192 Correspondence — Mr. A. R. Hunt — Miscellaneous. 



The English Channel is an excellent test case. It is shallow and 

 opens full into the Atlantic Ocean. It lies east and west, and accord- 

 ingly offers no impediment to the free play of the currents generated 

 by the tidal wave which runs from east to west. 



If unchecked tidal currents are anywhere resistless, they should 

 be so here. Do these tidal currents disturb the gravel, or sand or 

 even the mud on the Channel bottom ? The marine fauna of the 

 district answers this question with an emphatic negative. 



It is generally admitted that very few molluscs can exist in an 

 area of shifting sand, and the denizens of the Channel bottom are 

 not of the number. They are, it is true, wonderfully provided 

 with diverse defences against currents of a peculiar nature, viz. the 

 alternating currents set up by waves ; but even these must not be 

 too violent, or the molluscs will perish by the million, as indeed 

 they often do from this cause alone. 



Geologists interested in the question of denudation and distribution 

 by tides and waves will be familiar with Delesse's " Lithologie du 

 Fond des Mers," and the admirable atlas accompanying that volume. 

 If they will turn to Map 2, they will note that the area of the 

 English Channel most frequented by shells extends from west of 

 the Land's End to Ushant, and up the centre of the Channel to a 

 point off Exmouth ; with another large sandy area of shells west of 

 Ushant. These are precisely the localities where we might expect 

 the tidal currents to make a clean sweep of the Channel bottom, but 

 nothing of the sort occurs. The presence of this Molluscan fauna 

 in these very exposed localities is good proof that unchecked tidal 

 currents sweeping over a fairly level sea-bottom are incapable by 

 their own unassisted efforts of raising the sand ; a glance at the map 

 will show that they cannot even wash away the mud. 



This being my special craze, and having noted observations and 

 experiments thereon for many years, on shore and afloat, I could 

 fortify my position at such length as would insure this letter finding 

 a place in the editorial waste-paper basket, so I refrain. 



One word in conclusion — would Mr. Mellard Reade give his 

 reasons for believing "that waves ever cause surface particles in deep 

 water to move in " an ellipse, not very different from one having 

 the longer axis vertical " ? I have heard this stated by a lecturer, 

 who drew a vertical ellipse on the blackboard like the long eye of 

 a bodkin ; but I have never seen the statement in print except in 

 Mr. Mellard Eeade's paper above referred to (p. 338). 



Soutitwood, Torquay. Arthur E. Hunt, F.L.S. 



MISCELLAUEOTJS. 

 The Discovery of Coal at Shakespere's Cliff. — In February 

 last Prof. W. Boyd Dawkins, F.R.S., announced that Coal had been reached in the 

 experimental boring near Dover. A seam of coal of good bituminous character was 

 reached at 1180 feet from the surface, 3 feet 6 inches in thickness, with a 4 inch 

 parting of shale and sandstone in the middle. 1 The boring is to be continued for 

 another 1000 feet, if necessary, to ascertain whether other beds of workable coal 

 exist at a lower level. 



1 An oil-shale is also mentioned. 



