THE BORE. 233 



est tides. The Bore whfch enters the river Severn is sometimes 

 nine feet high, and at spring tides rushes up the estuary with ex- 

 traordinary rapidity. In the Hoogly or Calcutta river, says Ren- 

 nell, " the Bore commences at Hoogly point, the place where the 

 river first contracts itself, and is perceptihle above Hoogly town; 

 and so quick is its motion, that it hardly employs four hours in 

 traveling from one to the other, though the distance is nearly 

 seventy miles. The tides of the Bay of Fundy pour twice a day 

 vast bodies of water through a narrow strait, causing in every 

 small stream, an immense tidal wave, rising sometimes to the 

 height of seventy feet. We have already alluded to its rich 

 alluvial deposits of red marl which have been excluded artificially 

 from the sea by embankments. 



Heretofore we have noticed only the degrading effects of cur- 

 rents, and tides. It might at first appear that the sediment borne 

 down by rivers, the formation of deltas, and the silting up of 

 estuaries, would compensate for the loss by the encroachments of 

 the sea, this however, is not the case; while in all instances the 

 new-made land is constantly attracting attention, there are no 

 boundaries, or great natural land marks, to show where was 

 formerly the line of coast. The former demand attention by 

 their presence, the latter are unseen, and therefore lightly esti- 

 mated; many places where once flourishing cities stood, are now, 

 not only depopulated, but covered with water to a depth of thirty 

 feet. There is therefore good reason for believing that the loss 

 of land by the effects of currents and tides, much more than 

 counterbalances all deposited in the form of dry land. 



The general tendency of these encroachments is undoubtedly 

 to fill up the bed of the sea, and to finally reduce the surface of 

 the earth to a uniform level ; and this would ultimt.teh be ac- 

 complished, but for the counterbalancing force of volcanic or ig- 

 neous causes, which are continually elevating the surface. If 

 we had space we might continue to enumerate examples of the 

 effects of the ocean in destroying the coasts, not only of our own 

 country, but over the whole world : sufficient however has been 

 said to give some idea of the importance of these causes of change, 

 and when hereafter, we allude to immense formations of rock 



