Nor can we suppose that these rain-chan- | proved by well-established facts. Nor is nels originally debouched at their present it fair to point out the great physical openings; for unquestionably every lime- changes which must have taken place in stone hill has lost huge masses from its Glamorganshire and in Sicily since the precipitous sides during six thousand teeth of the hippopotamus were deposited years. These caves may have opened into in districts "where there is now scarce a other fissures and other caves, till they rill of running water;" for we learn from finally emptied some of their mud and Lyell's subsequent frank admission that bones into holes and corners at different the African hippopotamus is an eminently levels on the side of the valley below. migratory animal, as much at home in the Also they may have had correspond- sea as in rivers. We must regard it as a ing fissures on the opposite sides of val- well-established fact that many extinct leys, for a whole country often has a com- mammalia were coëval with man; but of mon system of fissures; but it does not the first conclusion based on this fact, follow that the valley was filled up, and namely, the enormous time it must have that the bone mud passed from one side required to make these animals extinct, to the other in the age of Elephas primi- Sir Charles Lyell has given no proof genius. Much stress has been laid on whatever. And of the physical changes some of the facts of Brixham cavern:- which have taken place since these cave that it is near the top of a hill where no deposits were accumulated, his evidence stream could now flow; that a pebble of is too shallow, too summary, too little hematite was found in it, of which the argumentative, too much ex cathedrâ, to principal deposit is on the opposite side command our conviction. We do not say of the valley. We know a little of that that he has no better evidence to produce; neighborhood:-the hill is a huge mass of but until he brings forward the better many acres even now; and allowing for evidence, and establishes the certainty of the waste of six thousand years, we may the rate of change manifest in these physafely say it must have been larger and sical alterations, we must regard the antihigher. Any one who has seen the strong quity of the human race in connection gutter-current which runs from a few with cave-bone deposits as "not proven." roods of sloping ground after heavy rain, may judge whether a few acres would not supply water and mud enough to fill up Brixham cavern in no great period of time, and float in bones of dead and limbs of half-devoured beasts. As to the hematite, small deposits of it are not rare in the neighborhood; and one such may easily have lain in the hill itself, without obliging our imagination to take a leap across the whole width of Brixham valley. We do not say that Lyell's other evidence of physical changes can be as readily explained; for he has given us no details of his proof. It is not enough even for one of his authority to say, "I feel convinced that a complete revolution must have taken place in the topography of this district," or merely to observe that the facts of the loess in the neighborhood of Liége imply "the filling up and re excavation of the valleys at a period posterior to the washing in of the animal remains." These facts are the very things which should have been produced; for the time necessary for their accomplishment is the whole point in debate a point not to be thus carelessly asserted or coolly taken for granted, but to be

Perhaps Sir Charles Lyell's long-established conviction prevents his seeing the insufficiency of his proofs; or perhaps he is satisfied to give us very full and clear explanations of the facts brought out by the discovery of human remains in valley alluviums, knowing that the evidence on this point will reäct confirmatively on the less decisive testimony of cave-bone deposits. Let us, then, proceed to examine carefully the proofs of the great antiquity of the human race, derived from ancient valley alluviums.

II. Valley alluviums.

"Throughout a large part of Europe we find at moderate elevations above the present riverchannels, usually at a hight of less than forty feet, but sometimes much higher, beds of gravel, sand, and loam, containing bones of quadrupeds, some of extinct, others of living the elephant, rhinoceros horse, ox, and other species, belonging, for the most part, to the fauna already alluded to in the last chapter as characteristic of the interior of caverns. greater part of these deposits contain fluviatile shells, and have undoubtedly been accumulated

The

in ancient river-beds. These old channels have

long since been dry, the streams which once flowed in them having shifted their position, deepening the valleys, and often widening them on one side."-Page 93.

This is the situation in which, during | that the second and third must be incalthe last twenty years, hundreds of stone culably older. And yet we wrong him: implements have been discovered in the he does not undertake to prove the great valley of the Somme. They are found in age of the present valley-plain, he only remnants of beds hanging like small insinuates it on very doubtful evidence, terraces upon the sloping hill-sides, from and afterwards alludes to it as being "in ten to one hundred feet above the present all likelihood" thousands of years old. level of the river. The flint implements He tells us that the lower part of the are "not in the vegetable soil, nor in the valley is a mass of peat, sometimes more brick-earth with land and fresh-water than thirty feet thick. It contains bones shells next below," where they might be of recent animals closely analogous to supposed to have been buried within the those of the Swiss lake dwellings, and the recent period," but in the lower beds of refuse mounds and peat of Denmark, with coarse flint-gravel, usually twelve, twenty, stone implements of the Celtic period, reor twenty-five feet below the surface." cent shells, trunks of fir, oak, hazel, walnut, Many persons have denied that these etc., and three or four fragments of human pieces of flint are of human manufacture, skeletons. As to the age of this peat, M. and Lyell devotes half a chapter to Boucher de Perthes, having found in it establish the fact a fact which ought certain flat dishes of Roman pottery, has now to be considered indisputable. He satisfied himself that they could not posalso produces ample evidence that these sibly have sunk into the peat because flint implements are found in beds that they were flat: ergo, they once lay on contain bones of extinct animals, with the surface: ergo, the mass of peat above recent fresh-water and marine shells, still them marks its rate of growth since the living (with one exception) in the north Roman occupancy of the country: ergo, of France. The circumstances under we may thus venture to calculate the age which these beds occur is the evidence of of the peat that lies below. But-Lyell their great antiquity. adds the obtained "rate of increase would demand so many tens of thousands of years for the formation of the entire thickness of thirty feet, that we must hesitate before adopting it as a chronometric scale." In other words this calculation is utterly worthless, even on Lyell's own admission; yet this is all the data he has for attempting to estimate the rate of the growth of peat. He has, however, one other argument for its antiquity-the bottom of the peat is many feet, sometimes as much as thirty, below high-water mark; nay, it is thrown up by storms on the French coasts, so that it is plainly lying in part under the sea. This implies subsidence and probable oscillations of level, which, at the rate they now go on, require a considerable interval of time. We do not think these vague suggestions worth much; but they are all Sir Charles Lyell offers in proof of the great antiquity of the valley of the Somme. What does it matter?

They occur chiefly at two levels, both of which may be traced at various points throughout the valley of the Somme: the one but slightly raised above the present river plain, the other from eighty to one hundred feet above it. The latter has been most fully investigated at St. Acheul near Amiens, the former at Menchecourt near Abbeville, where a mixture of marine shells has been found with land and fresh-water remains, "There are, here and there, patches of drift at hights intermediate between the higher and lower gravels;" but as they do not affect the general argument, we need not complicate the evidence by taking them into account. Now, as a general rule, when there are alluvial formations of different ages in the same valley, those which occupy a more elevated position above the river plain are the oldest." The river must have deposited them before it cut its way down to the lower level. Here, then, are three different formations, bearing witness to three different periods: first, the present valley-plain of the Somme through which the river now takes its course; secondly, the lower level gravels; and, thirdly, the higher level gravels. Sir Charles Lyell undertakes to prove not only that the first must be very old, but | Page 112.

"Whatever be the number of centuries to

which they relate, they belong to times posterwhich we are next to consider, and are even ior to the ancient implement bearing beds separated from them, as we shall see, by an interval far greater than that which divides the earliest strata of the peat from the latest."—

The evidence of this interval must be (but they do not contain flint tools. Near sought in surrounding facts. Here is Bedford also, and at Hoxne and IcklingLyell's statement-that at Menchecourt, ham in Suffolk, there are deposits of graand also on the opposite side of the river, vel, containing flint tools and bones of the beds of alluvium are about twenty- extinct quadrupeds, which are thirty feet seven feet thick, and they lie about ten above the present drainage lines of the or fifteen feet above the present surface country. Therefore, we must regard the of the valley; that is, from forty to forty- alteration in the water level of the valley five feet above the bottom of the valley; of the Somme as a fact corroborated by for we must remember that the peat is many similar changes, though the amount thirty feet thick. There must have been of that alteration is exceptional. There is time to deposit these beds, time to elevate one more item of evidence. In the upperthem, and time for the river to cut down level beds of the Somme and Seine there the valley forty feet. Also, these beds are contortions in the strata which clearly contain the bones of extinct animals, and resemble those produced by ice-action; a shell now found only in Asia; there immense blocks of rock also, lying in the must have been time gradually to ex- alluvium, and brought from distances betinguish the animals and to change the yond the power of water transport, sugclimate. Also, in the beds of Menche- gest the agency of ice. In such facts we court a fluviatile formation underlies a find hints of great alterations that have marine one, from which we judge that taken place in the climate of the North of the river first prevailed, and then the land France. subsided: both fluviatile and marine beds are now raised above the present valley, from which we judge that there was a subsequent elevation; after which the peat beds of the present valley began to grow, and, as these are now found beneath the sea, there must have been a second subsidence. All these changes happened since the deposition of the lower gravels; and, at the rate at which such changes now take place, they imply an enormous lapse of time.

But this is nothing to what follows. The beds at Menchecourt are raised but little above the present valley: what are we to say to the higher level gravels which occur in the valley of the Somme from eighty to one hundred feet above the river, containing bones of extinct animals and flint implements? If the lower gravels are so very old, what amount of time are we to add for the elevation of the higher beds, and the cutting down of this great valley to its present level? Lyell does not go into much detail of evidence here; but rather leaves the fact in all its magnitude to speak for itself.

According to our present knowledge the hight of these upper level gravels of the valley of the Somme must be regarded as exceptional. In the valleys of the Seine, the Oise, and the Thames, beds are found containing flint tools and bones of extinct animals, slightly raised above the present river courses; and in the valley of the Seine high level gravels are found,

This is Sir Charles Lyell's case in defence of the antiquity of the human race. This is the whole of his argument; he stands or falls by this. Like a lawyer who will say all that can possibly be said, he has strung bad and good pleas together; and we must strike some off the list in order to weigh justly the force of those which remain.

In the first place, his figures are not as exact as they ought to be. After giving us to understand that the Menchecourt beds are ten or fifteen feet above the river, he tells us that higher deposits at Abbeville are fifty feet above those of Menchecourt, and one hundred feet above the Somme. Then we are told that the peat is thirty feet thick; but is this uniform thickness? We remember that he says the gravel in Brixham cavern is bottomless at twenty feet; and so it is in certain deep holes; but not that, nor anything like that, in the average thickness of the bed.

Secondly, the fact that flint implements are found beneath soft alluvial beds is no proof that they are more ancient than those beds; neither is the juxtaposition of a stone hatchet and an elephant bone any proof that the two were contemporaneous. Geologists are rightly very jealous of evidence drawn from the disturbed beds of river courses. On this point we must quote the remarks of Mr. Geikie on some ancient canoes found in alluvium at Glasgow, and which Lyell himself pronounces "very judicious."

The

Again, we must not reckon the time it would have taken for the river to cut down a whole valley through the solid chalk; for we do not know that the solid chalk was there to be cut down. valley might have been formed ages before, and filled with earlier alluvium, which would have readily yielded to water action. Nor are we to count the time necessary to raise the bottom of the valley (now covered with peat) above the level of the sea; for a river's mouth choked with sand-banks and lined with marshes is the very place where peat would most rapidly grow.

"The varying depths of an estuary, its banks | lence over the sea, and of subsequent subof silt and sand, the set of its currents, and the sidence, that a fluviatile bed should underinfluence of its tides in scouring out alluvium lie a marine one; for in the same esfrom some parts of its bottom and re-depositing tuary a tide current will prevail in one it in others, are circumstances which require to be taken into account in all such calculations. part, and a river current in another, and Mere coincidence of depth from the present sur- these will sometimes be exchanged and face of the ground, which is tolerably uniform reversed. in level, by no means necessarily proves contemporaneous deposition. Nor would such an inference follow even from the occurrence of the remains in distant parts of the very same stratum. A canoe might be capsized and sent to the bottom just beneath low water mark; another might experience a similar fate on the following day, but in the middle of the channel, both would become silted up on the floor of the estuary; but as that floor would be perhaps twenty feet deeper in the center than towards the margin of the river, the one canoe might actually be twenty feet deeper in the alluvium than the other; and on the upheaval of the alluvial deposits, if we were to argue merely from the depth at which the remains were embedded, we should pronounce the canoe found at the one locality to be immensely older than the other, seeing that the fine mud of the estuary is deposited very slowly, and that it must therefore have taken a long period to form so great a thickness as twenty feet. Again, the tides and currents of the estuary, by changing their direction, might sweep away a considerable mass of alluvium from the bottom, laying bare a canoe that may have foundered many centuries before. After the lapse of so long an interval, another vessel might go to the bottom in the same locality, and be there covered up with the older one, on the same general plan. These two vessels, found in such a position, would naturally be classed together as of the same age; and yet it is demonstrable that a very long period may have elapsed between the date of the one and that of the other."-Page 50.

Of the tendency of heavy bodies to settle down in alluvial silt we find a notice in The Geologist, for January, 1861.

"In the course of making the excavations for the Thames tunnel, the difficulties that arose from the nature of the soil in some parts, induced the contractors to procure a diving-bell, for the purpose of examining the bottom of the river. On the first inspection, a shovel and hammer were left on the spot by the divers; but these tools were, contrary to their expecta tions, nowhere to be found on their next visit. In the progress of the excavation, however, while advancing the protecting wooden framework, this missing shovel and hammer were found in the way of it, having descended at least eighteen feet into the ground, and probably resting on or mixed up with some ancient deposit."

Nor need we include the imaginary ages requisite to change a very cold climate (evidenced by ice-action) to a much warmer one, (evidenced by an Asiatic shell,) and then back again to that of temperate France. The ice-action is a mere conjecture, which is not confirmed by the presence of any specially Arctic shells; and, even if it were more probable, it would be quite as fair to weigh the two facts together, and conclude that greater heat and greater cold united in a climate only removed by its want of equilibrium from that of France at present.

Yet if we clear away all these questionable conclusions that array themselves round the evidence, and make it look more imposing, there still remains the indisputable fact that there was a time within the human period when Picardy was a hundred feet lower, or the Somme a hundred feet higher than it is at present; and this great valley (average width one mile) was filled up to the level of the higher terraces at St. Acheul.

"The mere volume of the drift at various hights would alone suffice to demonstrate a vast lapse of time during which such heaps of shingle, derived both from the eocene and the cretaceous rocks, were thrown down in a succession of river-channels. We observe thousands of rounded and half-rounded flints, and a vast number of angular ones, with rounded pieces of white chalk of various sizes, testifying to a prodigious amount of mechanical action, accompanying the repeated widening and deepening of the valley, before it became the Again, it is no proof of a river's preva-receptacle of peat; and the position of the fliut

One who is not a geologist may reply, "And is not six thousand years enough to effect all this?" No, certainly not, if the growth of peat, and the action of water, and the forces of elevation and subsidence, and the rates of erosion and deposition, are to be calculated according to Lyell's averages. But it is to this we demur. Even for the present time we have scarce-present. Put this in plain words, and ly data enough to strike fair averages; but, when we begin to investigate phenomena of the past, every question of time must wait on this preliminary questionAre past rates to be calculated by present rates of change?