Embanked land is denuded. appears on the scene, if fine alluvium plasters up the shingle enough to hold back the water, it is a common practice to dig a trench a few feet into the shingle which lets the water flow off in a stream, or if circumstances admit, a trench is cut through the shingle and occasionally cleared. Then come sluices and iron piping through the shingle bank. The land drainage is let out at low water and the sea kept out at high water. Millions of acres of our best pasturage are held on this tenure. But when the streams are embanked and are let off to the sea so perfectly as to prevent their natural annual overflow, annual denudation, of the old alluvium will take place instead of deposit of new alluvium, and the land may again become denuded far below the usual tidal level. The natural progress of such shingle banks is inward, that is, landward. In this progress they include and preserve the stems and roots of any trees which are in their line of march while the heads decay and fall. As the shingle bank travels inland the sea erodes the site on which the bank lately stood and exposes between high and low water the peat and the stems and roots which the shingle had covered. This may be seen at such places as Pevensey sluice, or at Pebblesham at the west end of St. Leonard's (and the Ham which the railroad traverses there is composed of pebbles), at Hastings opposite Mantells 'diluvial valley.' In a minor way it may be seen in the bays of Torbay. To the centre of a bay, as Torbay, the beach travels from each horn, from Berry head and from Hope's nose by the same wind. Hence the accumulation of beach at the centre of Paignton, and the very same force which has carved this bay out of the soft sandstone between the two hard limestone heads throws up this bar of protection. The Paignton beach travels from the Torquay or Hope's nose side to the north foot of Roundham Head. The Goodrington beach travels from the Brixham (Brides-ham) or Berry head side to the south foot of Roundham head, and walls are built, not to keep back the sea water, but the sea land. Through these accumulations of beach the streams are now passed artificially. In former ages before art let the water out at low water, marshes, bogs and peat have accumulated behind the beach. Peat is seen in front of it now below high water mark. In this peat at Torre Abbey the stumps of trees are seen. As the prime agent in these movements, the wind, is the most changeable gentleman on earth, so are his works. They are constantly being placed, displaced and replaced; and in continuous gales boulders not only pass backward and forward, round headlands from one bay into another, but perform this countermarch constantly till they are ground into sand or till they get high and dry on a settled beach or into a settled line of travel. We have here a vast, universal and eternal agency which is always at work and which has been always at work, and which will be always at work on every shore throughout the globe, and which, without the aid of ice, or icebergs, or 'glacial epochs,' or 'waves of translation,' or 'great advancing waves from the north or other such monstrous assumptions, is always forming accumulations of transported boulders here, of shingle there, and of sand in another place, and this simple cause has originated all those inland drifts which are entirely composed of boulders and water-worn pebbles with foreign pebbles among Northern drift them. That is, all those drifts (and I include what is absurdly called northern drift') are simply ancient sea beaches; and as causes of the ' northern drift' the monstrous machinery and decorations which I have mentioned may be regarded and discarded velut ægri somnia. ancient sea shores. As every part of the earth which is now above the sea has once or more than once been under the sea, so it is only natural that in every part of the earth we should find traces of the sea and of sea shores. Sea drift with the marvellous mixture of pebbles from granite and trap to the chalk flint, may be seen in six different positions within the narrow limits of my own county of Hampshire. The materials of this sea drift have been placed in these six different positions under circumstances most distinct and in some cases at periods most distant one from the other. First and foremost, on our sea shores at this instant may be found mingled pebbles from every geological formation in England. Second, The same mixture is found in our raised beaches; and since the shore on which the Romans built at Dover is at the same level as the present shore, our raised beaches must be at the least 2,000 years old. Third, the same mixture of travelled pebbles is found in the gravels which bed our upper dry chalk valleys. These gravels are, indeed, almost entirely angular, or only slightly worn and untravelled. They are the residuum of denudation. That is, while the wash of rain cut the valley through the clay-capped chalk, the travelled pebbles of the tertiary clays were dropped in the bottom together with the untravelled angular secondary flint. Fourth, in Origin of the the Druid sandstones of Froxfield, on the top of the clay-capped chalk hills of the Petersfield hangers, and in the pudding-stones of Bridestone lane, near Alton, I have found rounded pebbles of quartz mingled with pebbles of flint, and I should guess that as all conglomerates must have Druid sand stone. been formed on sea shores, all conglomerates will be found to be mixtures of travelled pebbles. These Druid sandstones and conglomerates have nothing to do with icebergs, nor have they themselves travelled, though their materials have. They are simply sand or pebbles of tertiary sea shores accidentally hardened into stone by water impregnated with iron, carbonate of lime, or flint. When they are on the bare chalk they also are the residuum of denudation, that is, these hard nodules remain after the soft clays have disappeared from the chalk by disintegration and the wash of rain. Fifth, over the entire surface of our ploughed land, whether of tertiary clay or of secondary chalk, the same mixture of travelled pebbles may be found. The clays have been deposited in the sea as a general rule farther out to sea than the sands, but in storms at high water sands and these pebbles have been washed into them. So that gravel-pits exist on our clay hill-tops entirely of rounded pebbles. When on the chalk, these pebbles must again be the residuum of denudation, that is, they remain after the clays which held them have disappeared by the wash of rain; and Sixth, this marvellous mixture of travelled pebbles from granite and trap to the chalk flint is to be seen in the greensands of Woolmer Forest under the chalk. Have icebergs or the 'great advancing |