the remembrance of people yet living, are now no more. Wherever a high sandbank has been entirely worn away the soil under it is found to have been either a rich loam or black moss. In many such situations, vestiges of houses, enclosures, churches, and burying grounds appear.'1

The results of long-continued marine erosion and of the manner in which these are modified by geological structure

FIG. 15.--Cliffs of Archæan Gneiss, with pink pegmatite veins, Cape Wrath. are nowhere more instructively displayed than along the western sea-margin of the Scottish mainland. We may specially distinguish three types of sea-cliff there, each of which owes its peculiar characters to the internal structure of its component rock. These types are: (1) the crystalline schists, and

more particularly the Archæan gneiss; (2) the red (Cambrian) sandstones; and (3) the basalt-escarpments. Of the first type the most striking examples are to be found in the great range of gneiss precipices which, rising to a height of 300 feet above the Atlantic, terminate northwards in Cape Wrath. The varying nature of the gnarled, crumpled gneiss, its irregular foliation and jointing, its bands of dark hornblende, and ramifying pink veins of pegmatite, conspire to give it very unequal powers of resistance in different parts of its mass. Consequently, it projects in irregular bastions and buttresses, and retires into deep recesses and tunnels, showing everywhere a ruggedness of aspect which is eminently characteristic (Fig. 15). In striking contrast to these precipices are those of the second type: the Cambrian sandstone which, a few miles to the east of Cape Wrath, rise in vast vertical walls of rock to a height of 600 feet. These nearly horizontal strata are cleft by their perpendicular joints into quadrangular piers and projections, some of which even stand out alone as cathedral-like islets in front of the main cliff. The sombre bands of dull red and brown are relieved by lines of vegetation along the edges of the nearly flat beds, which project like vast cornices and serve as nesting-places for crowds of sea-fowl. At various parts of the coast-line as far south as the mouth of Loch Carron, these red sandstones give rise to similar scenery, the cliffs of Handa Island being specially notable. The third type, that of the basalt plateaux, reaches its most impressive development along the west of the island of Skye, where a magnificent range of precipices rises to 1000 feet above the sea. These ramparts of rock are built up of successive, almost horizontal, sheets of basalt which rise one over another like gigantic courses of masonry. The durability of the different layers varies greatly, and the

system of joints is much less defined than in the Cambrian and Old Red Sandstone. Consequently the mural character is less prominently marked. Where the basalt is harder, it rises with a perpendicular face, but the more decomposing bands crumble into irregular belts, and not infrequently decay into steep slopes that support a coating of rich green grass. The contrast between the dark hue of the rock and the bright verdure that grows on it is one of

the most striking effects of colour in the Western Highlands (Fig. 16).

The chain of the Hebrides, like a great breakwater, fronts the western coast of Scotland, which it no doubt in some measure protects from the full force of the Atlantic breakers. The greater hardness of the rocks, as compared with those of the east coast, must also have contributed to retard the progress of the waves. Nor must we forget that the absence of harbours, maritime villages and towns on the western sea-board

has probably deprived us of a record of the waste of these shores within the historical period. Knowing the actual force of the waves, and seeing how much they can effect in a stormy winter, we cannot doubt that during the last few hundred years there must have been more or less loss of land, even along that iron-bound coast.

In the Kyles of Bute, a tract of low land to the north of Kames Bay has been so encroached upon by the tides that a road which skirted the beach had been thrice removed farther inland during the thirty or forty years that preceded 1864.1 Along the shores of the estuary of the Clyde, the sea has in some places removed a considerable part of the coast-line even within recent times. To the south of the town of Ayr, a cliff of volcanic tuff rises vertically from the beach, bearing on its verge the picturesque ruin of Greenan Castle. The walls overhang the precipice, and the sea is hollowing out the rock below. Yet within the recollection of a venerable lady who died some years ago, there was room for a horse and cart to pass between the castle and the edge of the cliff. During the last hundred years, therefore, a slice of solid rock, perhaps six or eight feet broad, has been cut away from this part of the coast. A short distance farther south, a spring in the middle of a field, a few feet above high-water mark, was enclosed as a well some eighty or ninety years ago. Since then that part of the field which lay between the well and the sea has been eaten away, and the spring now rises at the edge of the shingle of the beach.2

The shores of Loch Ryan, which seem so well sheltered alike from the Atlantic and the Irish Sea, have suffered considerably within the last two or three generations. Mr.

1 My much esteemed friend the late Rev. Alexander Macbride, of Ardmory, Bute, pointed this fact out to me in 1864.

2 These facts were communicated to me by the late Dr. Sloan, of Ayr.

Stevenson found in 1816 that at the town of Stranraer, the houses along shore had formerly gardens between them and high water, but that of late years the inhabitants had been under the necessity of erecting bulwarks to secure the walls and approaches to their houses. Farther down the loch, at the village of Kirkolm, a neck of land called the Scar Ridge had once extended into the sea about half a mile. Cattle were wont to graze upon it, but it was then nearly washed away, and in high tides it was laid almost wholly under water.1

The southern coast-line of Scotland lies open to the full fury of the Irish Sea. When the wind blows strongly from the south-west, the rocky precipitous shores of Wigton and Kirkcudbright are white with foam, headland after headland standing out into the breakers that roll eastward far up into the recesses of the Solway Firth. In a series of experiments made during the fine summer of 1842, at the Island of Little Ross, on the coast of Kirkcudbright, it was found that the average force of the waves was about 328 lbs. on the square foot, or rather more than half the average summer force of those at Skerryvore, the greatest recorded pressure being one of 664 lbs.2

From this short and incomplete survey of what has been done by the waves round the Scottish coast during the last two or three hundred years, it is evident that although here and there from local causes, such as the accumulation of sand and shingle, there may have been a slight gain of land, the general result has been a loss. Where the coast is rocky and precipitous, this loss may not be measurable, but yet the ruined masses, undermined by the waves, tell their story not less convincingly than where there are historical records of the devastation.

1 R. Stevenson, Mem. Wer. Soc. ii. p. 476.

2 T. Stevenson, Trans. Roy. Soc. Edin. xvi. 30.