In this cut, _a_, _a_, _a_, are intended to represent the stratified rocks, and _b_, _b_, _b_, the others, which from their position are sometimes called _overlying rocks_, and they mostly consist of a substance called _basalt_, which is nearly black and very hard, and occasionally with white and coloured minerals imbedded in it. There are two states in which it is found; in one, it occurs in masses without any particular form, and in the other state it constitutes pillars shaped with great accuracy and regularity. [Illustration: PLATE VIII. STAFFA.] The island of Staffa, one of the western islands of Scotland, and the Giant's Causeway, on the north coast of Ireland, near Londonderry, are remarkable instances of the latter state; and as I have seen them both, I will tell you what sort of places they are. STAFFA. This wonderful island was not generally known to exist, even by the inhabitants of Scotland, till the last century, when Sir Joseph Bankes happened to see it, and published an account of it. Since then it has been visited by numbers, and lately a steam-boat has regularly plied to it twice a week, from the little town of Oban, in Argyleshire. It was in this way that I went, and a most delightful trip we had of it. The steam-boat left Oban in the afternoon, full of kind light-hearted people, who seemed fully resolved to enjoy themselves. In the evening we reached the island of Mull, where we were to spend the night. The inhabitants of Tobermory, (the little capital of Mull,) anxiously look out for the arrival of the steam-boat, for they are very poor, and the little money which the passengers spend, is a great object to them. On these occasions the inns are seldom large enough to accommodate all the strangers, and then a strange scramble takes place to get lodgings for the night. Most of our party succeeded in doing so, and the rest remained on board the steam-boat. We went to see a beautiful little estate on one side of the harbour of Tobermory, which belongs to the son of the old Laird of Coll, whom Dr. Johnson visited. The grounds are nearly in the shape of a triangle, and the two sides that are away from the sea, are formed by lofty rocks with several beautiful waterfalls; and in the middle is a pretty lake. Except the house on this estate, there are scarcely any good houses in or near Tobermory, and the inhabitants are very ignorant and poor. Many of them who could not speak any other English words, ran after us to ask us for pence and tobacco. We started early in the morning, and passed several small islands of curious forms, composed of basalt; one in particular, which is called the Dutchman's cap, shaped like this. [Illustration] As we approached Staffa, on the north side, we could see scarcely anything of the pillars. It appeared a mass of Basalt, of very irregular shape, rising abruptly out of the sea, scantily covered with grass on the upper surface. [Illustration]