Expressed in the simplest form, the relation of this structure to marine erosion may be stated thus: Hard rocks present greater resistance to the inroads of the sea, and consequently tend to project as headlands; soft rocks are more easily demolished, and, therefore, recede before the waves into creeks and bays. The waste of the eastern shores of the British Isles is more rapid than that of the western, because though the waves of the North Sea are less powerful than those of the Atlantic, yet the rocks forming the coast-line on that side are, as a whole, more easily worn away than those on the west side. If the soft sandstones and shales, clays and sands of the eastern sea-board were open to the full fury of the western ocean, there would be a sad yearly tale of loss and ruin. Perhaps, it may be objected that the western coast is far more indented with inlets than the eastern, and therefore shows more strikingly the wasteful powers of the

sea.

But these indentations, as will be afterwards pointed out, are not the work of the sea; they are, in truth, submerged land-valleys, and point to the prolonged action of sub-aërial waste when our islands stood some hundreds of feet above their present level, and were probably joined to the mainland of Europe.

It would be interesting if we could trace the gradual retreat of the Scottish coast-line since man became an inhabitant of the country, or even since the time to which the earliest historical notices refer. No written records of such changes, however, go farther back than, at the most, three or four hundred years. There are, indeed, traditions of land having once existed, where for many a century have rolled the waves of the salt sea; just as in Cornwall there still survives the memory of a district, called the Lionesse, now covered by the Atlantic, but which in the days of the Knights of the Round Table is said to have been rich

and fertile.

But such traditions are too vague to be, at least in the meantime, of any geological service. It is with the time of written history, therefore, that we must deal. Though this period is short, yet it furnishes us with some instructive lessons as to the progress of marine erosion. Let me conduct the reader in an imaginary voyage round the sea-margin of Scotland, and while the breeze drives us merrily onward he may be interested to listen to some tales of the wild havoc that has been wrought on

the shores, during the last few generations, by the same sea whose waves are now leaping and laughing around

us.

From the mouth of the Tweed we set sail northwards, and skirt the abrupt rocky coast which forms the sea-board of Berwickshire. The cliffs for many miles are steep or vertical, rising, near St. Abb's Head, to a height of 500 feet above the waves,-the highest sea-cliffs on the eastern sea

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board of Britain,—and here and there interrupted by narrow bays and coves, which have in several instances been selected as the sites of fishing villages and hamlets. We see from the wasted and worn look of these cliffs what a sore battle they have had to fight with the ocean. Craggy rocks, isolated stacks and sunken skerries, that once formed part of the line of cliff, are now enveloped by the restless waves. Long twilight caves, haunted by otters and sea-mews and flocks of rock-pigeons, have been hollowed out of the flat Carboniferous sandstones and the contorted Silurian greywacke (Fig. 10), and are daily filled by the tides. In storms, the whole of these vast precipices, from base to summit, is buried in foam-the pebbles and boulders, even on the sheltered beaches, are rolled back by the recoil of the breakers, and hurled forward again, with almost the force and noise of heavy cannon. But a line of abrupt rock presents such formidable obstacles to the advance of the sea that the rate of waste is extremely slow. Passing onward along this coast, with its green bays and dark gloomy cliffs, we round the headland of St. Abb's, and observe that it stands there, at once a bulwark against the waves and a mark of their advance; for, being a mass of hard porphyry, it has been able in some measure to withstand the assaults of the ocean which have worn away the greywacke and shales around. Sweeping across the Bay of Dunglass, we observe that the cliffs at once become less lofty and irregular where the curved Silurian rocks are replaced by the Old Red and Carboniferous sandstones. We pass the sandstone cliffs of Cove (where the old fishermen used to point to great inroads by the sea during their lifetime), and then the shores of Skateraw, where, in the early part of this century, stood the ruins of an old chapel, which were swept away many years ago, the tides now ebbing and flowing over

their site.1 entrance of the Firth of Forth. There the proofs of degradation and decay come before us with a melancholy reality. The old castle, once so formidable a stronghold, is almost gone-two tall fragments of wall and some pieces of masonry at a lower level being all that is left. The rains and frosts of many a dreary winter have broken down the ramparts, and the hand of man, more wanton and unmerciful in its destruction than the hand of time, has quarried the stones and blasted the rocks in the excavation of the harbour. But the sea has all the while been ceaselessly at work wearing away the very headland on which the ruin is perched. The time will come, at no very distant date, when the Dun or hill from which the castle takes its name, will have disappeared, and its site will be marked only by a chain of rocky skerries. A little to the west of the castle, a huge mass of the sandstone cliffs, undermined by the sea, fell during the night some thirty years ago. The scar is yet visible, though the pile of ruin at the foot of the precipice is being broken up and carried away by the waves.

Farther west stands the castle of Dunbar at the

It might have been supposed that the comparatively sheltered estuary of the Forth would be free from any marked abrasion by the sea, yet even as far up as Granton, near Edinburgh, during a gale from the north-east, stones weighing a ton or more have been known to be torn out of a wall and rolled to a distance of thirty feet. Hence, within the last few generations, the sea has made encroachments, sometimes to a considerable extent, along the whole coast of the firth, even as far up as Stirling. Tracing the southern shores in a westerly direction from Dunbar, we find

1 Popular Philosophy, or the Book of Nature laid open upon Christian Principles. Dunbar, 1826, vol. ii. p. 160.

2 Thomas Stevenson, Trans. Royal Soc. Edin. xvi. 27.

that the low sandy tracts at the mouth of the Tyne, and again from North Berwick to Aberlady, have suffered loss in several places. Farther on, near Musselburgh, there was a tract of land on which the Dukes of Albany and York used to play at golf in former days, but which is now almost entirely swept away. The coast of Edinburghshire has in like manner lost many acres of land. Maitland, for instance, in his History of Edinburgh, describes the ravages of the sea between Musselburgh and Leith, which had occasioned the 'public road to be removed farther into the country, and the land now being violently assaulted by the sea on the eastern and northern sides, all must give way to its rage, and the links of South Leith, probably in less than half a century, will be swallowed up.'1 The road alluded to has had to be removed again and again since this passage was written. Mr. Robert Stevenson 2 remarked in 1816, that even the new baths, erected but a few years before at a considerable distance from the high-water mark, had then barely the breadth of the highway between them and the sea, which had overthrown the bulwark or fence in front of those buildings, and was then acting on the road itself. Maitland speaks also of a large tract of land on both sides of the port of Leith, which has likewise disappeared. Nor are the inroads of the sea less marked as we continue our westward progress. The old links of Newhaven have disappeared. If the calculations of Maitland may be believed, three-fourths of that flat sandy tract were swallowed up in the twenty-two years preceding 1595. Even in the early part of the present century, it was in the recollection 1 History of Edinburgh, p. 499.

2 In an excellent paper on the Bed of the German Ocean, in the second volume of the Wernerian Society's Memoirs, to which I have been greatly indebted in collecting the statistics given in this chapter. History of Edinburgh, p. 500.

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