in the west of Derry, is seen at the distance of three miles inland; it is remarkable for the grandeur of the scenery presented by its shattered precipices.
Of the island of Rathlin or Raghery, the section represents only the cliffs extending from its most westerly promontory to the centre of its southern line of coast. From the point where the section terminates, the precipices round the southern cape and the eastern and northern shores are exclusively composed of basalt, and frequently present columnar groups. (See page 182.)
To the conjecture of Dr. Berger, however, that sandstone and older rocks exist at no great depth in the south-eastern quarter of the island. (See page 151.) the positive assertion of Mr. Hamilton must be considered as adding great weight. “ An heterogeneous mass of freestone, coals, iron ore, &c. which forms the east side of Ballycastle Bay, and appears quite different from the common fossils of the country, may be traced also directly opposite running under Raghery, with circumstances which almost demonstrably ascertain them to be the same veins.” Letters on the coast of Antrim, page 8.
From the exact correspondence in structure between the opposite points of coast upon this island and the main, Mr. H. infers that “ Raghery standing as it were in the midst between this and the Scottish coast may be the surviving fragment of a large tract of country, which at some period of time has been buried in the deep.”
The pebbles of sienite which are scattered over various parts this island, and must have travelled hither from Cushleak, concur to prove the later formation of the channel now separating it from the mainland. Dr. Mac Culloch observed appearances analogous to these in the island of Staffa, and deduces from them the same conclusion. See Transactions of the Geological Society, Vol. II. page 207.
