Hunt— Ow the Action of Waves on 8ea-beaches, 8fc. . 277 



In OUT consideration hitherto of the action of waves running 

 on to beaches at rightangles to their trend, we have noticed the 

 various effects produced by swells of different sizes and characters 

 on beach-material of different size, form, and specific gravity ; and 

 have seen how greatly the distribution of the beach-material by 

 the waves is affected by the tidal variation in the sea-level. It 

 would seem that ordinary waves, acting on mixed beach-material 

 on a tidal strand, would be sufficient of themselves to form the 

 peculiar beaches described by Mr. Price, where the high-water 

 ridges are separated from large stones lower down by zones of peb- 

 bles, gravel, and coarse sand. — (See R., 57.) 



In the ordinary case of waves rolling on a beach under the in- 

 fluence of wind, the action of the wave-currents are complicated by 

 currents set up by the wind-pressure on the surface of the water. 

 It is impossible to overrate the importance of the latter currents, as 

 they frequently overpower and obliterate the normal tidal currents 

 of the locality. Prof. J. D. Dana says, that " the forcing of water 

 into bays, whether by regular winds or by storms, causes a strong 

 under-current outward, like that from the tides. This happens 

 when the entrance of the bay is broad, so as to allow of an in-flow 



over a wide area, while the deep-water channel is narrow " — 



{Man. GeoL, 3 ed., p. 671.) It will be easy to show that under 

 other circumstances the result will be different. Prima facie it is 

 probable that the surface-water will leave the bay at the point, or 

 points, where it will encounter least resistance, whether at the sides 

 or centre, at the bottom or surface, or at two or more of these 

 together. The following instances in the case of Torbay are in- 

 structive : — 



On January 7th, 1883, during a strong S. W. gale, I found 

 that there was a strong inward surface- current in the mouth of 

 Torquay Harbour (tidal), although the tide was half -ebb. Feeling 

 sure that under the circumstances there must be a strong under- 

 current outwards, I tied stones to a couple of net-corks, with strings 

 about six and eight feet long respectively. On these being thrown 

 into the water, the corks were carried seaward in the teeth of the 

 gale, though in squalls it was blowing furiously. The stones, 

 though small enough not to submerge the corks, offered sufficient 

 resistance to the outgoing under-current to tow the corks out of 



