CHAPTER VIII.

[3]“Mémoires de l’Académie des Sciences.” Anno, 1721.

PNEUMATICS AND HYDRAULICS.—POWER OF THE WIND.—POWER OF THE WAVES, AND VELOCITY ACQUIRED BY THE WATER.—OCCASIONAL HEIGHT OF TIDES.—TIDAL WAVE.—CURRENTS.—TIDAL PHENOMENA ON THE ISLE OF WIGHT.—VARIATIONS IN THE COAST-LINE.

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 beenflooredby an unexpected billow while bathing. I always made this reflection at the moment: “Its power is not known: it has flooredmeeasily 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 pieceswithin seven minutes! Yet, what a delicate thing is AIR! What a yielding thing is WATER! But then the air and water threw heron 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 theroar of the thunder; and water is almostincompressible, and therefore its blow will knock downanything.

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 ismaking, 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 longon the sideof a wave, changes its form from that of an upright ridge (i.e.withverticalaxis) 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 itsvelocityhas been enormously increased, while itsbulkis 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 anoscillationof 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 themotionwhich is propagated, and, as it were, handed on, like an electric shock through the successive plates of a battery. Now thismotionincreaseswith 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 equalsseventy 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 thebreakers, 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 theIrish 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 yetunbrokenwave, 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 groundvibrateapparently, though the sensation is probably electrical. But let any one consider the conditions of the wave cited above, and reckon what isthe force of the blowat 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 wasutterly unableto 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 couldnot; 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 thestrokeof 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 fragmentafterwards, 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,tillsomething saluted those nearest the beach, which rendered a retreat imperative. This was not the salt spray, nor the rattlinghail neither, but a cloud of “skirmishers” in the shape ofpebbles and gravelfrom 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 sidelongdragof 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 anelectric 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 assixty feet perpendicular. In Mount’s Bay,Cornwall, it is fullyforty feet; while in the north of Scotland on the coast, it does not average more thanten.

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 (byfriction) to its progress, advances but slowly, and does not arrive at Southampton Water before the other has made Dunnoseand is filling Sandown Bay with aback-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 suddenlyflowing, 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 thetide-wavethere 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 iswhen its waters come to the surface and have their temperature lowered by a chill wind; for, this gulf-stream is itself a river ofwarm water, though its bottom and banks are of the same elementcold.

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 strikingindexof 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 ancientbeach. 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, meltingdown 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 hasrisen. Wherever it has indubitably done so, to the extente.g.of submerging a village, I should apprehend the presence of volcanic agency.

[4]Sultan, “Father of the Faithful.”

GEOLOGY LIES AT THE BOTTOM OF EARTHLY THINGS.

There seems to be no strong reason for doubting that every elementary substance of which we have any knowledge wasseparatedat the first from that crude mass called “the earth,” and which, along with “the heaven,” God created in the beginning.

For, after that first assertion, we read of continued acts of “separation” by an Almightyfiat. Thus light is separated from darkness; waters from waters; water from earth. And by a like analogy we may suppose that the “firmament” or atmosphere, the lower part of which we breathe, was also eliminated in its component gases from the primitive shapeless bulk of matter.

If we take forty-five miles as the average height of this atmosphere above the surface of our globe, it is proportionately, like the thin rind upon an apple, or the bloomupon a peach; and may very well have come forth without any violence done to nature, or any waste of her resources, from the womb of the earth.

OXYGEN is a gas universally diffused, for without a large supply of it human beings and all the mammals, birds, and reptiles, would die. But oxygen is not a moresimpleelement than CARBON or SILICON; and silicon is almost as universal, for it enters largely into the composition of all known rocks, excepting coal, limestone, and rock-salt.

Then, beside silicon and carbon, there is BORON, and many others, all of which will combine permanently with the principal gases, and which we may, therefore, fairly suppose did so in the beginning.

The oxygen which we breathe enters into composition with almost all known substances. It constitutes about one-fifth of the atmosphere, perhaps eight-ninths of the water, and helps chemically to compound all forms of earth and rock, and all the metals save five. Now this proclaims at once akindredelement, and does not look like a substance made independent of all the others at the first. Evenpotashandsoda, which were long called “fixed alkalis,” having resisted all attempts to decomposethem, yielded at last to a galvanic process, and were found to be compound; oxygen, in both cases, having united itself intimately with a metallic base.

It is probable, therefore, that every substance which we can handle, or of which we can recognize the presence by a chemical test, was as truly a part of the chaotic Earth as was the clay or the granite. The gaseous atmosphere or “firmament” was eliminated by an act of creation from the torpid mass, the waters were drawn off and gathered together, the rocks consolidated, the metals precipitated, most of the crystals were probably perfected by galvanic operations. But there is nothing, from the crystallized blocks of the mountains to the salt held in solution in the sea, from the heavy rain-cloud which darkens the sky to the gossamer films of vapour which fringe the outermost edge of our atmosphere, which was not actually present as an existing particle when the Earth, “Mother-Earth,” was made. And the EARTH, as we see, could very well furnish all these concomitant and subsidiary elements, without being impoverished at all. Indeed, as far as experiments and investigations proper have gone, we have as yet only touched thesurfaceof our globe. The deepest mine which men have ever sunk into the bowels of the earth bears in its depth the same proportion to the earth’s radius, as aline, or one-eighth of an inch, bears to the height of the monument at London Bridge. Some of the exposed strata of rock, allowing for thetilting-upof their edges, certainly reveal a deeper sample than this; but still, it is like the prick of a pin on the hide of a rhinoceros; it does not even penetrate the creature’s folded hide; but of what lieswithinit tells us nothing.

Mr. Baily’s successful attempt at “weighing the Earth,” which, with consummate patience and skill, he brought to a termination in his house in Tavistock Square, has established the physical fact that this planet is not “a hollow sphere,” as some persons had supposed, butsolid, probably to its very centre, and of considerable specific gravity. Here is a mighty mass of Matter; it may be, as Dr. Whewell has argued, thegreatest mass(in solid contents) in our Solar system. What do we know of its interior construction, economy, and arrangement? Nothing, except that all obey thelawsestablished by the Creator, whether those of gravitation, cohesive attraction,or chemical combination. The “statistical report” is wanting, especially in such departments as those of the Trap and Volcanic lavas.

The amount of SALT in the ocean is a circumstance which geologists have not, I think, sufficiently considered. This salt, if precipitated, would, it is believed, yield a solid range of mountains equal to that of the entire Himalaya. Now, mighty rivers run into the sea, as those of La Plata, Amazons, Mississippi, St. Lawrence, Orinoko, and many others; butnone of these rivers are salt; they are enormous bodies of fresh water. How, then, does the ocean maintain everywhere its saline character unimpaired? not to ask, whence did so much salt come? There is, indeed, a hill of salt in Spain, and there are mines of rock-salt in Poland and Hungary; but theeffortwhich was made, so to speak, when the proportion now existing in the ocean was squeezed out of the huge terrestrial sponge, must far have exceeded that of any subsequent addition or contribution.

The ocean itself, asgirdingthis globe, is a prodigious mass of water, indeed. But, if we remember the size ofthe globe itself, as given by its diameter, Ocean appears like a rain-pond. For, if we call its average depth five miles—and it cannot be more than this, may be much less—such a watery envelope would be represented in its proportion to the solid sphere which it surrounds, by a coating of varnish of the thickness of this paper lying on a globe which is twenty feet in diameter.

The COAL-MEASURES are also a remarkable item in the list of substances met with in beds and ranges, and claiming to be considered as rocks—for the coal is apetrifaction, perhaps a partialcrystallization—but due to the deposition of vegetable matter, subjected afterwards to enormous hydrostatic pressure. We have no true estimate of their amount as yet, for fresh mines are being continually discovered; but here seems to consist the chief proportion of CARBON, as developed in this part of the visible creation.

CHALK constitutes one-eighth part of the crust of this globe. The mass of this must have been thrown upat once, when the atmosphere was eliminated, and the waters separated, and the sphere became condensed and solid. It is a “carbonate of lime” in its chemical description,and there is abundance of the limestone-rock all over the world; but it is very difficult to extract from this, in any quantity, the soft, friable, slightly unctuous mineral which goes by the name of chalk (Latin, “calx”).

The METALS exist in the rocks, generally some distance down in the earth’s interior. Their amount, in some instances, is very great indeed. The only one which is rarely met with on our globe, and then in small grains, is the NATIVE IRON,i.e.iron in itspurestate. This want, however, could not have been recognized if we had not happened to find the substance in question in those blocks of meteoric iron, and in the small meteoric stones which have, from time to time, fallen to the surface of the earth during atmospheric storms, and, probably, owing to astronomical disturbances. For, of the iron, in its mixed conditions of different ores, we have an abundant supply. It is a singular fact, that thenative gold, both in pure grains or flakes, and in solid “nuggets,” appears now to be the more prevalent form of that ponderous and imperishable substance. The ranges of quartz-rock in many chainsof mountains are certainly thickly sown with seeds and nodules of fine gold.

I may mention here, as an interesting circumstance to mineralogists and collectors of fossil pebbles, that the “native iron,” which is so scarce on the surface of the ground, is met with, from time to time, along withmanganese, in the heart of siliceous pebbles. But I have never seen it where there is not the presence of some animal organism.

Now all thesesolids, gold, iron, chalk, coal, salt—and I select incongruous items on purpose—are as truly portions of the earth’s mass as are the granite and slate, the sandstones and clays. Andso are alsothe flowing waters and the suspended clouds; andso are alsothe component elements of these—oxygen, hydrogen, and the rest. It is, all of it, MATTER; it all obeys the law of gravitation, and it needs just as much to be taken into account, in a geological scheme or system, as the upheaving of granite rocks, the flux of lavas, or the icthyolite beds amidst the semi-crystalline ranges of the Old Red Sandstone formation.

Consequently I have found, as has partly I trust beenshown in the preceding pages, that even to handle and pronounce upon a pebble, such an one as we can pick up on the sea-shore any summer’s day,all these elementsmust be taken into the account.

In a “moss-agate,” for instance, I discover—

First.A sandy cuticle, which we will rub off, as it is like the dust on your drawing-room table, a real thing, but out of place.

Secondly.Siliceous matter.

Thirdly.A purer form of this in chalcedony.

Fourthly.The “moss,” which is a metal proper, tinged byoxidation. [N.B. Here is oxygen inside a pebble!]

Fifthly.The whole or a part of some extinct animal’s petrified structure.

Sixthly.One thing more,sometimesa drop of water.

Seventhly and lastly.Air, permeating the stone in fine pores and channels, one of the largest of which was in some cases a breathing-hole used by the zoophyte before he drew his last gasp.

Who shall therefore say that a PEBBLE from the sea-shore has nothing remarkable in it or about it, merely because the passing schoolboy can pick it up if he pleases,and, without looking at it for a moment, can fling it at the head of a gull, or dash it to atoms against a larger stone? It is a microcosm in itself; and if it lead us on to further inquiry and patient thought, it will amply repay our trouble, though wehaveloitered away a summer morn or an autumn evening among the Pebbles of the Beach.

GUESSES AT THE PROBABLE FEATURES OF A PAST SCENE.—WHAT WAS THE EARTH’SCOMMENCINGROTATION.—LAW OF THE TIDES AT SUCH A TIME, AND CORRESPONDING ACTION OF THE SEA UPON THE LAND.—ORIGINAL CHARACTER OF THESE FOSSIL FORMS.

Whatever may be thought of the apparent scope or tendency of some of the geological theories which are rife in the present day, no person who has really considered the subject in its principal bearings has any doubt that the surface of our globe, both as to the land and the water, was once very different from what it is now. All sound argument must allow this to be possible: all careful investigation pronounces it to be the fact.

There are potent “menstrua” and mighty furnaces in the laboratory of Nature; and while the actualamountof MATTER in existence has, we suppose, never varied since the original creative act which gave birth to “the heaven and the earth,” the conditions, sensible or chemical, under which that matter presents itself have altered from century to century and from moment to moment.

It is impossible to deem otherwise, if we believe that the “laws” which are established now in this creation were established then.

Let us take, for instance, the law of Universal Gravitation, that law by which the heavenly bodies move in their orbits, and a seconds’ pendulum measurestimeat the surface of our Earth.

We feel assured that this law has never varied; but it is almost equally certain that it must havebegunto operateunder different conditionsfrom those which obtain at this day.

Newton, who always maintained that the commencing axillary movement of the Earth was due to an impulse from the hand of the Creator when He launched it into space,[5]and who declared that without this he could in noway account for its having rotatory motion at all, was nevertheless willing to allow that the time occupied in the first rotation may not have been, as now, twenty-four hours, but possibly an entire year. And as the Earth, once projected, would fulfil, according to the Law of Gravity, the conditions of “a body falling through space,” we find that taking the nth term (2n-1) of the arithmetical series … 1. 3. 5. 7. … (2n-1) … where the successive terms represent thevelocitiesacquired in successive annual periods, about 183 such terms must elapse before 365 rotations would be accomplished within the space of one year, or, in other words, the rotation of the earth bediurnal, as at present. This point of speed once reached, the centrifugal and centripetal forces balanced one another, and the axillary movement became steady.

Of course, in the above hypothesis, the assuming of one year for the first period is arbitrary; it may have been more, it may have been less; but within certain limits there is no absolute reason for supposing that it was a span of twenty-four hours, as now.Revelationnowhere asserts such a dogma.

Supposing, then, amid confessed ignorance as to how the fact stood, that the Earth’s early times of rotation were far longer than now, and taking, say,one yearas the first period, how would this influence other features in a scene which has now long gone by? How would it influence the Tides of the Ocean?

Assuming a correspondingly slow motion of the Moon in her orbit, we should, it seems, have in the lapse of the first yearonerotation of the Earth andtwo Tidesof the Ocean; in the second year,threerotations of the Earth andsix Tidesanswering to them; and so on.

Now these flowing Tides would, in fact, have been vastinundations, the sea rising steadily for many months together; and in like manner the prolonged ebb which followed upon each flood would have given rise to asubsidenceand to the deposition of such particles of mud, lime, silex, &c., as the waters then held in solution after their visiting the higher land.

And thus we see at once, without going further, that the agency exerted by the ocean in ancient times may probably have been different from and greater than anywith which we are now actually acquainted, save in the account given to us, in the inspired Record, of the Deluge in the days of Noah.

When such mighty agencies were in operation, it is not unreasonable to suppose that great changes took place in the way of partial extinction of animal life, and the substitution of new forms to fill up the apparent gap left by the perishing creatures. The contents of the upper chalk, of the greensand, gault, and sandstones, as has already been observed, point to such revolutions and cycles in the history of animated nature.

MAN, who is himself an evident exception to all this, may perhaps,asan exception, be said to prove that such had been the rule. For, it must be remembered,allthe creatures were pre-Adamitic. Not only those vast saurians and mammals, whose fossil remains we have exhumed, and cannot contemplate without wonder, were prior to our race in their actual possession of the domain of the earth’s surface, but every bird, reptile, fish, and zoophyte were certainly made before the man. Now, as the man came last in order, but first in dignity, created in his Maker’s image, and endowed with dominion over all the works of His hand, there was no longerplace or argument for extinction, substitution, or change, among the creatures.Deathwas excluded, and could not enter into the world, unless by a moral delinquency of the chiefest creature.

But already it is probable, although he perhaps knew it not, Man stood, even in the day of his innocence and happiness, in the midst indeed of a blooming creation, but upon the crust of a fossil world.

Moreover, we know from Scripture that minerals find metals abounded; so that the presence of these near the Earth’s surface ought not to be referred (as by some they have been) to the epoch of Noah’s Deluge. “Gold and bdellium and the onyx-stone” were already in the “land of Havilah;” and Tubal-Cain was “an artificer in brass and iron,” which must therefore have been exposed in veins of the upper rocks.

And if the Earth already showed her nuggets of gold and lumps of onyx, it is not likely that she was deficient in beautiful fossils. Certainly, such substances as manganese and native iron did not find their way into the heart of siliceous pebbles inmoderntimes.

But it by no means follows from the above, that allthese fossil forms belonged to creatures whose species are wholly extinct. Indeed, in some instances, this cannot be allowed for a moment. Probably, the “choanite” is extinct. I doubt whether the “ventriculite” be so. Dr. Mantell was pleased to assume that this last-mentioned zoophytegrew—like one of the “mushroom” class of plants—rooted to one spot. There is no evidence for this whatever, and my impression leans another way. In the class of marine “Acrita” termedAcalephæ, there is a family which bears the name ofRhizostoma. These animals are composed mainly of a large, mushroom-shaped, gelatinous disc, and of a supporting central pedicle. In structure and function this latter organ much resembles the root of a plant; and, no doubt, it absorbs nourishment by seizing upon the minute animalculæ which abound in the water where the “rhizostome” is floating about. The entire animal is very like a toadstool, or “agaricus,” in form; but for all that, he does not grow, as a plant, in one spot, but is always sailing about by means of his large disc above-mentioned. His general appearance closely resembles that of a “ventriculite” from the flint; and I think it a probable guess to assign them to the same species.

The “branching alcyonite,” on the other hand, did, I imagine, grow, like a Coral or “Encrinite,” in one place; and I suppose it was much like an ice-plant in form, but that it had the power of drawing back at will all its branches and suckers—which were, in fact, the creature’s arms and tentacles—into the root or bulb which formed its base. The “sponges,” a large family, we know are not extinct; and the conformation of the living individuals fully bears out all the marvels which have been predicated of the fossil animal. I have handled these creatures, fresh from the sea, at Brighton; and I had an unpleasant consciousness, while holding one in my hand, that the round, greenish, jelly-like bush was only hishouse; but that the gummy fluid, which held possession of it after squirting out the sea-water, was the individual himself, though independent of the accessories of bone and muscle. This kind of “sponge” floats about: there is another, well-known among submerged rocks, which is fixed, and grows. I believe the fossil specimens to have belonged to the migratory class.

I once picked up, near Hove, a pebble which contained a fragment of the lungs of a tortoise; the elevated ridges, and depressed pulmonary cells, appearedto have left their peculiar structure in the flint. I have mislaid this specimen, and so cannot give a sketch of it here.

The “holothurida,” or “sea-cucumber,” is found occasionally in the Isle of Wight, beautifully fossilized. A specimen was shown to me, from the beach near Chale; it was avariety, but unquestionably of this class of animals.

A fossil, figured in one of the “chromo-plates” to this volume, has obtained the name of a “troglodyte;” I do not know why. I suspect it was one of the “asteridæ” when alive, but that in the death-struggle, the long arms collapsed and twisted together.

I have frequently found what I believe to have been some such organ as the stomach of a star-fish in the centre of hard pebbles. The form was always pentagonal, like the corolla of certain flowers pressed flat.

The “myriapod,” depicted in Plate V., I should at once conclude to have been a marine insect, answering to some of our “scolopendridæ,” if theheadwere not lacking. But since the back or spine in this fossil is all in one piece, and there are no lateral plates or divisions for the several pairs of feelers, it may be, inaccordance with such a frame, that the head fitted on without the apparent juncture of a neck; and if so, this may be an entire insect. It is right however to add, that I feel some doubts about this.

The Plate VI. contains a figure of a fossil to which I have attached the name of “Spindle-choanite.” In fact, the specimen, until cut in twain, was fusiform; and, I have no doubt, a complete animal.

The choanite from Eastbourne,uncut, Pl. IV., portrays a creature who, I think, expired in a vehement struggle. This would keep him on the surface of the siliceous flood; and it would harden, for the most part, beneath him, leaving his limbs sprawled out on the top of the pebble, as now seen. The beautiful “pyriform” specimen, Pl. VI., shows a similar struggle, amidst liquid agate and manganese. In the large Actinia, or “star-choanite,” portrayed in the frontispiece, the happy animal died quite quietly; and that is why his fossil mummy is of such a noble size and development.

The figure called “Nondescript,” Pl. IV., I do not think represents any complete animal, but a part of the organization of one. I have traced its likeness, in the “Animal Kingdom,” by T. Rymer Jones; and think itnot improvable that a woodcut at p. 364 of that most interesting volume depicts, in thearmsof one of the “Brachiopoda,” in that “calcareous loop” with its curved “crura,” the exact structure which, in the living animal, served to open or shut the bivalve shell, but in the fossil specimen looks like a miniature-painting on ivory, to perpetuate some curious organism in the liveliest colours of the pallet. “Terebratula Chilensis” is Mr. Rymer Jones’s animal; and in the very vicinity where I found my fossil in question, I have since obtained, in a flint pebble from the cliff, a beautifully petrified “Pecten” (same species of shell) in agate.

I might multiply remarks and instances such as these; but it is not needed. Every one will form their own opinion, in collecting fossil pebbles, as to what theoriginalswere; but I think they will generally agree with me, that while our living individuals differ in many points, still we have mostly types of the same species actually existing in our present seas.

What all connoisseurs, and even amateurs, should do, is to preserve every remarkable specimen they may obtain, along with an accurate note of where they gotit. It is a great pity that, among so many persons who have at once discernment and a liking for this branch of Mineralogy, there are so few who will be at the trouble of what lawyers call “taking minutes” of the evidence which comes before them in the course of the pursuit. I have looked over several fair enough collections made by amateurs; but, with one exception, I never knew an instance in which the collector could tell me, with any degree of certainty, from what particular beach he had gathered this or that specimen. Of course, when a scientific investigation is proposed, such omission renders the most valuable part of the collection comparatively useless. For the locality is all-important. A pebble may thus be always traced to its geological “home” or birthplace. It can only have had one of three sources: either it was first droppedhere, where you find it; or, it is a “travelled” pebble, having come round from some distant beach; or, it is an offering from the deep sea. The latter case is of exceedingly rare occurrence, and need hardly be taken into account; nevertheless, for truth’s sake, and to include all possible varieties, I cite it here.

A genuine deep-sea pebble is a waif which I have onlytwice, as yet, met with in my sea-side experience. One of these was, I think, fished up in a dredging-net; the other was thrown on the beach during a storm. In both instances, the fossil was a “choanite,” and bore the marks of having been washed out of a limestone rock. The age of such fossil could not have been less than 4000 years, the date of Noah’s deluge, for obvious reasons; but it may have been considerably greater.

If there were any known method of softening these pebbles to a consistency like that of melted glue, we might learn something concerning their past history; but I am not aware of the existence of any such process at present.Silex, once hardened into the condition in which we meet with it, is a most intractable substance to deal with; and the very fact of its having at one time been viscous, renders it highly improbable that, in the course of nature, its texture will ever assume a plastic character again. Moreover, while the majority of our flints are concretions, there are some which are semi-crystalline. These latter, it is evident, cannot now advance to the stage of perfect crystals; but neither can they retrograde: the next change which awaits so hard a substance must be, to crumble away.

Sometimes, on our beaches, hollow globes of flint are picked up, which, when you break them open, are found to be full of a white, powdery substance, like the chemist’s magnesia. This is much the same as the “rock-milk” of mineralogists, a very fine deposition of lime, occasionally met with in beds of the chalk strata, and considered to be a result of some filtering process, when the water, after being long pent up, had escaped by small crevices. But in the flint-globes no such straining can have taken place; and in sundry specimens which I have examined, I generally came to the conclusion that some conchiferous animal had been inclosed in the nodule, and his shell had afterwards broken and been pulverized. Sometimes I found within the “rock-milk” a dark-brown, carbonaceous spot; this would be the creature’s body, as Dr. Mantell supposes of his “molluskite.” The cavity is never quite filled up. I imagine many of these “powder-horns” to be altogether modern in their date.

A much more curious phenomenon than the above occurs from time to time in solid agate-pebbles, which, when picked up, are found to contain in a centralchamber, visible to the eye, a drop of water. These are scarce, and fetch a high price at the museums. As much as twenty pounds has been more than once given for an undoubted specimen. How the above-mentioned singular effect was arrived at, has, I believe, never been explained; at least, not so as to satisfy a close reasoner. The samelusus naturæis met with, I think more frequently, in rock-crystal and in the dark fluor-spars.

The last apparent animal organism which I shall notice, as having more than once occurred to me as apossibleexplanation of the patterns disclosed in certain sections of agate-pebbles, is that of some creature’s “ovary.” The eggs of the whelk, and those of the cuttle-fish, are deposited in clusters, like some of the “grapes” on sea-weed. I have found, in some of the Isle of Wight pebbles, a conformation closely resembling this, but on a much smaller scale. That the original substance was part of an animal, I have no doubt whatever; and the arrangement of the lobes or spherules, composing the mass, more resembles that of the spawn of the above-named fishes than anything else which I am acquainted with. Still, resemblance is not identity. The thing may be only a curious coincidence,resulting from some unexplained freak of nature; as when she carved the profile of Napoleon’s face in the outline of a part of Mont Blanc, and also (quite as distinctly) in that of a hill which overlooks the town of Belfast.

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