346 E. M. KINDLE 



bottom. The only mud-bank of considerable volume is that formed by the 

 sediment which the St. John River carried to the sea. It begins at the harbor 

 of St. John and extends westward along the coast as far as the small islands 

 called The Wolves, its outer limit coinciding nearly with the fifty fathom 



line As a rule where the movement of the current exceeds one and a 



half knots mud is not deposited on the bottom of the bay. 



Current work in deep water. — It must be pointed out that non- 

 deposition and scour is not confined to shallow and narrow sea 

 ways. Ocean currents are known to sweep the sea floor at con- 

 siderable depths and at considerable distances from land. At 

 the head of the Bay of Bengal the great delta deposits of the Ganges 

 and Brahmaputra rivers are interrupted by a deep channel called 

 the ''Swatch of no ground" which is kept open presumably by 

 some acceleration of the tidal currents. This channel which 

 has a depth of 200 to 300 fathoms terminates abruptly on the west 

 side in water only 5 to 10 fathoms deep.^ Thus we have in the 

 midst of an area in front of the mouths of the two greatest rivers 

 of India where sedimentation proceeds with great rapidity a belt 

 of sea bottom where deposition is supplanted by scour. 



Off the west coast of Scotland tidal currents of great strength 

 are known at some points to sweep the bottom at a depth of nearly 

 100 fathoms. Between Glas Island and Sgeir-i-Noe in the Little 

 Minch off the west coast of Scotland the flood-stream often takes 

 the buoys of the long lines down "and it is a remarkable circum- 

 stance, indicative of the great depth of the tidal-stream here, 

 that the buoys though anchored in 70 or 80 fathoms are taken 

 completely to the bottom; starfish and other marine animals 

 being found attached to them."^ 



The laying of the transatlantic cables brought to Hght evidence 

 of powerful currents at unexpected depths. 



Perhaps the most marked experience we have had of currents at great 

 depths was in the case of the Falmouth cable near Giberaltar. At 500 fathoms 

 the wire was ground like the edge of a razor and we had to abandon it and 

 lay a cable well inshore. Captain Nares, of the surveying ship Nemesis, I 



'James Ferguson, Quart. Jour. Geol. Soc, XIX (London, 1863). 



^ Sailing Directions for the West Coast and Islands of Scotland from the Mull of 

 Cantyre to Cape Wrath, p. 119. 



