a-year, and mark how sharply the debris is scoured away by the tide and laid down in the long, flat, silty reaches of the Humber and the coast of Lincolnshire. Or take the alternating shales and sandstones of the St Andrews cliffs, and note the encroachment of the sea as it slowly but surely undermines them; and yet not a particle of debris is left at their base—the whole being borne away by the tide as fast as formed to the sands and sand-dunes (Pilmoor and Tentsmoor) that stretch away in miles between the mouths of the Eden and Tay.

As sure as degradation takes place in one locality, so certainly does accumulation occur in another, and this by processes whose every mode we can watch, and whose rate of progress we can determine. It is by this reciprocal process of waste and reconstruction that hundreds of acres of headland and promontory in these islands have been wasted away, and thousands of acres of low-lying sea-fen and sanddune accumulated. And when we consider the millions of miles of sea-coast that are exposed to the waves and tides and currents, we can readily imagine how much, in the course of centuries, the distribution of sea and land must be changed, and all that is dependent thereon affected. The inland waste that takes place through frosts and rains and rivers is no doubt great, but having reference chiefly to altitude it makes comparatively little impression; whereas the waste by the sea-shore being horizontal, creates new relations between land and water, and is everywhere followed alike by new physical and new vital results. The headlands and promontories of our forefathers are now farout "stacks" and "needles" washed by the waves; the Saxon churches and graveyards "by the sea" have long since been swept away; and the "seaport" of six or seven centuries ago is now, in many instances, the site of the inland grange, with its green fields and ditches.

"There rolls the deep where grew the tree;
Oh Earth! what changes hast thou seen?
There where the long street roars has been
The stillness of the central sea.

The hills are shadows, and they flow

From form to form, and nothing stands;
They melt like mists, the solid lands,

Like clouds they shape themselves and go."

Nor is it merely waste and reconstruction that are so perceptible by the sea-shore, but that slow uprise or depression of the land which occurs in so many tracts can be studied and proved only by observation along the coast-line. The inland dweller might remain for ever ignorant that his country was either rising or sinking, but a few rambles by the sea-side will convince him whether elevation or subsidence is going on-the former by the level lines of raised beaches now high above the waters, the latter by the submergence of lands and forests and buildings that must at one time have been high and dry above the tides. There is no study within the whole range of geology more attractive than these oscillations of the land; the terraces of raised beach, the line of caverns, and the submarine forest, all proving that, independent of exterior waste and reconstruction, there is a process of upheaval and depression going forward by which the distribution of sea and land is changed, and all that is dependent on the position, contour, and relief of the land-masses must be effected. By the sea-shore alone can these phenomena be studied, and the geologist who neglects this field foregoes the power of proving some of the most important problems in his science.*

It is thus by the sea-shore that the young geologist can learn so much of his favourite study, and this much so readily and so well. The magnificent sections stretching for miles, with every line and layer unobscured, with every

* See Chapter on "Raised Beaches and Submarine Forests."

bend and fold apparent, and every dyke and fault and fissure standing out as if in a diagram, present physical illustrations rarely or ever to be witnessed in inland situations. In no other place can the relations of rock to rock be better displayed, and nowhere is the structure of the earth's crust more fully revealed. The rapid disintegration of the coast in certain localities, and the extensive rock-falls that take place every winter, afford, too, the finest opportunities for the collecting of fossils; the amount exposed by a single fall often exceeding what could be mined or quarried dur ing a twelvemonth. And then the perfection in which they can be obtained compared with the gropings of the miner, or the chance chips of the quarryman. Again, in the waste and reconstruction that are ever taking place by the sea-shore, he can study to perfection those processes by which the rocky crust is weathered and worn away in one tract, and in another re-formed by the accumulation and assortment of the drifted debris,-an example-it may be within his morning's walk-of that ceaseless circulation of matter which is ever passing from one condition to another, from the formed to the unformed and back again, and this without diminution or loss. And, lastly, by the sea-shore alone can he study those gradual elevations and depressions by which the position, the contour, and the altitude of the land are affected, and through these the climate they enjoy, and the flora and fauna with which they are peopled. In fine, in the Sea-Shore the student has a great geological preceptor, and a lesson at every turn; while in its varied scenery, its life, and busy industry, he will find endless themes for thought, and inexhaustible sources of intellectual recreation.

LOCHLANDS, AND THE TALE THEY TELL.

A TRAVELLER over the Lowlands of Scotland will often hear the name of "Lochlands" where no loch or lake, mire, marsh, nor swamp meets his view. He sees around him a tract of uniform flatness intersected by drains and ditches, with here and there a rising mound, and, encircling the whole, a bank-like margin of varying slope and altitude. Should he visit the spot before the morning mists of summer have been dispelled, or after sunset, when the night fogs are creeping along the valleys, he will find himself enshrouded in a lake of vapour, with the bank-like margin dry and visible all around. Or should he look down from the margin on the foggy flat below, the slightest touch of imagination is only required to convert the whole into a misty sheet of water-the loch as it spread out in former ages. These "lochlands" are but the sites of ancient lakes, which have been drained partly by the hand of man, but chiefly by that slow process of silting which is ever going on wherever there is an entering stream and the presence of vegetable and animal life in the waters. Cut through by ditch and drain, they tell a curious and far-back tale-curious, as of most varied interest, and farback, as carrying us ages beyond the oldest standing-stone

or earliest burial-cairn.

Let us glance at some of the facts

they have chronicled and the history they unfold.

And first, let us trace the process by which the old lake has been obliterated, and by which every existing lake is steadily tending to obliteration. Wherever there is an entering stream or runnel, there sand, mud, and miscellaneous debris are sure to be accumulated. Clear as the running stream may appear in summer, there are times after sudden and heavy rainfalls, the melting of the upland snows in spring, and the like—when the current is discoloured and laden with earthy impurities. When the stream comes to rest in the lake, these impurities fall to the bottom-gravel, sand, and mud, according to their respective gravities; and thus year after year, and century after century, the lake becomes shallower, or even indeed converted into alluvial meadow-land. And as the waters become shallower this silting process is greatly facilitated by the growth of reeds, bulrushes, equisetums, and other aquatic plants which spring up on the little deltas, and act as so many sieves and screens to intercept and entangle the stream-borne debris. But not only do these plants intercept the floating impurities, their own annual growth and decay are incessantly adding to the accumulation, and in a few generations the reedy mire is converted into the rushy meadow. In this way the little deltas are continually encroaching on the lake, while its central parts are also receiving more or less of impalpable sediment, or are the nursing-grounds of myriads of aquatic molluscs-lymnea, paludina, planorbis, &c.-whose shells, generation after generation, accumulate in limy layers of marl, which further tend to the shoaling of the waters. And while stream and vegetable and animal growth are thus gradually filling up the lake, its waters are further diminished by the auxiliary process of the out-flowing stream, which is as persistently and inces