TRANSACTIONS OF SECTION J. 485 



gravel and heavy sand only travel in shallow water, but the 

 finer the sand the deeper the water it may travel in. On 

 the coast of this Island both tidal and wave currents combine 

 to carry the material of the beaches towards the north. 



On the east coast the prevailing currents from the Antarc- 

 tic Sea sweep up the coast until they reach the neighbourhood 

 of Poverty Bay, where, meeting the tropical currents driven 

 by the influence of the trade winds southwards, they pa^ss 

 away to the eastward. On the west coast the prevailing 

 northerly currents are a sort of gulf-stream from the tropical 

 currents which, flowing down the east coast of Australia, are 

 turned round by the Antarctic, and eddy back to the north 

 along the west coast of both Islands of New Zealand. This 

 accounts for the genial climate of the west coast of the South 

 Island, on which the sea has a temperature of 8° to 10° warmer 

 than on the east coast. 



From many observations I am convinced that if the waves 

 strike the coast in an oblique direction they create a current 

 in the same direction ; this current keeps close to the shore, 

 and usually only extends a few hundred yards beyond the 

 breakers. Where a great stretch of coast is under the influence 

 of such oblique waves, the current they create flows along the 

 coast regardless of the opposing direction of headlands or deep 

 bays ; a cape may project at right angles or in any direction to 

 the general coast-line, and the current will sweep round it with 

 undiminished strength. Deep bays also fail to influence the 

 current, but on the contrary the form of bays is generally 

 modified, where such currents prevail, into long sweeping 

 curves. It is in the progress of these modifications that deeply- 

 indented inlets containing rivers, or into which the current 

 cannot enter, are enclosed by boulder-banks, or spits of sand, 

 and the rougher outlines corrected to a uniform curved 

 shore. 



I have made many observations which go to prove the 

 •existence of such currents, and the consequent travel of beaches 

 continually in one direction. 



On the beach at Greymouth, a verj- moderate surf striking 

 the beach at an angle of about 20^ from the perpendicular, on 

 wading up to the breast in the sea it is found impossible to 

 keep your feet against the cui-rent flowing towards the north, 

 and at the breakwater it flows out to the end of the stonework 

 directly against the waves. Also at Westport, in moderate 

 Aveather, with the waves from west-south-west, a powerful 

 current sweeps round the end of the breakwater towards the 

 north. A ship stranded near Cape Foulwind was carried by 

 the current, bumping along the beach, into the Builer Eiver 

 mouth. A piece of ship's hawser thrown into the sea at 

 Hokitika is picked up on the Greymouth side of the Teremakau, 



