THE ANCIENT THAMES:

ITS ZOOLOGY, CLIMATE, AND CHANnel.

CHAPTER I.

INTRODUCTION.-THE THAMES A MEMORIAL OF AN EARLIER WORLD.MODERNNESS OF ITS HUMAN HISTORY.-EVIDENCES OF ITS ANTIQUITY.-THE THAMES ITS OWN HISTORIAN.-THE BED OF THE RIVER A NATURAL MUSEUM. THE THAMES OF TO-DAY AN AQUEDUCT AND NOT A NATURAL STREAM.-VIEW OF THE OLD EMBANKMENT AT DAGENHAM.-THE ANCIENT RIVER: CONTINENTAL PERIOD OF ITS HISTORY.-STRANGE ZOOLOGY OF THE TIME. THE THAMES MAMMOTH AND RHINOCEROS: A VISIT TO THEIR GRAVES AT ILFORD.-CHANGES IN THE GEOGRAPHY OF THE THAMES VALLEY SINCE THE MAMMOTH PERIOD.

ONDERFUL in the annals of Nature around London is the history of the River Thames! Strange is the tale that our homely but ancient stream can tell us of the early phy

sical condition of the land through which it flows! How many of us have thought to trace to its origin in time the familiar Thames of to-day, and to find in it a link with the beginning of terrestrial history in England! Too commonly the Thames is supposed to derive its sole interest and charm from its association with man and his fortunes. It is natural that the Thames of the poet and the painter, the haunt of the Muse and the shining feature in the landscape, the parent of commerce and civil life, glistens never too often for any of us in the pages of our national literature. But the charm which the Thames possesses as the companion and reflex of man need not leave us in contented ignorance of the story it tells of itself, and of the country through which it flows, before it entered

the annals of Britain and became a river of human history. The tale of the River Thames, as told by itself, is that of a grand memorial of an earlier world. It takes us far back in the "speechless past" of our country's terrestrial history. We shall not fail to be rewarded if we turn for a time from the human aspects and associations of the river to the story, stranger than fiction, that the valley and its deposits contain. We shall learn for ourselves the records of a climate and zoology that belong to a departed age. We shall share with the geologist the knowledge that

Where fashion on her gay parade assembles,

The Mammoth and Rhinoceros have strayed,
Treading beneath their feet Old Ocean's races.

country that drains

If the geological tale of the Thames is wonderful and romantic, the records in which we may read it are original and authentic. From the first the Thames has been its own historian, and the historian of the country through which it flows. From the first it has preserved in its channel the memorials of the itself into its valley. Far back in "old dusky Time," its bed was becoming a natural and chronological museum for the instruction of a human world. It is thus that the autobiography of the Thames is read alike by the labourer who to-day digs up the bones of gigantic quadrupeds in the deserted bed of the stream, as well as by the student of Owen and Lyell in the library or geological collection.

Far different from the Thames of to-day was the Thames of uncivilised England and geological antiquity. In these, its declining years, the mighty creature has fallen captive to man. With shrunken bulk and in a narrower channel the Thames now winds through placid and fertile landscapes an imprisoned and harmless course. To-day it is the tamed and subservient minister of a human world. But the ancient river has left to us, in its wider and now almost deserted bed, memorials of the vaster energy and huger volume of its youthful and meridian years. In the broad valley it has gradually excavated for itself by the continuous passage of its waters, the Thames reveals to the ordinary eye the great achievement of its earlier ages.

From the deposits the old river has

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preserved in its bed, we learn something of the atmospheric and physical conditions of the period in which the excavation of the valley proceeded. The vast accumulations of gravel and sediment that now stretch for miles on either side of the river, tell us of the wider and more vigorous stream from which they were deposited. They afford us, too, a vision of the Thames in the remotest ages of England's history. We see it as a terrible and devastating creature in the landscape, and not as now the captive and servant of man.

The Thames of to-day: an Artificial River reaching the Sea by an Aqueduct.

We shall the more easily read with the geologist some of these wonderful memoirs of the ancient Thames, if we realise to ourselves how artificial a river is the Thames of to-day. A steam-boat ride from London to Kew, or from London to Erith, suffices for our purpose. It enables us to see even in these modern days how slight are the barriers which withhold from our view one of the wildest aspects which the Thames Valley of primeval England presented. As we traverse the river we observe with a new significance the embankments which imprison the waters, and conduct them down to the sea. The dense and spreading forests and the gigantic mammalia of the early Thames-country are indeed missing, but how soon the wide waste of waters which once shared the landscape with them would return to its old familiar bed were the river released for a day from the restraints which man has imposed! is these old embankments of the Thames that daily save the prosperous and populous valley from the wasteful spread of the river and the incursions of the sea- -from again becoming the wide enormous marsh or broad estuary. These early embankments of the Thames take us back to the latest stage in the history of the natural river, whose existence they may be said to have terminated. The magnitude and extent of these stupendous memorials of early civilisation in England is but little known or appreciated. Yet it is these which have converted the Thames into an aqueduct throughout the whole length of its tidal course. They extend from near Richmond to the mouth of the river. They stretch along the broad reaches and

It

The entire distance

follow the sinuosities of the river, winding up creeks and tributary streams, around islands, and about marshes. they thus traverse is not less than 300 miles.*

Thus vastly do these function and in the

old earthwork embankments surpass in their prowess of their unknown builders the ornamental river wall which is the newest boast of London to-day. Were there no embankment at Kew the Thames must fail to reach London as a river.

What the country below London would be without its river embankments may easily be seen at Dagenham. Dagenham is celebrated in the annals of the Thames engineers. It is here that the skill and persistence of man in conflict with nature have been tasked to the utmost in the endeavour to keep the river a captive. Here at Dagenham (on the north bank of the river, and a little to the south of the village), we may stand on an embankment which rises to a height of forty feet above the low-water level of the river, and prevents it from entirely changing its course. We might multiply instances to show how largely the Thames of to-day is the gift of civilisation rather than of Nature-the creature as well as the servant of man.

The Thames of the Mammoth Period.

But the old embankments of the Thames can take us no further in our upward route than the beginnings of civilisation in Britain. It is here, when we are almost in sight of the natural and primitive river, that we must cast ourselves adrift from the so-called historical period, and embark on the expanse of the wide geological ages. But the prospect, according to the geologist, need not dismay us. In comparing the chronicles of Nature with the chronicles of man, it is not seldom that terra firma is found outside and beyond the so-called historical periods rather than within it. In the history of rivers, seas, and continents, we arrive, as it were, at

*Lives of the Engineers, I., v.-"A good idea of the formidable character of the embankments extending along the Thames may be obtained by a visit to Dagenham. Here the banks are from seventeen to twenty five feet

high, and from twenty five to thirty feet at the base."-Ibid. Mr. Smiles gives two remarkable views of the river at high water at Dagenham, in which the character of the Thames as an aqueduct is well shown.

visible landmarks, signalising to us definite eras of geographical change, and indicating the processes and events which give sequence and history to phenomena.

Sir Charles Lyell, following an eminent geologist of the last generation,* refers us to an era in the history of the Thames when it was probably a tributary of the Rhine. "For England was then united to the Continent, and what is now the German Ocean was then land." Such was the current tradition in England even

before the spread of geological discovery.

The Gaul, 'tis said in antique story,

Saw Britain link'd to his now adverse strand,

No sea between, no cliff sublime and hoary,

He walked with unwet feet through all our land.

This former continuity of land which is now separated by the Straits of Dover, the existence of which would be an eventful phase in the history of the Thames, is credible upon evidence which is both stratigraphical and biological, and seems to make it certain, even to the ordinary observer, that the Thames has had its continental as well as its insular period of existence. The separation of England from the Continent is geologically recent. We still find on the shores of Kent the beds of old rivers which obviously were once continuous farther eastward, but which now end off suddenly at the top of the scarp, at a height far above the sea level.

The geographical conditions of primeval England which rendered it possible for the Thames to be a tributary of the Rhine are necessary in the eyes of the biologist to account for the presence in our land of huge, strange, and now extinct species of the brute creation, the remains of which are found to-day in the river-valley about London. These gigantic creatures, the mammoth and its fellowelephants of other species, the rhinoceros, the hippopotamus, and others, contribute a romantic yet sober chapter to the natural history of the Thames. Monstrous fleece-clad quadrupeds grazed and browsed on the banks of the Thames and drank its waters. The Siberian mammoth, with long black hair and an undercoat of reddish wool; elephants of other species, and two-horned

*Quarterly Geological Journal, vol. ix.

Antiquity of Man, chap. ix.

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