformity of the shores, or else an intersection of various currents, 

 diminish the first undulation of the tidal wave, or permit it to be 

 confused 'VN'ith other irregularities of the surface. Elsewhere, on the 

 contrary, all the topographical conditions are found united to give a 

 great height to the "bore," and it then rises like a moving wall from 

 one shore to the other of the estuary. At the mouths of certain rivers, 

 such as the Amazon, the Ilooghly, the Seine, the Dordogne, the Elbe, 

 and the Weser, the waves of the " bore " assume enormous propor- 

 tions at the time of high tides, and become formidable phenomena. 

 In the Amazon, the " bore,^' called porovoca because of the roaring of 

 its waters, rises, it is said, in .three successive waves, attaining 

 together from 30 to 50 feet in height ; and vessels, surprised by this 

 sudden flood, are in great risk of capsizing as in the open sea. 



At the mouth of the Ganges the "bore " is also very formidable. 

 As the old Hindoo legend says, in symbolic language, Bagharata 

 having taken the divine Ganga as his spouse in the midst of snows, 

 raised her in his arms, and, mounting his chariot, traced with its two 

 large wheels the banks of the wide bed of the goddess. But when 



