Correspondence — Mr. G. W. LampluglK 383 



force of cm-rent to act as a powerful denuding agent. I am strongly 

 inclined to think that some fallacy lurks beneath this ingenious 

 theory in a geological point of view. In the first place, the moon's 

 action creates no currents in the open sea, the open tide being merely 

 a wave (or elevation) of translation. The water in the wave does 

 not follow the moon at all, but as soon as the moon has passed that 

 spot, falls down again. 2nd. The tidal flows and ebbs in inclosed 

 channels and seas do not denude the bounding lands into valleys and 

 gorges, but level it flat, into sand banks and mud banks. 3rd. The 

 awful rise and fall of tides of 648 feet up and down should throw 

 further doubt upon the theory, as such could only take place in the 

 open ocean far away from land. It would be quite impossible in 

 our narrow seas, where the water would not be deep enough for it. 

 4th. A wave of water cannot be conceived to travel over land like 

 a gale or hurricane, as it would collapse at once when brought into 

 shallows of its own depth from the open sea. 5th. As these waves 

 of translation must have corresponding troughs of water to draw 

 upon, where could they get them, except in the open oceans, cer- 

 tainly not in coast seas ? 6th. Therefore the disruptive and denuding 

 agency expected from such tides on the dry land of continents, I 

 beg to suggest would be illusory, and impossible of achievement. 

 The student of Geology will do better to adhere to the principles of 

 Geology taught by Sir C. Lyell, than put faith in Professor Ball's 

 theory of tidal deluges repeated every day and tearing up diurnally 

 the surface of the globe. Festina lenxe. 



THE BEIDLINGTON CRAG. 



Sir, — As my paper on the Bridlington and Diralington shell-beds 

 was meant to be descriptive, I did not think it necessary to lay 

 particular stress on the evidence which caused me to doubt Mr. S. 

 V.Wood's assertion that "the Bridlington shells unquestionably 

 lived where they occur," and I contented myself with showing that 

 " the most perfect preservation " of the shells, on which it seemed 

 to me that Mr. Wood had mainly relied, was not certain evidence ; 

 and I thought the general account given of the beds would have 

 proved the rest. Since, however, Mr. Wood has drawn attention to 

 the matter, it will perhaps be as well to group the facts which 

 caused me to differ from him. 



My reasons for thinking that the shelly patches in the Basement 

 Boulder-clay are not in place, but have been transported, are briefly 

 as follows : — 1. Neither at Bridlington nor at Dimlington do they 

 show any signs of extension or regularity ; at both places they 

 exhibit the same mixture of remnants ; and the patches — composed 

 of many kinds of sand, gravel, silt and clay, some with shells of one 

 kind, some of another, many with none — all, so far as I have seen, 

 occur at random in the clay, like boulders. 2. Most of the patches 

 are made up of material which I do not think could have been 

 obtained on this coast at that time. Coarse grains of greenish quartz 

 form much of the sand, whilst the fine blue clays have, I think, been 

 made up, in great part, of the waste of soft Neocomian beds. There 



