250 Scientific Proceedings, Royal Dublin Society, . 



both ways ; whereas the piece of laminaria, though rolled back- 

 wards, was light enough to be lifted forwards. 



(4). The foregoing observations having been made, the tide, 

 having in the meantime covered the flat sands, had reached a slop- 

 ing beach. Thrusting a razor shell [solen) into the sand of this 

 beach for a mark, I watched the action of the waves on a stone 

 lying on the slope. It gradually worked its way up the rather 

 steep incline, notwithstanding the fact already referred to, that the 

 water-soaked stick had travelled seawards down one whose gradient 

 was much less. 



Experiment. — Sept. 30, 1882. — In front of a small sloping 

 sand-beach, in my experimental tank, I placed a large slate, care- 

 fully levelled with a spirit-level. The slate was then covered' with 

 water to the depth of about one inch, so that the waves produced 

 by my wave-generator might break heavily on it. I found that 

 marbles placed on the slate evinced a decided tendency to travel 

 outwards against the 'waves, but that fragments of crushed granite 

 were washed shore wards. Once only was a piece of granite washed 

 off the slate. 



(5). Oct. 3, 1882. — Walked from south end of Goodrington 

 sands (Torbay) to north-east end. of HoUowcombe sands. Tide 

 ebbing. Came to the conclusion that when the waves do not break, 

 the combined action of the inward and outward currents washed 

 objects on the bottom outwards, but that breakers carried forwards 

 whatever they could lift. 



(6). Oct. 4, 1882. — Beach east of raised beach at Hope's Nose. 

 Tide (neaps) ebbing. Waves inclined to roll stones up the sand- 

 slope. Sand softish and coarse ; seemed to offer much resistance 

 to descent of the stones. One rounded flint, the size of an e^g, 

 was driven up several times. 



The breakers were most decided in their upward action ; but 

 even the wash backwards and forwards showed no tendency towards 

 downward propulsion. (N.B. — This conflicts with Observation (5) ). 



