The Netherworld of Mendip: Explorations in the great caverns of Somerset, Yorkshire, Derbyshire, and elsewhere

H. E. Balch, Ernest A. Baker

The Netherworld of Mendip

Explorations in the great caverns of Somerset, Yorkshire, Derbyshire, and elsewhere

EAN 8596547047452

DigiCat, 2022

Contact: [email protected]

Table of Contents

PREFACE

THE NETHERWORLD OF MENDIP

THE CHEDDAR GROUP OF CAVERNS

ANTIQUITY OF THE CAVES OF MENDIP

CAVE EXPLORING AS A SPORT

EXPLORING WOOKEY HOLE

STRENUOUS DAYS IN THE EASTWATER SWALLET

SWILDON'S HOLE

THE GREAT CAVERN AT CHEDDAR

FIVE CAVERNS AT CHEDDAR

THE BURRINGTON CAVERNS

THE CORAL CAVE AT COMPTON BISHOP

LAMB'S LAIR

A CAVE IN THE QUANTOCKS

CAVE EXPLORING AT ABERGELE

CAVE DISCOVERIES ON THE WELSH BORDER

THE EXPLORATION OF STUMP CROSS CAVERN

SWALLET-HUNTING IN DERBYSHIRE

GIANT'S HOLE AND MANIFOLD

EXPLORING NEW CAVES IN DERBYSHIRE

A VISIT TO MITCHELSTOWN CAVE

INDEX

PREFACE

Table of Contents

The

objects of this work are twofold: to describe the actual incidents of various interesting episodes in the modern sport of cave exploring, and to give an account of the scientific results of underground investigations in the Mendip region of Somerset. Speleology is the latest of the sporting sciences: like orology and Arctic exploration, it has two sides, sport and adventure being the lure to some, whilst others are chiefly attracted by the new light thrown by these researches on the geology, the hydrology, and the natural history of the subterranean regions explored. The chapters dealing with the scientific results are by H. E. Balch, who has been working on the geology of Mendip, more especially among the caves, for upwards of twenty years: the accounts of actual experiences, in which the sporting side is predominant, are by E. A. Baker, who described the recent exploration of the Derbyshire caves in his Moors, Crags, and Caves of the High Peak, 1903. No attempt is made to traverse the ground so perfectly covered by Professor Boyd Dawkins in his fascinating volume on Cave Hunting, and elsewhere, most of the work described here being supplementary to that done by him, and, largely, outside the scope of his aims. The authors are indebted to the kindness of the Editors of the Liverpool Courier and Daily Post, the Manchester Guardian, the Standard, the Yorkshire Post, the Irish Naturalist, and the Climbers' Club Journal for permission to use the substance of various articles which have appeared in their pages, and to M. Martel, Mr. C. Blee, and Messrs. Gough for permission to reproduce a number of excellent illustrations by them.

THE NETHERWORLD OF MENDIP

Table of Contents

THE CAVE DISTRICT OF THE MENDIPS

"A land

of caves, whose palaces of fantastic beauty still adorn the mysterious underworld where murmuring rivers first see the light. In these words an imaginative writer describes Somerset, which shares with Derbyshire and Yorkshire the title of a land of caverns. Across it the range of the Mendips, a region of Old Red Sandstone and Carboniferous Limestone, 1000 feet above tide-level, stretches in a huge, flat-topped rampart for nearly 30 miles, from the town of Frome to the sea. No piece of country in the kingdom offers so much to explore. An abundant harvest is there waiting to be reaped; for on every side are obvious indications of half-buried gateways to the dark and secret pathways to the netherworld, and everywhere upon the surface of the Mendip tableland lie the open pits and hollows which the local speech calls swallets," that is to say, swallow holes, some of them dry, some actively engulfing streams, but all testifying to untold ages of water action.

This Limestone district lies far from the busy hives of industry, remote and secluded in the very heart of lovely Somerset. Only on the darkest of nights, with the clouds low in the sky, can the glare of the lights of Bristol be seen reflected far to the northward. One main line of railway, the Great Western from Bristol to Exeter, passes near it, and even that does not intrude beyond the margin of this Caveland. The rendezvous for the cave explorers of the district is usually the quiet little city of Wells, lying calm and secluded under the southern slopes of Mendip, in close proximity to all the principal caverns. A mile to the south-east rises the bold and picturesque Dulcote Hill, a fragment of the most southerly anticline of Mountain Limestone in the kingdom. From this point, rolling northward in a great fivefold anticline, Old Red Sandstone, Lower Limestone Shales, and Mountain Limestone form the great mass of the worn-down stump of the once mighty Mendip range. The extent of the denudation which has taken place indicates that this range was originally at least 5000 feet high, yet now in but a few places is the height of 1000 feet attained, and this is reached only by the Old Red Sandstone ridges laid bare in the prolonged course of that denudation. The first of these high ridges rises boldly to the north of Wells, and a steep climb of 900 feet in two and a half miles brings us to the summit of Pen Hill, or Rookham, from which a grand southward view is to be obtained. Immediately below, the three cathedral towers pierce the blue mist hanging over the little city we have just left. Beyond, the peat moors of the Brue and the Axe stretch away to the Isle of Avalon, sacred as the birthplace of our Christian faith in England. Here below us is that

"Island valley of Avilion,

Where falls not hail, or rain, or any snow,

Nor ever wind blows loudly; but it lies

Deep meadow'd, happy, fair with orchard lawns,

And bowery hollows crowned with summer seas."

Here, where Arthur's bones are said to have been found, and where traditions associated with him abound, his memory is kept green in the names of many well-known spots; and yonder rises Cadbury Camp, looked upon by many as the Camelot of romance. On the low ridge which intervenes between the valleys of the Axe and the Brue lies Wedmore, where King Alfred gained in the Peace of Wedmore such temporary respite from his foes as allowed him to gather strength for the great operations that resulted at last in the conquest and unity of the whole kingdom. Yonder, too, are the marshes of the Parrett and the Tone, around which cluster tales familiar to every schoolchild. In the marshes between the Mendips and Glastonbury, exploration has unearthed a most interesting example of a swamp or lake village, with great store of antiquarian material, throwing a flood of light upon a period of which little was known. Beyond lies Sedgemoor, where in 1685 took place the last battle ever fought on English soil; and throughout this neighbourhood the infamous Jeffreys worked his will in the judicial slaughter of countless Somerset men.

In the far distance the sunshine glints on the waters of the Bristol Channel, where, 60 miles away, the bold promontory of the Foreland rises sheer from the sea; to the south, upon the farthest limits of our vision, Pilsdon and Lewsdon mark the descent of our southern counties to the English Channel; whilst, on a clear day, between them is seen the summit of Golden Cap, the base of which is washed by our southern sea. Surely here is as fair a scene as eye could wish to see.

Only a pleasant walk away, the great chasms of Ebbor and Cheddar have rent the rocks asunder, forming two of the loveliest ravines in the kingdom. Northward across the intervening syncline of Mountain Limestone, pitted with swallets marking the entrances to many an unknown subterranean labyrinth, are seen the Old Red Sandstone summits of North Hill, crowned with its seventeen Neolithic barrows, and of Blackdown beyond, from whose bare top is seen the broad estuary of the Severn spreading out across the view, giving a glimpse of the coast of South Wales in the far distance, its busy factories showing their pencil-like chimneys against the dark hills behind. In the Channel the little islands of Steepholm and Flatholm mark the line of the original continuation of the great Mendip range into South Wales. The limestone shores of the former rise sheer from the sea, forming an impregnable fortress. Here, far below the level of the salt water around, a supply of pure water is obtained from the Limestone, brought, doubtless, from the Limestone area of Mendip by way of some hidden fissure.

Hard by, at Clevedon, is the grave of that great friend of Tennyson, who sat here and listened to

"The moaning of the homeless sea,

The sound of streams that, swift or slow,

Draw down æonian hills, and sow

The dust of continents to be."

Very truly and accurately his words describe the action that is going on, by which the swallet streams are undermining and honeycombing these hills and bearing their component rocks away to the sea.

Standing on Pen Hill and looking northward, a great east and west depression is seen forming a broad low valley in the tableland of Mendip. Into this valley numerous springs and a liberal rainfall are for ever pouring their waters. Yet nowhere is there a surface channel which can carry this water away; and nowhere, save in the small hollows of the Old Red Sandstone and Shales, does water accumulate. The reason is not far to seek. The Carboniferous Limestone, evenly stratified everywhere, has been split by vertical joints into a series of gigantic cubes. Between them, the surface waters, laden with carbonic acid obtained from the atmosphere and from vegetation, have for ages made their way, enlarging them by both chemical and mechanical action, till they have become fissures capable of giving passage to an enormous quantity of water. So from one joint to another, from one bedding plane to another, the water percolates downwards until it meets with some impermeable rock beneath, or until it finds an outlet at the level of the Secondary rocks forming the valley below. Such impermeable beds are found in the Lower Limestone Shales, and the resulting outlets are well known in the great risings of St. Andrew's Well in the gardens of the Bishop's Palace at Wells, in the source of the Axe at Wookey Hole, in the Cheddar Water and other large springs, of all of which more hereafter.

MAP OF THE MENDIP DISTRICT OF SOMERSET, SHOWING SWALLETS, CAVES, AND OUTLETS.

(Click on map to see a larger version. Not available on all devices.)

Reference to the sketch map of the district will show that the majority of the more important swallets lie along the line of the great depression referred to. These comprise by no means all the swallets of Mendip, yet they are the chief ones. It is obvious that the whole of the mass of material represented by this great depression has been removed in suspension by way of these swallets; and one is compelled to ask, How long has this work been going on? What time is represented by so vast a work? On the threshold of the inquiry we are met by such an amount of evidence bearing upon it that the subject must be dealt with separately. For, upon the upturned edges of the Carboniferous Limestone rocks, which can have been brought down to their present plane of denudation only by long-continued water action, have been deposited, and still remain in situ, great masses of the basement beds of the Secondary rocks, lying in such a manner as to convince us that swallet action had prepared the denuded surfaces upon which they lie. And upon this hinges the whole question of the antiquity of the caverns of Mendip. But whilst the age of our caverns is a debatable matter, no one can question the accuracy of the theory of ravine formation from the collapse of cavern roofs, as evidenced by the instances supplied by Mendip.

Through crevices and cracks, here, there, and everywhere, the percolating waters find their way. Now some crevice is enlarged into a passage; now some weak point in the passage becomes a chamber; and on the water rushes, steadily joining forces and accumulating, until on the level of the lower land it finds an outlet, and rushes forth a considerable stream. In its headlong course the water again and again leaps down some great series of potholes, as down some giant stairway, forming many fine cascades, whose deafening roar goes on for ever where there is no ear to hear and where no footstep ever treads the rocky ways. Along the course of the larger streams huge chambers occur; for the ever-eddying water, bearing sand along in its course, eats out the sides of its channel, or, revolving stones in its bed, carves out the pothole by friction. Or some pendent mass of rock has its support undermined and comes crashing into the streamway, only to be broken up and carried away by the ceaseless energy of the stream, so ever enlarging the chambers upwards towards the light of day. But whilst this action is going on underground, a more potent factor is at work where the subterranean stream first sees the light. Here very soon the action of the water alone gives rise to a little cliff overhead. Now rain and frost, wind and tempest, loosen, bit by bit, the fragments of rock forming the face of the cliff, which fall away into the river, to be broken up and carried away. Little by little the face of the cliff recedes, along the line of the subterranean river, until the first underground chamber is reached. The undermined archway of rock is less able to withstand the agents of denudation, and the cliff front recedes apace. Such is the present stage at Wookey Hole, the chamber whence the river Axe issues being still in process of destruction. Thus the work goes on slowly, yet none the less surely, until along the whole course of the subterranean river the roof of the cavern is destroyed, perhaps effectually hiding the stream under huge blocks of Limestone, such as those of Ebbor Gorge, near Wells, or until the water finds another course for itself, as at Cheddar, to begin the whole story over again. Every stage is abundantly illustrated by our Mendip swallets and caves. The large swallets of Eastwater, three and a half miles from Wells, of Swildon's or Swithin's Hole, a half-mile nearer Priddy, and the more recent swallet of Stoke Lane, half-way between Wells and Frome, are excellent examples of streams engulfed on the summit of Mendip. The whole of the country surrounding the two first-named caverns is dotted with innumerable small pits and hollows. The great swallet of Hillgrove, three miles north of Wells, in the exploration of which we are at present engaged, in an endeavour to penetrate the labyrinth of ways to which it will undoubtedly afford access, is a fine example of an intermittent swallet. Here three ways, carved deeply through the stream-borne sands and clays of some uncertain epoch of geological history, converge in a deep glen, beautiful with its tropical wealth of ferns. In the bottom of the glen huge spurs of Limestone stand up boldly, dipping towards the Old Red Sandstone exposed to the south, and pointing to a great fault, along the line of which the Limestone water is bound to accumulate in a huge triangular reservoir, the outflow from which may account for the summer flow of the Axe when the majority of the swallets are dry. In winter the converging torrents here find ingress into the Limestone, but, though pits and hollows abound on every hand, no foot of man has ever yet trod the hidden ways beneath. At a depth of 10 feet we have reached the first open channel, only to have it blocked subsequently by a fall of the treacherous gravel through which we have been working.

Vast dry swallets are represented by a great depression which we call the Bishop's Lot Swallet, on the road from Wells to Priddy. Here a huge hollow in the ground, perfectly circular and 300 yards round, shows us the largest swallet in Mendip. Though the surrounding land slopes gently to the