In the chain of the Inner Hebrides, broken as it is in outline and varied in its types of scenery, there is no object more striking than the island of Eigg. Though only about five miles long and from a mile and a half to three miles and a half broad, and nowhere reaching a height of so much as 1300 feet, this little island, from the singularity of one feature of its surface, forms a conspicuous and familiar landmark. Viewed in the simplest way, Eigg may be regarded as consisting of an isolated part of the basaltic plateau which, instead of forming a rolling tableland or a chain of hills with terraced sides, as in Antrim, Mull and Skye, has been so tilted that, while it caps a lofty cliff about 1000 feet above the waves at the north end, it slopes gently along the length of the island to the south end. In its southern half, however, the ground rises, owing to the preservation of an upper mass of lavas, which denudation has removed from the northern half. On this thicker part of the plateau stands the distinguishing feature of the island, the strange fantastic ridge of the Scuir, which, seen from the north or south, looks like a long steep hill-crest, ending in a sharp precipice on the east. Viewed from the east, this precipice is seen to be the end of a huge mountain-wall, which rises vertically above the basalt-plateau to a height of more than 350 feet. The accompanying map (Fig. 276) shows that the ridge of the Scuir corresponds with the area occupied by a mass of pitchstone, and that while the basaltic rocks cover the whole of the rest of the southern half of the island, they gradually rise towards the north, successive members of the Jurassic series making their appearance until, at the cliffs of Dunan Thalasgair, the latter cover the greater part of the surface, and leave the volcanic rocks as a mere stripe capping the cliffs. In the section (Fig. 277) the general structure of the island is represented. [Illustration: Fig. 276.--Geological Map of the Island of Eigg. P, Pitchstone-lava of the Scuir; R, old river gravel under pitchstone; _p p_, small veins of Pitchstone; _b b_, dykes, veins and sheets of intrusive basalt; the short black lines running north-west and south-east are basalt dykes; _f f_, granophyre sills; D, bedded basalts with occasional tuffs; F, andesite; 1, 2, 3, 4, clays, shales, sandstones, limestones, etc. (Jurassic); xx, Loch Beinn Tighe; x, Loch a Bhealaich. --> General dip of the rocks. ] [Illustration: Fig. 277.--Section of the geological structure of the Island of Eigg. P, Pitchstone-lava of Scuir; _c_, ancient river-gravel; _p p_, pitchstone veins; _f f_, intrusive granophyre, etc.; _b b_, dolerite and basalt dykes and veins; B, intrusive dolerite and basalt-sheets; D, bedded dolerites and basalts; F, andesite bed; 1-4, Jurassic rocks.]