60 



of the River Stour in forming its deposit, holds good also with 

 respect to the other rivers in Kent, and will apply to the Rother, 

 which formerly flowed out at Romney. 



But it will be necessar}' now to consider the effect of tides in 

 the ocean as affecting our coast, and consequently the rivers* 

 mouths. Confining our attention for the present to the neigh- 

 bourhood under our consideration, we find, first, the tidal current 

 along the shore runs, on the average, with greater velocity from 

 west to east than in the contrary direction. The effect of the 

 waves on the shore is constantly that of lifting up the sand and 

 beach, and letting it fall again. If the direction of the current 

 is greatest from east to west, we should find the beach travel in 

 that direction ; but we find that from Dover to Sandwich the 

 beach travels from west to east. The waters of the Stour which, 

 we will suppose, flowed out at Sandwich in former times, would 

 thus constantly have a barrier growing from the west in the 

 shape of shingle and sand ; this would turn the mouth eastward, 

 and it has had that effect, so that at present the river beyond 

 Sandwich turns at right angles and flows towards Pegwell Bay. 

 All references to old maps and descriptions of this part of the 

 coast point to the same end. It would be going beyond the space 

 allowed for this paper to enquire how this eastward current is 

 brought about. But I would observe that the waters of the 

 Straits of Dover must, before the Straits of Dover and Boulogne 

 were so wide as at present, or rather before the land on either 

 side had been so far cut back by the long-continued wearing of 

 the sea's action, have presented a narrower channel for the exit 

 of the rising tide by the Atlantic Sea. We must remember also 

 that at a remote period — though geologically speaking, recent 

 period — England was united to France ; and also that the North 

 Sea had, for its greater portion, been dry land. A large shoal, 

 known as " The Dogger Bank," exists in the North Sea, which 

 is now, at low water, very shallow, and the dredgermen bring up 

 from it evidences that, at no very remote period, it had been dry 

 land. Bearing these facts in mind, we see that a gradual widen- 

 ing of the Straits of Dover and a deepening of the North Sea 

 at the same time must have brought about great changes 

 in the width, velocity, and direction of currents produced by 

 the tides. At the present time a north or north-east wind has 

 a marked influence in heightening the tide in the Straits of 

 Dover. We have only to refer to a tide table for our Kentish 

 coast to see that there is a marked difference in the times of high 

 water at, for instance, Whitstable and Deal. Now, if we imagine 

 the tide flowing up Channel ofi" Dover, it will have to travel 

 round the Isle of Thanet before reaching Whitstable. The dis- 

 tance it has to travel will have a retarding effect on its height, as 

 I before explained when treating of the rivers. The tide is 

 caused, as you know, by the attractive influence of the moon and 

 sun, and the diurnal revolution of the earth upon its axis will 

 •cause the maximum elevation of the tide-wave to travel ; and if 



