The elemental powers which are constantly at work in Nature all around us are upon a vast scale; a scale, in fact, which is immeasurable by us, except when observed under certain favourable circumstances. As our practical ideas of locomotion are immensely surpassed by the speed of the Earth’s rotation on her axis, which is at the equator rather more than 1000 miles an hour, and yet far more surpassed by the rate at which she moves in her orbit round the Sun, which exceeds 20,000 miles an hour, so also our experience of a puff of wind on the hillside, or a dash of water in our face, when a slanting shower or the spray from a cataract salutes us, gives us no conception of the stupendous powers which are exerted when the sea, convulsed by a storm, rages along some unprotected coast.

Once in my life, I remember being knocked down by a blast of wind; and several times, as I suppose has happened to many persons, I have been floored by an unexpected billow while bathing. I always made this reflection at the moment: “Its power is not known: it has floored me easily enough, but perhaps it would have felled an ox.”

But a wave impelled by the gale, which could take an ox off his legs, is nothing at all. What is the measure of force actually applied when a stout ship is shivered on a lee shore? No one knows. When the Clarendon, West-Indiaman, struck on that fatal “race” off Blackgang Chine, she went utterly to pieces within seven minutes! Yet, what a delicate thing is AIR! What a yielding thing is WATER! But then the air and water threw her on a lee shore.

Observations, carefully made at the right time and place, enlighten our ignorance upon all these matters. Air, delicate as it seems, when compressed, explodes in the roar of the thunder; and water is almost incompressible, and therefore its blow will knock down anything.

Let us speak first of the power of the WIND. The sands of the Desert, as has been said, are powdered quartz and quartz is a heavy substance; but when a strong wind ploughs the surface of the Desert at an angle, these Sands are lifted, and made to gyrate in spiral folds, and a huge column is formed—perhaps a hundred and fifty feet in height—and this monstrous trunk is presently carried along at whirlwind speed; and if it meet a party of travellers, they will be overwhelmed and buried.

It may be said that the sand is in very minute particles; and this is true. But if they are, therefore, the more easy to disturb and to catch up aloft, they are all the more difficult to bind together in a spiral form, and to hurry along the desert unbroken.

The power of the wind, especially when it comes in sudden gusts, and with a whirling motion, against timber-trees and the upper parts of buildings, is only too well known; on wide, exposed plains, its fury, in the early part of the year, sometimes brings destruction to everything within its range. But it is on the open sea, where the hurricane, once let loose from heaven, can sweep, unchecked, perhaps for hundreds of miles, that the latent forces of this unseen element are revealed in all their terror and majesty. For here the wind not only has free scope, but it also finds another element, fluid but incompressible, to obey its impulse and follow in the course which it takes. If the WIND be like a wild spirit, the WATER is a mighty, irresistible body, endowed with motion by the other, and capable of any work, from the drowning of a sea-gull to the wrecking of a stately ship.

The waves which roll in from the open sea, when the tide is making, are the most powerful. Fortunately, these do not reach the shore with quite the same force which they exert at the distance of some miles from it; but in exposed situations, their altitude and momentum are very great. The billows of the Atlantic which break on the western coast of Ireland run from thirty feet to fifty feet in height, and they arrive on that coast with an impetus which has (up to a certain point) been gaining strength, perhaps for half the time of a tide. It was this fearful onset, from a foe that never slumbered, which broke up and rendered useless the eastern extremity of the great Submarine Electric Telegraph Cable between Ireland and America.

It has now been decided that when stormy winds prevail long in one direction, another and peculiar force is given to the waves on which they operate. For the wind, by pressing long on the side of a wave, changes its form from that of an upright ridge (i.e. with vertical axis) to one which has a stoop or bend, sometimes of great inclination. Such a wave will come in upon the shore with far greater momentum, for its velocity has been enormously increased, while its bulk is nowise diminished. The speed which the water acquires under the influence of a prolonged sou’-wester on the coasts of Sussex and Hampshire, although there the gale has only traversed the breadth of the Channel, is very notable at times. At Lowestoft and at Peterhead, easterly points of land, the danger of the winds from the North Sea is proportionally far greater, as a larger body of water has been continuously acted upon. For it must always be remembered that a wave at sea is simply an oscillation of the water which rises and falls in that place. The identical wave does not pass on to the shore, though it appears to do so; it is the motion which is propagated, and, as it were, handed on, like an electric shock through the successive plates of a battery. Now this motion increases with the onward career of the gale. “Vires acquirit eundo.” And when the mass of the fluid over which the wind is blowing has once been agitated, and the equilibrium of its upper layers been thoroughly disturbed, if the current of air not only continue, but wax stronger and stronger, there scarcely seems any limit to the momentum which the rolling wave may thus acquire. The arithmetic of a few facts upon this subject will, however, give us some idea of what that momentum must be on certain occasions.

It has been found, by experiment, that the velocity imparted to an incoming wave sometimes equals seventy feet in a second of time. Now this would give nearly one mile in a minute, if it were a projectile in free space; but the case here is, of course, different, since the wave is only a portion of the mass to which it belongs, and no individual wave travels very far. Still, the amount of rush and pressure which are exerted is altogether stupendous. Probably the breakers, which in an enduring storm rise against a lighthouse in the open sea, are among the strongest instances with which we are acquainted, and, next to these, I suppose, the billows off the Cape of Good Hope. But we may take those on the Irish coast, westward, as a well-known sample. I have often watched these—once in a gale of wind—and I have seen, in one as yet unbroken wave, a body of water which I should compute roughly at two hundred tons’ weight, and as having, at the moment, a velocity of not less than sixty feet in the second, discharge itself upon the reef of rock. On such occasions, if you happen to stand on the shore, you will feel the ground vibrate apparently, though the sensation is probably electrical. But let any one consider the conditions of the wave cited above, and reckon what is the force of the blow at the moment of impact. I have no doubt it would knock down a good strong house, if delivered against the upright face of it.

One winter, when I was at Sandown, in the Isle of Wight, a spot frequently mentioned in these pages, I found I was utterly unable to traverse the bit of open road reaching from the Fort to the point where the lane turns off to Yaverland. Yet I had on at the time a stout Cording’s waterproof, with sleeves, and a slouched hat tied under my chin, and held a powerful oaken stick in my hand to help me win my way. In fact, it was a trial of dynamics between me and the gale, whether this “body,” acted on by a continuous muscular force, in nearly a right line, could be propelled through that resisting medium. I am sorry to say, it could not; but, in the attempt, it lost a neck-button from its coat, and was within an ace of being blown into the hedge, like a certain “man in Thessaly, wondrous wise,” whom we have heard tell of in our childhood.

This storm held on for seven or eight hours, and as the sea rose many feet higher than usual under its influence, when the tide was well in, the strife of elements, and their combined assault upon the works of men’s hands were truly grand. A breach was made through the solid causeway, compact long ago of clay, and gravel, and boulders of flint, and guarded seaward by dykes of timber. This breach was effected, I have no doubt, by the stroke of the wave, as the sword of Roland is said to have cut through the rock in the fight of Roncesvalles. A wall of stout masonry, not above five feet in height, and supported behind by earthworks, so as to resemble an escarpment, yielded before the weight of water, as a pane of plate-glass would give way at the charge of a locomotive engine. Some twenty yards’ length of it was rent and thrown down. On examining this fragment afterwards, I found that the materials of the wall were solid blocks and angular bits of Wenlock limestone, and the cement used of the strongest. I believe, however, if it had been three times as strong a barrier, those waves would have levelled it.

I subsequently witnessed in that very neighbourhood a yet more furious tempest of wind, but had no opportunity of measuring its effects.

At Eastbourne, about two years age, I made acquaintance with a phenomenon in this line which was altogether new to my experience. We had a tremendous gale late in the autumn of 1857. I cannot exactly cite the quarter from which the wind blew, as I do not accurately know the points of the compass in their bearing on the town and bay; but the storm seemed to beat in from the south-east, as it faced the Marine Esplanade. I went forth, with perhaps a score of others, to gaze upon this magnificent “encountering shock” of earth, air, and water. We were all of us drenched to the skin by the dashing spray, and occasionally well-nigh swept off our legs by the gust; but we held on stoutly, till something saluted those nearest the beach, which rendered a retreat imperative. This was not the salt spray, nor the rattling hail neither, but a cloud of “skirmishers” in the shape of pebbles and gravel from the strand below. The sea had actually lifted the surface of the bed of beach, and whirled aloft some bushels of its solid contents. A coast-guard told me next day, that he saw a “flight” of pebbles, some of them as big as hens’ eggs, at least thirty feet high in the air; and he added, that if the direction of the wind had changed a little, every pane of glass on the ground and first-floor of the Esplanade must have been shivered to atoms. As it was, of course much damage was done to windows and sashes; but not by the actual pebbles.

After this gale had subsided, I ascertained by personal inspection that some hundred tons’ weight of solid shingle had been moved along the shore a distance of a quarter of a mile, in the space of a few hours. This was by the sidelong drag of the tide.

The village of Seaford, on this same line of coast, had long been in great danger of being swept away by the tide. Its outworks and very standing ground were perceptibly yielding, season after season.

About eight years ago, the inhabitants took the alarm, and drew up a remonstrance and petition, which were duly forwarded to the authorities. Proper officers were deputed to go down from London and report; and the result of their representations was that an able engineer from head-quarters was empowered “videre ne quid Respublica detrimenti capiat;” or, in the modern vernacular, to see that the Queen’s lieges in Seaford suffered no wrong.

The remedy hit upon was simple and forcible; but, assuredly, it was an instance of what is called “Hobson’s choice.” The engineer said, “There is only one thing to be done; a solid breakwater must be formed west of the town, to break the rush of the sea and divert the course of the current. We will throw down a section of the chalk-cliff; that will make a mound, on which works of masonry, if necessary, can be erected afterwards.”

This was done about two miles east of Newhaven, by firing an enormous charge of gunpowder in chambers drilled in the limestone. I went over from Brighton to witness it, and the sight was a striking one, as soon as the smoke and dust consequent on the explosion had cleared away. The operation, neatly conducted with an electric battery, proved successful; and its result, in the amount of chalk thrown down on the beach, was judged sufficient for the time.

But for this “piÈce de resistance,” Seaford might by this be in a fair way to furnish to future generations a gigantic specimen of a marine fossil.

The danger to Seaford arose not from storms or any casual visitations, but from the steady continuous action of the tide encroaching on the line of coast where the town stands. Whether the chalky breakwater above described will long suffice to counteract this elemental mischief may be doubted. If after a while it should prove inadequate, the operation will have to be repeated on a larger scale.

The height of the tides at sea is always known; and it varies little, depending upon astronomical causes, chiefly on the attraction exercised by the moon. But on shore, and inland in certain rivers, the case is widely different. Here the land itself, with its rocks and embankments, introduces artificial conditions which influence the local tides in an extraordinary manner. Thus, at Chepstow, by the Castle rock, the rise of a spring-tide is sometimes as much as sixty feet perpendicular. In Mount’s Bay, Cornwall, it is fully forty feet; while in the north of Scotland on the coast, it does not average more than ten.

The tides have other variations beside this of local magnitude; and one of these, which takes place along our southern coast, is interesting and important, but was little known till the Admiralty surveyors went to work. It may be briefly described as follows.

As far as Scilly Isles and the Lizard’s Point, the great tidal wave, which twice in every twenty-four hours flows in from the Atlantic, maintains pretty nearly the same level on the opposite shores; and this continues as far as Exmouth on the Devon coast, and St. Malo on that of Brittany. But when this great wave reaches the “Needles” which form the westerly point of the Isle of Wight, it divides into two very unequal portions. Of these, the southern and larger portion sweeps round the base of the island, passing Freshwater and Chale and Blackgang, and then rounding St. Catherine’s promontory and running up to Dunnose with scarcely-diminished velocity; but the northern and smaller half enters the Solent, and owing, it is supposed, to the resistance of two shores (by friction) to its progress, advances but slowly, and does not arrive at Southampton Water before the other has made Dunnose and is filling Sandown Bay with a back-stream. This causes many differences in the amount of water at almost any given moment on the two sides of the Isle of Wight, north and south; and it gives rise to many curious varieties of tides, real or apparent. In one spot near Shanklin, my attention was frequently drawn to the fact of a partial tide suddenly flowing, for perhaps the space of an hour, during the time of ebb.

But this is not the only “water-company” here at work, nor is the above the only class of phenomena resulting from such agency. Beside the tide-wave there is the Ocean-current, which is quite a distinct thing. This current is due to a branch of the Gulf-stream; and it flows here from west to east, and from south to north. That is to say, after leaving Newfoundland, so much of it as actually reaches Britain would run up St. George’s channel northwards, and up the English channel eastwards. And although the velocity of this current is but trifling, yet, owing to its unceasing action in one direction, its effects are remarkable. Moreover, it is not affected by the waves; whether the sea be sleeping in a calm or tossed with storms, the motion of the current is the same. The only change as yet observed is when its waters come to the surface and have their temperature lowered by a chill wind; for, this gulf-stream is itself a river of warm water, though its bottom and banks are of the same element cold.

Thus, between tide-waves and currents, changes are going on continually both in the volume and the physical constitution of the sea-water. And this, which might at first on a hasty glance look like casual and unimportant variation, when we come to consider it attentively, is found to be an arrangement fraught with wisdom and beneficence; for it insures continual variations of temperature, it attracts the purifying storms, restores the elastic spring of the atmosphere, and provides for weary man a healthy tonic breeze when he rambles along the beach or scales the face of the cliff. Without the motion imparted by the tides, the sea would probably become putrid. Now the tides depend upon the MOON; yet how seldom do we think of her invaluable services, when we gaze upon her pale face! An Italian once told me that he “loved the moon, adored the moon, never tired of looking at the moon.” And the Padishah,[4] I have heard say, prefers “moon-faced” ladies for his soft companions; but I doubt whether either the pensive Italian or the glittering lord of the Bosphorus ever bestowed five minutes’ thought on the mighty phenomenon of the TIDES.

There are other changes in what may be termed the tidal “high-water mark,” due to the lapse of ages, which the sea has chronicled on the face of many a shore and cliff. It is well known that the coast-line, in this and other countries, has experienced many alterations as to its level. In some places, the ocean has apparently encroached upon the land; in many others, it has receded. One striking index of this latter, and which may be implicitly trusted as proving the fact, occurs where the waters have retired from their former level, and have left exposed to view the remains of an ancient beach. Thus, between Brighton and Ovedean, is found what goes by the name of the “Elephant-bed,” because such fossil bones lie among the pebbles in this part of the cliff. The entire stratum undoubtedly was at one time a beach. Similar phenomena have been traced along the coast-lines of Arbroath and Cromarty shires.

Elsewhere, the sea has gained upon the land; undermining the friable sandstone cliffs, and, as it were, melting down the headlands, so as to change the outline of the coast. But in these latter instances, although “terra firma” has given way, it may be doubted whether the water itself has risen. Wherever it has indubitably done so, to the extent e.g. of submerging a village, I should apprehend the presence of volcanic agency.