2 TOFOGRAPHY AND GEOLOGY. 



of Europe possesses the same characters from Bantry Bay to the North 

 Cape. 



In general surface Ireland may be described as basin-shaped. The 

 traveller will be struck by the mountainous appearance of the coast. Jour- 

 neying westward from Holyhead, he may see from afar the blue line of the 

 Wicklow Mountains, rising 2,000 to 3,000 feet above the sea. As he 

 approaches Dublin, the details become clear ; the rounded bosses of KiUiney, 

 the bold promontories of Howth and Bray, the broken masses of the foot- 

 hills above Enniskerry, are only a foreground for that great granite moor- 

 land, which extends for seventy miles into the south. At Greenore he 

 meets a still more picturesque coast, the huge domes of the Mourne Moun- 

 tains contrasting with the rugged Carlingford ridge, above the quiet water 

 that stretches up to Newry. At Belfast the rim of the country is presented 

 to him in the form of long black scraps, terraced and forbidding, the edges 

 of the high plateaux that spread from Carrickfergus away to Limavady. If 

 our traveller passes westward, and rounds the coast of Donegal and Mayo, 

 he views walls of rock at times 2,000 feet in height, the noblest cliffs in all 

 the British Isles ; he then encounters rugged Connemara, and the high 

 limestone terraces of northern Clare. Farther south, peak after peak, 

 range after range, bars him out from the interior of the country, culminating 

 in the grey and cloud-capped masses that look down on Bantry Bay. 



Surely this Ireland must be a land of mountains. Yet the same traveller 

 may cross from Dublin to Galway, a distance of 1 1 5 miles, without encoun- 

 tering a genuine hill upon the way. He may pass, again, from Dundalk to 

 Mallow, and will feel himself in a great plain, above which a few ranges 

 rise, quite unimportant when compared with the extent of brown bog and 

 level meadow land. The highlands of Ireland are, in fact, massed upon its 

 margin ; while the central area is a broad depression, in which numerous 

 bogs and lakes have gathered. There is thus no well-defined watershed 

 in the country, with rivers radiating from it. It seems much a matter of 

 chance whether a stream rising in one of the central counties should run 

 into the Irish Channel or the Atlantic. The plain is, in fact, a sort of 

 gathering ground for the waters that trickle from the surrounding hills, and 

 for the sand and gravel that they wash down. 



It is well known that definite mountain-ranges result from the crumpling 

 together of rocks in the earth's crust, and that this crumpling has been 

 repeated after very long intervals of time. M. Bertrand and Professor 

 Suess have shown us how the main folds in Europe can be grouped into 

 four series, each of which has probably some representative in Ireland. By 

 its very mode of occurrence on the spherical surface of the earth, an upward 

 fold, called by geologists an anticlinal, is accompanied by a downward 

 fold, styled a synclinal ; and commonly a number of anticlinals and 

 synclinals occur together, giving us a contorted series (Fig. 2). The 

 results of earth movements are complicated by actual fracturing of the 

 crust ; and the rise of one region usually implies the breaking up and faUing 

 in of another. When we examine the mountain chains in detail, it by no 

 means follows that the crests of ridges are formed by individual anticlinals. 

 Where the rocks are brought up from below in the crowns of the folds are 

 such as resist the atmospheric agents, while softer beds lie in the synclinals, 

 the rise and fall of the weathered surface may correspond fairly with the 

 underlying folds. This is beautifully exemplified throughout the south of 

 Ireland. Commonly, however, the surface ridges give us little clue to the 

 precise type of fold that underlies them. A s)'nclinal of resisting rock, like 



