1866.] JFKES OLD RED SANDSTOl^E AND DETOIflAN. 355 



country. Had the ravines been in any way due to internal disturb- 

 ances and dislocations (a belief which still seems to linger in the 

 minds of some geologists of eminence), why did not some of them 

 cause at least one ravine to cross the present watershed ? The rocks 

 must be as much disturbed about the watershed as anywhere else, 

 according to any hypothesis as to the internal structure of the 

 country ; but the surface is an unbroken, gently undulating, upland 

 plain or moor. 



There is one quarry on the left of the road, about a mile south-west 

 of Parracombe, near the hill- top before reaching the turnpike, which 

 showed a glossy-black slate with some dove -coloured sandstones, 

 over which were some black, earthy, carbonaceous-looking slates, 

 all dipping south at 30°. I was half inclined at first to look upon these 

 as possibly the base of the Coal-measures rolled in, as a small basin, 

 but was unable to find any fossils in them. Subsequently I saw 

 beds like the grits near Ilfracombe. 



Going down the hill into Ilfracombe I again examined the quar- 

 ries which had formerly puzzled me ; but was again baffled, and 

 unable to come to any decided opinion as to the dip of the beds. A 

 very strong cleavage dipping south at a high angle, obliterates the 

 stratification. 



"Walking to the east, however, from Ilfracombe as far as the 

 bathing place called Eapparee Cove, and thence over the hiU to 

 Helesborough, I met with rocks of unmistakeable characters. The 

 dark slates with occasional grit-bands are precisely those of Kinsale 

 Harbour, for instance, or of so many other places in County Cork. 

 These slates lie higher in the series than those in which the Coom- 

 hola grits occur. The grits they do contain are usually in single 

 beds and are unfossiliferous. The slates, too, are often unfossiliferous 

 in Ireland through a thickness of one or two thousand feet and an 

 extent of many miles. The general dip of these rocks, east of Ilfra- 

 combe, is certainly to the south, at angles varying from 30° to 60°, 

 but this dip is by no means so persistent as it at first appears. 



As it is possible that some young geologist, unaccustomed to cleavage in rocks, 

 may visit this spot, perhaps I may be pardoned for entering a little into details 

 which may serve to guide his observations. 



Keeping along the south side of the harbour towards the bathing-cove, which 

 the boatman called E-apparee Cove, he will see a hmekiln, near which there is a 

 little cavernous hole under the cliff. 



The arched roof of this little cavern nearly coincides with a curve in the beds, 

 as shown by the narrow bands, differing slightly in colour and grain (the 

 "stripe" of Professor Sedgwick), which indicate the original bedding of the 

 rock. The cleavage, however, dips steadily to the south at 66° (see fig. 13). 



A still more striking example presents itself in Eapparee Cove. This is a 

 small pebbly cove, some 50 yards across, surrounded, except at the seaward 

 opening, by vertical cliffs 40 or 50 feet high. The rocks are dark-grey slate, 

 with two single beds of grey grit appearing in the western cliff, both dipping 

 steadily to the south at 50° or thereabouts. This dip is so obvious that an 

 observer might readily be pardoned who entered it in his note-book as the dip 

 of the whole mass of rock, and allowed it to form an element in his calculations 

 for the thickness of the group. I was at first doing so myself ; and had there 

 been a path out of the cove to the eastward, might have been satisfied with the 

 observation, and passed on. The only entrance to the cove by land, however, is 



