between 12 and 1 A.M., in the Midland Counties, from Lincoln to Northampton, and from Warwick to Bury St. Edmund's. We need not pursue the record. The century which has passed since the great Lisbon earthquake has contributed the usual proportion of movements to England, but they are not materially different in any of their features from the examples already presented. The echoes are dying away of the last earthquake, a gentle movement compared to many others, but it was felt from the English Channel to the Mersey, and from Hereford to Leamington and Oxford. The Malvern Hill was about the centre of the area, as it has often been before. The chronicles of British earthquakes are doubtless incomplete, but they present the appearance of much authenticity, and may be safely used in reasoning. The first thing that strikes us, on considering the facts, is the almost generally insulated character of the disturbance. Some particular shocks are acknowledged to be derived from France, but the greater number are marked by purely local effects. The area is often narrowed to the northern, or the midland, or the south-western, or the south-eastern counties of England; occasionally it occurs only in the south of Scotland, or the north of Ireland, or the northern half of Wales. In England-Lincoln, Nottingham, Northampton, Oxford, Hereford, Worcester, Exeter, Salisbury, Canterbury, and other cities and towns are marked as centres of disturbance, not seldom the circle drawn round them is quite a small one, and sometimes only a few miles round a village like Aynhoe, in Northamptonshire, little known except for its chalybeate spring. Within these areas, small as they are, the motions are usually complicated, often upward and downward, as would be the case with shocks whose origin was beneath. In succession, however capriciously, every corner of our islands is visited; though from the northern mountains of old Caledonia, from the south-west of Ireland, South Wales, and Cornwall, the reports are few and scanty. In the central parts of England the number of earthquakes is greatest, and they appear on the whole to have a rather prevalent direction from N.N.E. to S.S.W., which is that of the escarpment of the oolite; a prominent line of strike, due to an ancient very extensive upheaval of the old sea-bed. Another thing is to be observed; there is one remarkable pause in the series of English earthquakes, not occurring where any noticeable imperfection of record would be expected-it is in the fifteenth century, which actually contributes only one earth-shock to the catalogue of 150 or so since the year 1000. This will appear by the following table, in which the numbers are arranged in centuries: General. Local Occurrence. Worcester, Derby. Nottingham, Lincoln, Shrewsbury, London, Durham, Kent, London, Bath, Wells, St. Albans, Chilterns. No place named. No place named. Ryegate, Herefordshire, York, Gloucester, Bristol, Ruthin Staffordshire, Oxford, Aylesbury, Abingdon, Burford, What makes the earthquake pause of the fifteenth century the more remarkable, and the record more trustworthy, is the comparative poverty of the centuries preceding and following. And it is not a little significant to find in M. Perrey's general table of European earthquakes, from A.D. 306 to A.D. 1843,* a similar though less conspicuous reduction of their number in the fifteenth century. In this same century it has been found that volcanic eruptions were less numerous in Europe than in the two centuries before and in all the subsequent period; and it is observed both in regard to Vesuvius and to Iceland, the two active volcanic systems nearest to England.† Great earthquakes, such as live in the annals of mankind, are numerous enough to mark with an ominous shade many tracts of the earth's surface. Among the earlier notices may be signalised the formation of the Ciminian Lake, on the site of a city, and the appearance of the Alban Lake. The terrible earthquake which laid Sparta in ruins, and rolled down huge masses of stone from Taygetus, happened B.C. 464. The Japanese Lake in Oomi, 72 miles long, and 12 wide, is reported to have been formed in one night; and the great volcano of Fusi-Yama to have been thrown up B.C. 285. While Flaminius strove in vain by the Lake of Trasimene (B.C. 217), an earthquake of great violence overthrew Italian cities, diverted the course of rivers, and caused hills to fall. In the same year North Africa lost one hundred towns. In Asia Minor, twelve or thirteen cities fell to the ground, A.D. 17; Pompeii and Herculaneum were *Mallet's Report on Earthquakes,' 1858. shattered, shattered, A.D. 63, and from this time the countries touching the Mediterranean have never been free from shocks. In A.D. 115 Antioch was the centre of a great commotion. The city was full of soldiers under Trajan; heavy thunders, excessive winds, and subterraneous noises were heard; the earth shook, the houses fell, the lamentations of people buried in the ruins passed unheard. The Emperor leaped from a window, while mountains were broken and thrown down, and rivers disappeared, and were replaced by others in new situations. In A.D. 365 the Mediterranean region was awfully disturbed, the sea rejected, and its finny population laid dry along with ships of burden; but the returning sea overwhelmed the shores, swept away houses and people, and lodged boats of magnitude two miles inland. The sixth century appears conspicuous by the number and magnitude of earthquakes, among which was that of Antioch, 20th May, A.D. 526, when it is reported that 250,000 persons perished. Egypt came in for a violent shock in 742, and with it part of Arabia; cities overthrown, their inhabitants buried, mountains divided, the sea agitated in a terrible manner. In 746, Jerusalem and Syria; in 823, Aix-la-Chapelle and part of Germany; in 860, Persia and Syria; in 867, Mecca and Antioch felt severe movements; during the last a part of the mountain Acraus (probably the front of the cliff) fell into the sea. In 893 an Indian earthquake is said to have caused the loss of 180,000 persons. Coming down to later times we find, in 1530, the sea lifted up four fathoms above its wonted height, on the coast of Cumana, a fort laid in ruins, the earth opening and ejecting dark noisome liquid. In 1556, China had its turn, and the provinces of Sanxi and Santon were involved in darkness and ruin, The earth threw out fire, the waters flowed and re-flowed ten times in twenty-four hours. The Calabrian earthquake, witnessed by Kircher in 1638, was very destructive, Santa Euphemia being ruined and transformed to a lake, under the eyes of the good father. In 1660, besides the burial of a mountain under a lake, which took its place, near Narbonne, a singular circumstance is narrated by Kircher: one of the hot (boiling') springs lost its heat, and was no longer of use. In 1667, Ragusa, Dalmatia, Albania, all the Adriatic, were frightfully injured. Ragusa was ruined; the springs of water were all drained in a moment; the sea retired four times. Whatever exaggeration may be thought to cling to these This event must be distinguished from the total destruction of these cities by the famous eruption of Vesuvius in A.D. 79. accounts accounts derived from so many countries, it cannot be doubted that they are copied from real phenomena which were much alike in China and Cumana, in Asia Minor and Italy, in Syria and India. Everywhere violent vibrations, downsliding of hills, stoppage of rivers, formation of morasses and lakes, inrushing of sea-waves: nowhere a record of elevated tracts of land. From the vast number of phenomena recorded within the last two hundred years, during which period a large part of the globe has been explored by enterprising travellers, we may select the physical incidents in a few great earthquakes which throw light on the measure of natural force employed, and the manner in which it is exerted. The Lisbon earthquake, as it may justly be called, extended its ravages over an area of 4000 miles in diameter. After a period of clear autumnal weather, a day of uncommon gloom closed the month of October, 1755; and the next day, calm, warm, and foggy, in the midst of universal stillness, at 9.35 A.M., the earth groaned, and shook itself quickly and shortly, and then violently, so as to fissure and upset the greatest part of the city, sink or swallow up a newly-built quay, and destroy 60,000 people. The sea-bed was temporarily raised and let fall; the bar was laid dry for a time, and then covered 50 feet deep by the violently returning sea. The whole work of destruction was ended in six minutes, during which several shocks occurred, but one was pre-eminent in force. This day, November 1st, was memorable everywhere in Portugal: the ground opening with flame or smoke; St. Ubes swallowed up by the sea-waves, while rocks fell from its promontory of jasper. All Spain except the north-eastern provinces suffered in the same way; all North Africa and Madeira, England, Ireland, Scotland, Sweden, the Alps, Italy, and France felt the shock in various ways; and the sea-wave rushed across the Atlantic to the West Indian Islands. On account of its very large range both under the land and under the sea, the records of this earthquake furnish good opportunities of ascertaining the velocity of vibrations in rock and waves in water. The calculation was first made by Mitchell in his paper, of date 1760, in the 'Philosophical Transactions.' The velocity of the earth-wave was computed to be about 21 geographical miles in a minute. The same subject has been again investigated by Mr. Milne Home, who finds on the average of the whole a velocity of 13.5 geographical miles in a minute. The Calabrian earthquakes-for there was a series of them, lasting at intervals from 1783 to 1786-are among the most important important in the history of these phenomena, on account of the full and authentic report of them prepared by Signor Vivenzio, the royal physician. On the 5th of February, after a calm hazy morning, in the southern extremity of Italy, at 12:45, violent subterranean noises were heard, soon followed by a succession of earthquakes, growing stronger and stronger to a maximum, and again declining to rest, the whole occupying two minutes of time. In that short space of time, an elliptical tract of country included within diameters of 30 and 40 miles was shaken to ruin; the attack was repeated on the 6th and 7th of February, and again on the 1st and 28th of March. In 1783, no less than 949 shocks were experienced in Calabria, and in 1784 as many as 151! Sir W. Hamilton reports that in a circle of 22 miles' radius round Oppido as a centre, towns, villages, and farms were destroyed, and the face of the country was altered. If a radius of 72 miles were taken, it would include the whole area which suffered sensibly; 192 towns and villages were destroyed, and 92 greatly injured. Above 35,000 persons died from the effects of this severe visitation. The surface of the ground was in places raised, in others sunk; rivers were diverted, springs rose in new situations, often muddy or fetid; fissures opened, inequalities of level were occasioned, especially on the western sides of the mountains. Not fewer than 215 lakes or morasses were occasioned by displacements of ground, blocking up of watercourses, and the like. Sir Charles Lyell has devoted to this earthquake one of the most interesting chapters of the 'Principles of Geology.' In particular he has collected and studied the examples of subsidence of particular tracts of ground and sea-coast, the formation of fissures in soft and hard rock, the occurrence of inequalities of level on two sides of such fissures, in two adjoining houses, in the substance of a split tower, and the like. Vorticose effects on incompact structures-reversals of small objects, upward leaps of others-are all considered with attention. The original notices of fissures are very noteworthy, for magnitude and accompanying circumstances. In one case, near Jerocarne in Calabria, radiating fissures ran in every direction 'like cracks on a pane of glass,' and many of them remained open. In other cases, about the centre of the area convulsed, 'houses were swallowed up by the yawning earth, which closed immediately over them:' farmhouses were engulphed, deep abysses opened, and lakes were formed on the broken ground. The fissures were measured, and found to be in some cases half, three-quarters, and a full mile long; 2 feet, 15 feet, and 105 feet broad; and 25 and 30 feet deep, in one case above 100 feet, and in another 225 feet deep. Gulfs, 300 feet and 750 feet square, were opened; a calcareous mountain, |