rence of the impression made upon the ear in different individuals. To some the noise seems like the hissing of steam escaping from a locomotive, to others it recalls the rushing of wind in a gale, or the roar and thunder of a waterfall, or the rumbling of a heavily-laden waggon, or the harsh grating sound produced by the emptying of stones out of a cart, or the sharper explosive report of cannons firing. No doubt these differences are not all merely personal, but probably in some measure indicate differences in the nature of the underground movements themselves. Other senses have also frequently been affected. A feeling of giddiness or sickness is not uncommon, such as to remind the percipients of being at sea. People in bed have felt first one end and then the other end of the bed lifted up and let down again. Others have had their chairs rock under them; while, where the shock has been more than usually violent, people have been actually thrown down from a sitting posture. Many accounts testify to the alarm expressed by animals, both before and during the earthquakes. Dogs, horses, and cattle show in their several characteristic ways the terror which evidently affects them. Birds, too, share in the general feeling of alarm, and cases are on record where they have been shaken off their perches.

But in Britain, as elsewhere, it is the effects of the subterranean disturbance upon buildings that have been most observed and described, and that enable us best to judge of the nature and intensity of the different earthquakes. When the shock is slight, houses are felt to vibrate, but the movement may not be more perceptible than such as would be produced by the lumbering of a heavy lorry along a roughly causewayed street. From such a minimum of effect a gradually increasing intensity may be traced. Hanging objects, such as lamps and pictures, are made to swing. Bells are set ringing; sometimes with a curious appropriateness it is the townbell, usually sounded in case of fires, that is rung by the earthquake to announce its passage. Furniture is shifted from its position, sometimes even tossed about. Plaster is dislodged from ceilings and walls. Slates or tiles on roofs are made to rattle or are jerked off to the ground. Houses are so strained and distorted that, though no apparent structural damage is done, the doors will no longer open or shut without the carpenter's assistance. Chimneys are twisted round or overturned. Walls are cracked or thrown down, sometimes killing persons below.

Churches and cathedrals, from their size and height, have more especially suffered. In the year 1185 an earthquake, which was felt all over England, but more especially in the eastern districts, threw down the cathedral of Lincoln and many other buildings. Sixtythree years afterwards (1248) a still severer shock passed over the western counties and Wales; the cathedral of Wells was much injured, part of its tower being thrown down; the cathedral of St. David's was partially destroyed, and bears witness to the calamity still; while many churches in Somerset were damaged.

Rivers and lakes being particularly sensitive to the disturbances that affect the surface of the earth, numerous instances are on record of their sympathetic movements at the time of earthquakes in this country. The deep Scottish lochs were repeatedly agitated during the eighteenth century. Besides their disturbance at the time of the passage of the earth-wave from the centre of the great Lisbon earthquake of 1755, they were at least thrice thrown into commotion during the next thirty years. In 1761, in connection with another violent earthquake in the Iberian peninsula, the waters of Loch Ness rose, moving about two feet above their previous level on the shore, and with such violence as to sweep away boats from their moorings. In 1782 the lonely Loch Rannoch, in the very heart of Scotland, was thrown into agitation. In 1784 Loch Tay, for six successive days, showed an unwonted throbbing of its waters.

During some of the more serious earthquakes alterations have also taken place in the surface of the ground. The older narratives give sensational accounts of huge yawning chasms that opened and closed again, engulfing whatever stood on the surfacecattle, men, houses, and even entire towns. Putting these stories aside as probably exaggerations and as possibly indicative rather of land-slips caused by the operation of subterranean water, we yet find examples in which there seems no reason to doubt that the ground has actually been rent open and chasms of varying breadth and length have been left in it. The production of such cracks depends in large measure upon the nature of the materials at the surface and immediately below it. Indeed the character of the rocks has probably modified the effects even of the comparatively slight earthquakes of Great Britain. This influence was perceptible at the time of the last considerable shock-that of 1884 in Essex. Houses that stood imme

diately upon clay or near the junction of geological formations suffered more than those on gravel or other loose materials.

From an early period the narratives of earthquakes have commonly included references to the state of the weather at the time, and by many writers these underground commotions have been tacitly assumed to be part of the meteorological phenomena of our globe. Many examples of this association of ideas may be found in the earthquake registers of this country. At one time we hear of great heat and oppressive sultriness having preceded an earthquake; at another time it is a hurricane of wind with thunder and lightning and deluges of rain. That there may be some relation between the pressure of the atmosphere and the liability of subterranean rocks in a condition of strain to yield to any such disturbance of equilibrium as would be caused by the atmospheric change that produces a great fall of the barometer is not at all unlikely. But there can be no doubt that in the great majority of cases the connection supposed to be traceable between earthquakes and peculiar states of the atmosphere is imaginary. In the singular earthquake district of Perthshire, every variety of atmospheric condition has had its concomitant underground disturbance, so that Deacon Reid, a former worthy of Comrie, might well say that according to his observation there was "aye some kind o' wather when earthquakes happened." In like manner, every season can boast of its subterranean disturbances in Britain, but there is a decided preponderance in the number of those which have fallen in the winter half of the year. The earth's crust in this region seems to undergo a maximum of agitation in November and another in March, and to reach its most stable condition in May.

A good many of the recorded earthquakes are said to have been felt over the greater part of the country. From the latter half of the tenth century to the close of the seventeenth, somewhere about thirty are recorded to have shaken all England. But in most cases, even where the damage has been heaviest, only certain districts have been affected, in which moreover it has usually been possible to fix on some limited area where the shock has been most severe, and which consequently may be supposed to lie somewhere about the centre of origin. A considerable number of earthquakes have been experienced in the West of England throughout the basin of the Irish Sea and

northwards along the western part of the Scottish Highlands. A smaller proportion has been felt in the eastern part of the country, and more especially in the southeastern counties from the Humber to the English Channel. I have referred to the rarity of recorded shocks in the West of Ireland, where from the analogy of other parts of the globe they might be expected to be more numerous than in the tracts lying farther from the rim of the Atlantic basin. While their comparative scarcity in Western Ireland is probably a fact, we must at the same time remember that this region is but thinly peopled, and that the houses are mostly mere loosely-built cabins, in which a shock that would produce considerable vibration in a house or church might not be felt at all.

Undoubtedly the most curious earthquake district of the British Island is that of Comrie, in Perthshire, to which allusion has just been made. It lies on the southern edge of the Highland mountains, which are marked off from the region of the Lowlands by a great line of fracture in the earth's crust, that runs across the island from sea to sea. Towards the close of last century the earliest recorded underground movements of that locality were observed. In the year 1839 the shocks began to be more frequent and violent, and they continued with such vigour that no fewer than two hundred and forty-seven were counted in the two years that followed 3rd of October, 1839. Since that time there has been comparative quiescence, though every now and then another tremor occurs to remind the inhabitants that the rocks below have by no means come to a final condition of equilibrium.

On my first visit to this district, never having had any personal experience of an earthquake, I lingered for awhile half hoping that by some lucky chance I might be favoured at last. It was the gloomy autumnal season when rumblings below ground might be expected. I remember listening long to the roar of the swollen streams and the sough of the wind down the glen; but the sounds were all those of the upper air. My disappointment, however, was changed into chagrin to find, on getting up next morning at Crieff, only some six miles off, that there had been an earthquake through the night. There can be little doubt that these frequent shocks in the Comrie valley arise from displacements of the rocks along the line of the ancient dislocation underneath.

kept pace, on the whole, with the depression, the sea never became abysmal. Its depth may not have greatly varied, but over its floor there came eventually to be accumulated a depth of sediment amounting to many thousands of feet.

While these events were transpiring over the area of the future Europe a long succession of submarine volcanic outbursts took place in the west, across the tract that now forms the basin of the Irish Sea. Thick sheets of lava and copious showers of ashes were poured forth, which spread out upon the floor of the sea, and probably in some cases built themselves up into volcanic islands. As one centre of eruption died out another would break forth from where are now the hills of Waterford and the headlands of Pembrokeshire northward to the borders of Scotland. But the volcanic energy at last expended itself. The volcanoes sank one by one into the sea, and over their submerged streams of lava and hardened sheets of ashes the seaborne sand and mud once more gathered. As the downward movement went on not only were the volcanoes obliterated, but their very sites were buried under thousands of feet of sediment.

Even if we greatly cut down the excessive demands of time made by geologists in explanation of the old revolutions of the globe, enough is left to baffle the imagination that tries to realise the vastness of the periods which these changes witnessed. It might have seemed to a human eye-had human eye been there to see-that the islands and volcanoes of this primeval era had been for ever entombed, buried under such a deep covering of far-spread sediment, hardening by degrees into sheets of solid rock, that no convulsion would ever be likely to raise them up again to the surface. Yet such an anticipation would have been strangely falsified. By a series of convulsions, the most gigantic that have ever befallen the west of Europe, the huge pile of accumulated detritus, consolidated into sandstone, shale, and other solid rocks, and reaching a depth of at least three or four miles, was crumpled and upheaved. The movements in the more westerly districts were directed from south-east to north-west. The sheets of rock were accordingly ridged up into folds, which ran in a general north-east and south-west direction. Such was the force employed, and such the pressure under which it acted, that hard crystalline rocks were crushed and drawn out, as lead may be rolled beneath a heavy roller, or squeezed under a hydraulic press

until it flows into all the crevices of a mould. The flinty quartz pebbles of the old submerged gravel beaches were flattened and welded on each other as if they had been made of dough. Huge masses of rock were sliced off and driven over each other for miles. The ruptures within the crust of the earth were so many and so enormous that if, as is probable, they were in numerous instances produced by sudden snaps after prolonged tension, they must have given rise to earthquakes of altogether inconceivable violence. It was long before a condition of quiet settled down once more upon these regions. During successive ages renewed disturbances, still following the lines of the previous foldings, ruptured the crust of the earth, and produced such dislocations as those of the Great Glen and of the Highland border. Along many of these lines of fracture the rocks are probably still in a state of strain, so that the shocks which from time to time excite curiosity, or, when more pronounced, awaken consternation in the Highlands, are actually the descendants and feeble representatives of those titanic throes which convulsed Western Europe in the early days of geological history.

Out of the mass of rock dislocated and upheaved by these ancient cataclysms, the present high grounds of Britain and Scandinavia have in the course of ages been gradually carved by the working of the elements at the surface. It is strange to find among these rocks relics of the primeval islands that were so long and so deeply buried out of sight. Strange, too, to learn that out of the lava and ashes of the long extinct volcanoes, after their entombment under thousands of feet of sediment, some of the most picturesque scenery of Wales and the Lake district have been sculptured--the cwms of Snowdon, the peaks of Cader Idris, and the scarps of Helvellyn. Many of the prominent uplands of the country are memorials of the same great period of disturbance, showing still in their direction from south-west to north-east the lines of the undulations into which the solid crust of the earth was thrown, such as the ridges of the south-east and north-east of Ireland, of Wales, of the Lake country, of the southern uplands of Scotland, and of the Scottish Highlands.

The other great period of convulsion to which I have alluded brings us to a comparatively late era in geological history—a time of warm and equable climate, when over the hills and plains of Central Europe there spread a vegetation akin to that of the Medi

terranean, or even of countries nearer the equator. Man had not yet appeared, but there was an abundant and varied develop ment of animal life, belonging for the most part to types that have long since passed away, but including a few, such as the rhinoceros and tapir, which still survive. So far as geological evidence goes, there had been a prolonged period of quiescence in the volcanic history of the British area. After continuing for a long succession of ages, volcanic action at last died out, the latest explosions occurring somewhere in the neighbourhood of Exeter. But eventually a new series of eruptions began, and gradually spread over the wide hollow that extends from Loch Neagh through the line of the Inner Hebrides to beyond the far headlands of Skye. As earthquakes are usual accompaniments of volcanic outbursts, we may well believe that they played their part in the phenomena of these north-western volcanoes. But there was a remarkable feature in the eruptions which distinguished them from all the other volcanic phenomena of Britain, and which shows that the earthquakes associated with them must have been of an altogether exceptionally severe kind. The crust of the earth was rent open by thousands of long straight fissures, sometimes extending for sixty miles or more. These dislocations took place over an area of many thousand square miles, stretching across what is now the north of England, the greater part of Scotland, the north of Ireland, and the northern half of the Irish Sea. Up these yawning rents molten lava rose from below, probably in many places reaching the surface and pouring forth there in vast floods. The terraced hills of Antrim, Skye, Mull, and the adjacent islands are memorials of these eruptions. The lava that solidified within the walls of the perpendicular fissures now forms what are known as dykes, which make not the least singular feature of the scenery in the wide districts through which they range. Most sojourners by the shore of the Firth of Clyde remember them as long walls of dark brown rock which, standing out prominently above the rich red sandstone of the shore, strike on the one hand boldly out to sea as reefs on which the heaviest tangles swing, and on the other run straight as walls up the cliffs, amid the hanging festoons of honeysuckle and wild briar.

It would be striking enough if the dykes were confined to the lower grounds. Their number, breadth, and persistence would

afford a sufficiently vivid conception of the gigantic operations that produced them. But our wonder increases greatly when we discover that they mount even over the crests of some of the higher hills. In the uplands of the south of Scotland they may be traced for many miles, pursuing their course across moor and fell with such undeviating persistence towards the north-west, that the wanderer who knows their trend, can with their aid pilot himself even through a mist. Still more astonishing is the way in which they traverse the mountains of the Highlands. For instance, they cross Loch Lomond and climb across the lofty crests on either side of that deep depression. The Cuchullin Hills of Skye have been cleft by them from bottom to top, a height of 3,000 feet. Through these solid mountainous masses they cut their way with the same sharpness and in the same direction as among the softer strata of the lower grounds.

After such convulsions, the earthquakes recorded within human experience in Great Britain seem puny indeed. It might be thought that the subterranean forces have expended their energy, and that only prolonged quiescence is now to be looked for. But such an anticipation would be founded on no reliable evidence. We are still so profoundly ignorant of the prime causes of earthquakes, that it is impossible to offer any well-grounded opinion as to the future character of underground movements in this, or, indeed, in any country. Where for centu ries only feeble shocks have been experienced, it may be expected, or at least hoped, that such will continue to be the case for centuries to come. But we cannot say that the conditions for a violent concussion do not exist beneath us, and may not at any moment make themselves evident. This possibility may be remote, but it must be allowed to be a possibility. It will not, however, even when adequately realised, affect men's happiness or influence their conduct. The survivors of a volcanic eruption plant their vines once more trustfully on the slopes of the slumbering and treacherous volcano, and those who have barely escaped from the destruction caused by an earthquake, seek to build their homes again where they stood before. The awfulness of the catastrophe may for a while paralyse their minds; but time, which heals the wounds inflicted on the fair face of nature, softens the memory of the calamity, and life once more becomes as gay and hopeful as ever, as sordid and selfish, as miserable and despairing.