On Earthquakes in Devonshire (1884)
|Author(s):||Parfitt. Edward||Origin:||DA Transactions|
|Topic(s):||earthquakes and geology||Year published:||1884|
By Edward Parfitt. (Read at Newton Abbot, July, 1884.)
Parts of Devonshire have from time to time been shaken by earthquakes, and it occurred to me, soon after the last shaking we had, on June 25th, 1883, that it would be well to collect all the information I could on the subject, considering it quite within the province of this Association. Earthquakes from the very earliest times to the present have puzzled philosophers as to their cause, the results of which are abundantly present in various parts of the world. The great loss of life and destruction of property are too familiar to require to be particularised. From some cause unexplained there have been more shocks of earthquake recorded for the year 1883 than for many years past. On June 13th shocks were felt over the entire district of Bergen and Aalesund, but more severely in the well-known Dalsfjord. A further shock was felt over the same district on June 15th, at 1.30 p.m. On June 19th the island of Ometepee, in the Lake of Nicaragua, was devastated by an outbreak and eruption. On July 28th a shock of earthquake occurred at 7 o’clock on Sunday morning at Gurgitello. This shock was preceded, however, by an extraordinary increase in the temperature of the thermal waters at Casamicciola, but the inhabitants seem not to have taken warning that some outbreak was about to happen. On July 25th the Solfatara of Albano, one of the extinct Latin volcanoes on the southern side of the Roman Campagna, sent forth sounds such as never were heard before.* On August 16th shocks were felt in the Engadine, and though not of a severe character, still enough to shake or move beds, &c. Then, as a sort of finale, we had communicated to us the terrible catastrophe that occurred in Java, August 26th, 27th, 1883. In 1786 Java was greatly shaken by an earthquake which lasted four months; great clefts of the earth opened from which sulphurous vapours issued, in other places the earth sank and produced chasms, into one of which the river Dolon-Bach flowed, and in future followed a subterranean channel from that place. At this time the village of Djampang was swallowed up with all its inhabitants.
* See map and full particulars of this outbreak in Nature, September 6th, 1883, pp. 437-39.
The cause of earthquakes is still to be ascertained. The ancients regarded them as lightning shocks occurring in the earth, and we shall see that perhaps this is not so bad a comparison, when we consider how very local some are and how direct some of these local shocks have been traced. Colonel Parnell, in an article in the Journal of Science, ser. 3, vol. iv. pp. 697, vol. v., quite endorses this, and educes some very strong evidence in support of earthquake shocks being neither more nor less than electric discharges from the reservoirs of the earth. On the other hand, Mr. Howorth, in Nature, vol. x. 1874, believes that volcanoes are the immediate result of the shrinking of the earth. In 1852 Dr. Buist, of Bombay, in a letter to Prof. Baden Powell, says,
“It is now well established, that in India, at all events, earthquakes are always accompanied by furious storms of thunder, lightning, and rain. It is difficult to trace the cause of coincidences so remarkable in commotions of the earth and the air.”
Earthquake waves travel at different velocities through different rocks. From a number of experiments conducted by Mr. Mallet, he found that the velocity through sand was 825 feet per second, and through solid granite 1665 feet per second. Theoretically, however, this is not considered to be correct, as joints, &c, in rocks would interfere with the velocity.
In 1755, the Lisbon earthquake is computed to have travelled about 20 miles per minute, or 1760 feet per second. The shock at Naples was calculated by Mr. Mallet to have a mean velocity at the surface of 788 feet per second, whilst the greatest velocity of the wave-particles was never more than 15 feet per second. “But though seismic energy may thus become sensible at any point of the earth’s surface, there are, as everyone knows, certain regions particularly subject to earthquakes, and it is, in fact, possible to trace seismic bands of variable width following the great lines of elevation which divide the oceanic basins.” From Mr. Mallet’s discussion of his Catalogue of Earthquakes for three centuries, he was led to sketch definite periods of maximum seismic energy. Thus it is found that the “greatest number of earthquakes are recorded about the middle of each century, with a second epoch, less powerful than the first, occurring towards the close of each century.”*
* British Association Report, 1855.
And according to Perrey there is a preponderance of earthquake shocks at particular seasons; namely, at the equinoxes and solstices, which he terms critical periods. Mr. Mallet somewhat confirms this, and finds that the maximum occurs about the winter solstice. Mr. Richard Edmonds, jun., has, in a paper read at the meeting of the British Association, held at Cambridge, 1845, endeavoured to establish a connexion between the lunar phases, or the relative positions of the moon to the earth, and the periodicity of earthquakes. In this he seems to me to have failed completely. Like many other things, they sometimes agree, but in others fail. In this Mr. F. W. Rudler, the writer of the article in the Encyclopaedia Britannica (9th edition), partly agrees; but he says, “In the present state of our knowledge it would be rash to regard seismic force, whatever it may be, as a distinctly periodic force, or to insist upon any of those relations between earthquakes and meteorological phenomena which have sometimes been discussed.”
Baron Humboldt is of the opinion, from the various experiments instituted by him, having lived a great deal in countries where earthquakes very frequently occur, that no perceptible change can be discovered prior to, or at the time of, earthquake shocks, in the electrical condition of either the earth or its atmosphere. This distinguished traveller says, “During the violent earthquake of Cumana, on the 4th of November, 1799, I found the declination and the intensity of the magnetic force alike unchanged; but to my surprise the inclination of the needle was diminished about 48′.”* And he goes on to say that in all the violent outbursts of volcanoes the earth-tremors are limited to a small area round about them. It is, however, far otherwise with earthquakes; they sometimes extend to great distances. This, as will be seen, is in direct opposition to Dr. Buist, and others named, who support the electrical theory. Baron Humboldt, although he could not trace any direct atmospheric disturbance at the time of earthquake phenomena, admits that the magnetic needle was considerably disturbed.
* Cosmos, v. i. p. 203.
We do not appear to have gained anything in actual knowledge as to the cause of earthquake phenomena since the time when Humboldt penned these lines. He says,
“The intimate connexion of the phenomena which we have considered is still hidden in obscurity. Elastic fluids are doubtlessly the cause of the slight and perfectly harmless trembling of the earth’s surface, which has often continued for several days together. … The focus of this destructive agent, the seat of the moving force, lies far below the earth’s surface; but we know as little of the extent of this depth as we know of the chemical nature of these vapours that are so highly compressed.”*
* Cosmos, v. i. p. 210.
As observed by Mr. Rudler, it has been asserted that there are certain meteorological phenomena observable at or before the occurrence of earthquakes. I have heard the same stated myself; and to be on the safe side here, I wrote to the superintendent at the Physical Observatory at Kew, and on July 9th Mr. T. W. Baker, the assistant in charge, writes me: “I have looked over our magnetograph curves corresponding to the date you refer to, but I do not see any disturbance of an unusual character, in fact the traces only exhibit the ordinary daily range.”
In connexion with this Mr. E. Mallet, in British Association Report, 1850, p. 71, quoting Von Hoff, says,
“In many instances in which opportunity of observing the magnetic needle during an earthquake has presented itself, an alteration in its direction for the time has been observed. … More remarkable, however, are the changes in the direction of the dip and variation needles, which take place at a distance from the place where the earthquake was observed, and at a place where the shock itself is not perceptible. As, for instance, in Paris, on the 19th February and 31st May, 1822, simultaneously with an earthquake which occurred in Savoy and some of the north parts of France.”
Perhaps this shock was a more potent one, and extended further, than the one we experienced in this country, otherwise I do not see why the instruments at Kew should not have registered it.
On April 22nd, during the earthquake in Essex, the south current needles of the instruments at Greenwich Observatory showed a disturbance at 9.20 am.; but the horizontal magnets were not disturbed. At the Kew Observatory the magnetographs recorded the shock at 9h. 17min. 18secs., Greenwich mean time.
Whether earthquake phenomena are at all connected with the great physical disturbances on the surface of the sun has not been perhaps so thoroughly investigated as could be desired. Be this as it may, the year 1883 has been remarkable for both. The sun, as observed by M. Thollon, has been greatly disturbed. On July 22nd a long chain of spots was observed on the sun’s southern hemisphere, extending from limb to limb. The arrival of this group was heralded by the appearance of a prominence of extreme brilliancy at 4 o’clock on the 16th. This phenomenon consisted of a number of straight jets, apparently diverging from the same point of the limb. Continuing his observation on the 21st and 22nd of July, the southern half of the sun showed evident signs of violent agitation. Spectroscopically, all the metallic lines were more or less affected by this great disturbance of the sun’s disc.*
* Athenaeum, September 8th, p. 310, partim.
Notwithstanding that both Baron Humboldt and Mr. Rudler do not credit meteorology with having any connection with earthquakes, Dr. Gray, in his communication to the Royal Society on the earthquake on November 18th, 1795, says,
“The state of the atmosphere that accompanied this phenomenon is scarcely less remarkable than the earthquake itself. In the night of the 17th, it had blown with some violence from the south-west; in the morning the gale increased, and at eleven o’clock it blew a tempest, accompanied with very dark dense clouds, and with a greater degree of warmth, or rather sultriness, than I ever recollect to have felt in November, when there was no sunshine. About midday there fell a heavy rain for an hour, after which the wind abated, the clouds dispersed, and at six o’clock it was a serene calm evening. At the moment of the earthquake it was perfectly still, and continued so at one o’clock in the morning, with the same degree of warmth that had prevailed in the day. At eight o’clock the following morning it froze intensely, and the ground was covered with snow.”*
* Transactions of Royal Society, 1796, part i. pp. 370–71.
It is also recorded by the same gentleman, as he was informed, that
“at the time of the earthquake a remarkable light and coruscation proceeded from the south-west quarter of the heavens. The sudden change of temperature, from the warm air to that of the ground covered thick with snow, suggested the idea that the earthquake was intimately connected with the electrical phenomena of the atmosphere.”
In one of the numerous reports of the terrible earthquake at Krakatoa, the officers of the following ships report – that at 10 a.m. it was so dark aboard the steamship London, that not even the outlines of the ship or persons were visible; the needle of the compass was violently agitated, and the lightning struck the ship seven times; and the masts and yards were illumined by St. Elmo’s fire.
Those on board the ship Annersley say that at 10 a.m., August 27th, it was so dark that they had to light all the lights, and the barometer was rising and falling from half an inch to an inch in a minute. (Nature, January 10th, 1884.)
A similar description to the above was given by the master of the Charles Bal, which was about thirty miles from the island when the eruption broke out.
Notwithstanding then what has been said by Baron Humboldt and others, we have here direct evidence of atmospheric phenomena, especially that of St. Elmo’s fire, and the agitation both of the needle and of the barometric pressure.
A writer in the Times of Sept. 8th, 1883, p. 6, in which I think I trace the hand of Mr. Proctor(?) is comparing the structure of the moon with that of the earth, the moon being within easy telescopic distance, and having no atmosphere; or if it has, it is so extremely ratified that it forms no impediment to the investigator; we can therefore draw some analogy from the structure of the moon. The writer says,
“The moon is dead, it has not life enough left to ooze forth the tiniest mud volcano, or spurt out the feeblest geyser; no throb ever reaches its surface, and not the faintest rumble is ever echoed from its jagged mountain sides. No earthquake wave can ever sweep its island shores; for earthquakes there are things of the almost infinite past, and the last drop of water quitted the surface of the planet aeons ago. Its very atmosphere has deserted it; and if indeed there were ‘a man in the moon’ he could never hear the sound of his own voice…”
When the internal fires of our own earth have exhausted themselves, geologists say that we may look upon that as the beginning of the end. Not even the 600 degrees of heat of the sun, which beats upon every part of the moon for a fortnight at a time, is able to rouse within its bosom the faintest sign of life. We are told that our existing volcanoes and geysers and mud-holes are but the dying remains of what at the time must have been a volcanic activity, almost universal. Instead of spasmodic eruptions at a few isolated spots, we had a continual outpour of volcanic matters from wide fissures, extending across the earth’s surface for many miles. We have, as every geologist knows, plenty of evidence of this in the various eruptive rocks, which were very abundant in the early times of the earth’s history; and we have, as the writer in the Times observes, only a few outbursts now, as compared with those of former ages; but two especially have occurred – the one at Ischia, and the other at Java, which brought so much destruction upon these places, and have taught us that the earth’s fire is not yet extinguished.
The writer in the Times holds up a very dismal picture to our view in his comparison of the dead moon to our earth, and certainly if we are to draw an analogy from the condition of that satellite, our outlook is very far from a pleasant one. There is one consolation, however, to be drawn from this, and that is, we shall not be cognisant of it when that consummation arrives.
This writer goes on to say,
“When the blood leaves the cold extremities, and the heart has not vigour enough to send it to the surface, the end is not far off; and when volcanic and earthquake manifestations cease from the face of the earth, the end may be within almost measurable distance – much of its ocean waters will have been absorbed by the underlying rocks, and the atmosphere may be rarer and less life-giving than it is now. So long then as the mother of us all has any vigour left, we must expect her to manifest it occasionally as she has done recently at Ischia and Java.”
From this point of view we may earnestly pray that Vulcan will keep his fires burning, if these be the life-blood of the earth; and if occasionally he should cause some disaster, it is better that than to die out altogether.
The earliest earthquake shock I can find recorded for England, and from its severity it probably extended to this part of the country – but this is by no means certain – was in 1089,* August 11th, third hour of the night. This was felt throughout all England.
* Mallet, Brit. Assoc Rep., 1852, p. 22.
Frequently earthquakes and earth-tremblings are very local, and others again are of wide extent. Of one that occurred on April 6th, 1580, it is said that it extended throughout England, and in the district of London especially, where the great bells of Westminster were made to ring.
December 29th, 1661. – This was felt in England generally; it was a remarkable year for earthquakes throughout all Europe, and they lasted with slight intervals the entire year.
July 12th, 1748. – Between 10 and 11 p.m; direction S.E. to N.W.; shock felt at Taunton and English Channel to the Severn; this was also felt at Exeter and Crookhorne. – Phil. Trans. v. xlv. p. 398.
February 8th, 9th, 1749–50. – The Rev. Wm. Barlow writes to the President of the Royal Society on the shock of an earthquake felt at Plymouth: “Sir, it is proper to observe that the following relations are not made by mean, ignorant, or fanciful people, but by persons of good sense, whose veracity is unquestionable, and whose judgment in this case is, I think, rational and just. – William Barlow.”
The first witness to the above shock is a declaration of the Hon. Philip Vanbrugh, Commissioner of His Majesty’s Dockyard, near Plymouth; he was reading in bed, and was sensibly affected by a sudden shake.
We have also a declaration from Mrs. Vanbrugh, sister of the Commissioner, and of Mr. Slade, master shipwright of His Majesty’s Dockyard, and Mrs. Slade.
The year 1750 appears from the various reports to have been famous for earthquakes, even in England, as several are recorded; and one especially, which was very severely felt from London across the country northwards.
February 23rd, 1752. – Dartmoor and the neighbourhood was visited by an earthquake.
“A smart shock, which was felt in many places on the Moor, and in its immediate neighbourhood – Manaton, Moretonhampstead, and Widdicombe. In the last named village some houses were injured, and one of the pinnacles of the church was thrown down.” – Mrs. Bray’s description of this part of Devon, in Borders of the Tamar and Tavy, v. i. p. 310, ed. 1836.
July 15th. – A shock of rather a severe character was experienced in the Scilly Isles, at St. Mary’s. From this it seems to have travelled, but diminished in force, to Plymouth; it was felt at all the intermediate places in Cornwall. On the strand at Penzance unusual marks were observed in the sand at 10 o’clock a.m., where it was generally quite smooth. A space of 100 square yards was covered with little elevations like mole-hills, with holes in their tops, as if something had issued thence. From one of these depressions a jet of water of the size of a man’s wrist issued, a phenomenon never before observed or afterwards.
November 1st, 1755. – The great earthquake at Lisbon; the effects of which were felt by the agitation of the sea, the lakes, and the ponds of water. The sea rose at Dartmouth after nine o’clock above the highest tides, retaining this height for three-quarters of an hour. At Plymouth about 4 p.m. (the time of high-water) the sea retired, and then came back in eight minutes, in each case to the extent of six feet; the ebbing and flowing continued for some time. (Mallet, Brit. Assoc. 1852, p. 169.)
The Rev. Mr. Holdsworth, of Dartmouth, in a letter which was communicated to the Royal Society, and published in their Transactions, vol. xlix. part 2, 1756, p. 643; said it was observed by the pilots at the above place, that at
“9 o’clock a.m. there was a surprising agitation of the waters, and though there was but little wind, yet boats riding near the mouth of the river tumbled and tossed about as if they would leap into each other. During this fermentation [or boiling of the sea like a pot, as my informant expresses himself], though it was four hours’ ebb, the waters rose as high or higher than they usually do on the highest spring tides. This violent motion lasted about three-quarters of an hour.”
This agitation of the sea was observed at Plymouth, Mount’s Bay, Penzance, &c. In a letter of John Huxham, M.D, F.R.S., to Mr. William Watson, F.R.S., he says:
“On Saturday, November 1st, about 4 p.m., just about high-water, we had an extraordinary boar, as the sailors call it. The sea seemed disturbed about twenty minutes before, though there was very little wind that day or for some days before. … When I came home one of our surgeons, who had then just crossed the ferry at Oreston, a mile to the south-east of Plymouth, told me that the tide had made a very extraordinary out [or recess] almost immediately after high-water, about 4 p.m.; left both the passage-boats, with some horses and several persons, at once quite dry in the mud, though a minute or two before they had four or five feet of water. In less than eight minutes the tide returned with the utmost rapidity, and floated both the boats again, that they had near six feet of water. The sea sunk and swelled for near half an hour longer.”
This agitation of the sea was not confined to our own coasts, but was observed in Holland, Germany, Ireland, &c. At Portsmouth it occurred at 11 a.m., and Holland 11 a.m.; at Kinsale, &c, not till 3 or 4 p.m.
We have then a very long letter from the Rev. W. Borlase, A.M., F.R.S., to the Rev. Charles Lyttleton, LL.D., Dean of Exeter, on this same disturbance of the sea. He says that
“a little after two o’clock in the afternoon, the weather fine and calm, barometer at the highest, thermometer at fifty-four, the little wind there was being at north-east, about half an hour after ebb the sea was observed at the Mount Pier to advance suddenly from the eastward. It continued to swell and rise for the space of ten minutes; it then began to retire, running to the west and south-west with a rapidity equal to that of a mill-stream. … The sea then began to return, and in ten minutes it was, as before mentioned, extraordinary high; it ten minutes more it was sunk as before.”
There can be little doubt but this rising and falling of the sea, as above described, was the effect of submarine disturbance, probably at no great distance from our shores. At the same time we know, from the reports of the earthquake which occurred on the coast of South America, that the waves there rose to an enormous height, so as to carry ships up high and dry far inland. The waves caused by this earthquake were rolled across the seas to the shores of New Zealand.
February 27th, 1756. – The Rev. Mr. Prince, of Barnstaple, in a letter to the Rev. Jeremiah Milles, who read the letter to the Royal Society, writes:
“On Friday, the 27th February, at Ilfracombe, at six in the evening, the weather being extremely fair, as it had been for sometime before, the sea being exceedingly calm, a rumbling noise was heard like that which usually precedes what sailors call a ground sea, only it was much louder. The tide at the time was above half ebbed, and retired as far as the head of the quay, leaving the vessels within the pier on dry ground, when on a sudden the sea came on with a great run, filling the quay to the height of six feet perpendicular; and the water remained at the same height near half an hour, but all the time was agitated as in a storm.” (Ibid. p. 642.)
This was one of the most active years for earthquakes; no less than 104 are recorded by Mr. Mallet as occurring in different parts of the world.
July 15th, 1757. – Violent shocks of earthquake were felt at St. Mary’s in the Scilly Islands, and were strongly felt in both Cornwall and Devon. The shocks occurred at 6.15 p.m., and lasted from six seconds to half a minute. (Phil. Trans. v. i. p. 2.)
In some of the Cornish mines this earth-wave was very perceptible, and a noise like the roll of thunder or of heavy waggons in motion was heard, in the 18 to 70-fathom levels.
July 28th, 1761. – An extraordinary agitation of the sea was observed in Mount’s Bay, Fowey, and at Plymouth; but no land shock was experienced. (Mallett, Brit. Assoc. 1853, p. 142.)
August 19th, 1763. – A great disturbance of the sea occurred at Plymouth about noon – a sudden flux and reflux of the tide, similar to that caused by the great earthquake that occurred at Lisbon. At the same time a tremendous storm of thunder and lightning was raging overhead.
1774. – “On October 25th, about ten o’clock in the evening, a slight shock of an earthquake was felt in this city (Exeter). Its direction seemed from south to north. The tremulation of the earth lasted about two seconds, and greatly alarmed several families, particularly that of Colonel Newton, in James Street, where several doors were thrown open and the house-bells rung by the shock. It was also felt at the houses of John Short, Esq., and Mr. Gibbs, surgeon, near Palace Gate.” (Jenkin’s History of Exeter, edit 1806, p. 218.)
September 8th, 1775. – A shock of earthquake was felt at Barnstaple at 9.55 in the evening. This notice was kindly communicated by John Chanter, Esq.; extracted from a notebook of an ancestor of his.
May 3rd, 1809. – Barnstaple was alarmed by a shock of earthquake, which travelled from east to west, and lasted about one minute. It was accompanied with a rumbling sound.
May 31st, 1811. – “The sea rose on all the southern coasts, Cornwall as well as in Plymouth, from four to eight feet perpendicularly. Mr. Luke Howard states that at Plymouth it began at 3 a.m. and continued until 10; that at 6.45 the sea rose eleven feet.” (Edin. Phil. Trans. vol. xv. p. 618.) Mr. Howard records another disturbance of the sea a few days afterwards; namely, June 4th, at 4 o’clock, at Plymouth. This was also observed at Mount’s Bay.
October 20th, 1837. – Liskeard and the country round, as also in Devon. “This was accompanied by a sound like the rattling of a cart” (Royal Cornwall Gazette, November 3rd, 1837.)
October 27th. – Several shocks were experienced at Camelford and a dull noise heard. This, although so near, is not recorded for Devon. (Colla. Giorn. Astron. 1839, p. 112.)
November 24th. – It is thought that some confusion has arisen as to the date, and, as Mr. Mallett observes, the one above may really mean this one. (Brit. Assoc. Rep. 1854)
September 2nd, 1839. – Bristol, Newport, Cardiff, and all the West of England, were shaken by this rather severe shock.
July 5th, 1843. – An extraordinary oscillation of the sea at 11 a.m. was observed at Plymouth and Penzance.
October 30th, 1843. – A similar movement was recorded at both the above places by Mr. Edmonds in Report of British Association, 1845. The master of a vessel estimated the velocity of the wave as travelling at eight knots an hour.
May 23rd, 1847. – Another great agitation of the sea. It was noticed in Mount’s Bay at 5 a.m., but it seems to have reached its maximum at Plymouth between 8 and 9 p.m. (Edmonds’s Land’s End District, p. 82.)
April 2nd, 1858. – “A shock of an earthquake was felt at Plymouth and in Liskeard.” (Edmonds’s Land’s End District, p. 116.)
September 28th, 1858. – Mr. G. Wareing Ormerod says, in a paper published in the Proceedings of the Geological Society of London, 1858, p. 188:
“On the evening of Tuesday, the 28th September last, a slight shock of an earthquake was felt in the district adjoining the northerly edge of Dartmoor, and it appears to have been almost entirely confined to the vicinity of the junction of the granite and the Carboniferous rocks. No vibration of the ground was then felt; but a rumbling noise was heard, attributed at the time to a supposed explosion of the gunpowder mills on Dartmoor.”
At Druid (Ashburton), on the Devonian beds, near the edge of the granite, about a mile to the north-west of Ashburton, a rumbling noise like that caused by a carriage passing over gravel was heard.
At Moretonhampstead, (on the granite) about a mile and half from North Bovey, no motion was felt, but a sound resembling the roar of a furnace was heard. At a farm, on the granite, about half-way between Moretonhampstead and Chagford, the farmer heard a sound, and mistook it for the noise of a cart that was expected; he rose from his supper, lighted his lantern, and went out to meet it.
At Chagford, on the granite, both sound and motion were noticed, and Mr. Ormerod’s attention was withdrawn from writing by a low rumbling sound. This shock was also heard and felt at Tincombe and Drewsteignton. The sound was heard at the “Dartmoor Inn”. The shock appears, from the direction in which Mr. Ormerod traced it, to have made almost a circuit of the moor, and its line of action was the junction of the granite and the Devonian and Carboniferous rocks.
June 25th and 26th, 1859. – Very considerable oscillations of the sea occurred in Mount’s Bay, Falmouth, Fowey, and Plymouth. (Edmonds’s Land’s End District, p. 86.)
October 4th, 1859. – “An extraordinary oscillation of the sea was observed in Mount’s Bay. At St. Mary’s, Scilly, there was eleven feet of water on the tide gauge at 7 a.m. It then fell to nine feet without a stop. It began to rise, and in six minutes there were fourteen feet seven inches on the gauge. It made no stop, but kept ebbing and flowing. At Plymouth in the afternoon the agitation of the sea was very great.” (Ibid. pp. 88–91.) At Barnstaple bay and Appledore, pilots observed the tide to return seven times.
October 6th, 1863. – A rather severe shock of earthquake was felt, extending from London to Liverpool and the borders of Wales. A line drawn through from Liverpool, Derby, Wolverhampton, Birmingham, and Hereford, to Taunton and Exeter would seem to mark the course along which the shock travelled. The shock or shocks, for some experienced two, occurred as near as can be ascertained about 3.20 to 3.30 a.m. In several instances, the beds on which persons were sleeping rocked to such a degree that the sleepers were awakened; whilst others were aroused by the shaking and rattling of articles of furniture. In one case, a person who was leaning out of bed to reach something from a table was thrown upon the floor. The police on duty felt the shock very much.
At Exmouth, Budleigh Salterton, and Newton Abbot many of the inhabitants were awakened from their sleep. Mr. Hine of the “Feathers Inn”, Budleigh Salterton, heard a crash, and on going down found that two bottles of brandy had been dislodged from the shelf and broken. This shock was also felt at Axminster, Honiton, Sidmouth, Clyst Hydon, Southmolton, and Barnstaple, and at the Duchy Hotel, Princetown. (Devon Weekly Times, Oct. 9th, 1863, partim. p. 5.)
We have also a record of this earthquake, kindly furnished by Mr. Ormerod from his journal. The shock was distinctly felt by the servants of the rectory at Chagford; the doors and windows shaking, and a noise heard like papers being drawn along the floor. At the “Three Crowns Inn” there the inmates were so disturbed that they got up; and a Mr. Palmer heard a “rouse and rumbling like”. At Mr. Berry’s the servants asked in the morning for some wedges to fasten the windows, they shook so. At Sidbury Park, near Chepstow, the shock was felt by one of Mr. Ormerod’s sisters, at 3.30 a.m.
October 5th, 1866. – Mr. Ormerod felt a shock of earthquake at Chagford; it occurred at 8.55 p.m.
October 30th, 1868. – A shock of rather a severe character was experienced in Exeter and neighbourhood. At Rose Mount Villas, on the Polsloe-road, on a thick bed of Trias brick-earth, of which this ridge is chiefly composed, it was severely felt; also in York Buildings, Mount Radford, and in Dix’s Field. In York Buildings a house trembled so much as to alarm the household. The bells shook and rang. The lady of the house having lived many years in the West Indies recognised the tremor and peculiar sensation as that of an earthquake. At the Eye Infirmary, in Magdalene Street, Exeter, the inmates were much alarmed by the shaking of the building. At the Devon and Exeter Institution the writer of this heard an unaccountable noise, and his servant who had just gone to bed, at 10.30 p.m., said that it seemed to her as if the bed was being carried over to the other side of the room. As the bedstead was standing with the head N.N.E., the probability is that the earthquake wave travelled from east to west.
This same shock was felt at Chagford Rectory, but the time there stated was 10.40 p.m. There may have been some difference in the time kept by the clocks or watches between Exeter and this place. Mrs. Hames was in her bedroom with her maid-servant, and the governess said she felt the table shake. The Rev. H. Hames, who was in his drawing-room, said the shock passed from N. to S. (magnetic) with a crash.
August 29th, 1869. – A shock of earthquake was felt to the south-east of Exeter at 1 p.m., accompanied by a low rumbling sound. At 1.15 p.m. the same day a similar noise was heard, but no shock felt.
August 26th, 1871. – A shock was felt by Mr. G. W. Ormerod at his residence, Brookbank,Teignmouth, at 4.25 a.m.
April 14th, 1873. – A shock was felt along the south coast from Dawlish to Sidmouth, and the intermediate stations. It probably extended further, but I could not obtain the information to that effect. A gentleman residing on the high ground at Budleigh Salterton, described in a letter to me the shaking of the shutters of his house for the space of eight or ten seconds; and said had it continued longer he should have rushed out of the house. Many of the shopkeepers’ shutters rattled so much that they went out to see if someone was not trying to take them down.
A correspondent, “S. C.”, in the Western Times of the 18th, describes the shaking of the windows of the house at 17 1/2 minutes to 10 p.m. on Monday, April 14th. Other persons in the house heard the noise and came downstairs.
Another correspondent, in the Daily Western Times of April 19th, reports a peculiar ripple of the sea which was observed by several persons on Tuesday morning, the 15th. The ripple appeared to be about fifty yards in length and about the same in breadth, and about the same distance from the shore, opposite Maine Place. Some fishermen said they never saw such a peculiar motion of the sea before, and thought it was produced by the rising of a bank and the uncovering of rocks before covered by sand.
A friend residing at Kenton, who with his wife and family were sitting by the fire, describes a rumbling noise as if an iron bedstead had been drawn across the room overhead, the windows at the same time shaking. The master and his wife and servant at the Idiot Asylum, Starcross, were greatly alarmed, at 15 minutes to 10 p.m., by hearing a loud noise, so much so that they feared the whole building was coming down about them. This was in the old building facing the sea, and not the present Idiot Asylum, which has been built since.
The butler at Powderham Castle, the seat of the Earl of Devon, heard, as he described it, a noise like thunder, and went out into the garden to convince himself, but found a perfectly clear sky. A lady also in that neighbourhood, namely, at Mamhead, heard a noise resembling thunder at a quarter to ten. Another friend residing at Starcross described to me the noise he heard. Every window in his house rattled; there was no wind, it was perfectly calm, and he at once came to the conclusion that it was an earthquake. The time, on comparison, agreed with the others, namely, a quarter to ten p.m.
May 6th, 1883. – Mr. G. W. Ormerod very kindly extracted this from his Journal for me:
“At 5.55 Greenwich time a shock of earthquake occurred at Teignmouth; it was like the discharge of a gun. Felt at Dr. Lake’s in Bitton Street, near the Teign; the house stands on the New Red Sandstone. The noise was also heard by Johnson the waterman, and by Mr. Rudkin, L.K.Q.C.P., who was sitting in his chair; he went into the front room to see what had taken place. Mrs. Browne, at Westerland, in the New Road, felt a shake.”
June 25th, 1883, occurred the most noticeable earthquake that has happened for many years, and one which embraced a wider area than the generality of the shocks which occur in this district. The Rev. R. H. Manley, writing from Stokeclimsland Rectory, says,
“Unless I am greatly mistaken, we have just experienced two earthquake shocks in this parish. The first, which seemed to last about three seconds, occurred about 1.35 p.m.; and the second, which passed more quickly, about 2.10 p.m. The noise was like that of a heavy waggon rumbling along a hard and rough road. This house, a large and substantial one of stone, shook very perceptibly. Some members of my family were in the church when the first shock was felt, and report that the church was shaken, and the lamps hanging from the roof, from which in winter coronas are suspended, oscillated for some minutes.”
The correspondent of the Plymouth Mercury at Tavistock says,
“A slight shock of earthquake, which appeared to be travelling from north-west to south-east, was felt in the town of Tavistock yesterday afternoon at twenty-two minutes to two o’clock p.m. The shock caused great surprise to many of the inhabitants, and was more distinctly felt in some of the oldest houses. The inhabitants of Princetown and its vicinity about two o’clock in the afternoon were somewhat affrighted by two smart shocks of the earth, followed by a subterranean rumbling, which they compared to the passing of a very heavy waggon, or the echo of distant thunder.”
At Holsworthy the shock was felt at 1.36 p.m. Houses were shaken to their foundations, and furniture oscillated and rattled considerably. Much excitement was manifested, people rushing out of their houses, and making anxious enquiries as to the strange occurrence. The atmosphere at the time had a tendency to thunder. The shock was felt at Torrington; and at Okehampton it appears to have been severe. From this it seems to have extended eastward; and at Rochside, near Sticklepath, the seat of Mr. W. W. Symington, his men, who were at work under a long shed roofed in with sheets of galvanised iron, were startled by the noise made. At the Devon Great Consols Mine the men working in the 180 fathoms level were much startled by the quivering or shaking of the ground. It appeared to them that the various workings were falling together.
This earthquake was also felt at Bideford, Hartland, Clovelly, and Buckland Brewer. At Clovelly a gentleman who was writing was unable to proceed, through the vibration. The Bideford postman, who was standing near a cupboard in a house, was surprised all at once at the rattling of the china within.
Mr. Sherry, cabinetmaker, Exeter, who was on Dartmoor with a party of friends, says that he was in the valley near to Bratton Tor between 1.30 and 2 o’clock; his friends were on the top of the tor. Suddenly he heard a loud sound like the rumbling of heavy artillery travelling on a hard road. The sound approached him from the north, and appeared to pass away to the south, lasting, as near as he could judge, about twenty or thirty seconds. The trembling was comparatively slight in the valley; but on the summit of the tor, where his friends were standing on a large block of granite, the ground beneath their feet quaked to such a degree, and so alarmed them, that they fled as fast as they could run. For thirty-six hours before this occurred the weather had been very wild on the Moor; but at the time of the earthquake the clouds had cleared away, and the sun was shining brilliantly.
At Hatherleigh, at about 1.40, a gentleman was sitting quietly after dinner, when all at once a low rumbling sound was heard, accompanied by a tremulous motion, slightly heaving, the crockery rattling perceptibly. This lasted about three seconds.
It does not appear that this earthquake was so much felt on the south side of the county. At the same time it was felt at Sidmouth, Exeter, Teignmouth, Ashburton, and Plymouth.
A writer in the Western Morning News says of the direction of the shock or shocks, and the area covered by them:
“It would seem that, striking the southern coast of Cornwall, this travelled in a north-easterly direction, and affected a large area, extending at least from Lostwithiel on to the west to Ashburton on the east, and from the English to the Bristol Channel. The whole valley of the Tamar lay in their path, but the Three Towns seem to have been outside it.”
The chief places in Cornwall where the shocks were felt, so far as I am able to ascertain, are Padstow, Bude, Liskeard, and Lostwithiel.
On Tuesday, April 22nd, 1884, at 9.15 to 9.20 a.m., occurred the most severe shock of earthquake at Colchester and the whole district around, and reaching to various parts of London, Bury, Leicester, Bath, &c, and to the French coast at Boulogne. This proved to be the most destructive to property of any earthquake wave recorded in this country. Some described the shock as having a vertical motion, and others as both vertical and horizontal, with an undulatory motion. This latter is probably correct, and as such it was described to me by Dr. D. Kingdon. He informed me that a friend of his, a very sensitive lady, was lying down on a couch, and says that she experienced a peculiar sensation as of a movement of the earth. This was in the neighbourhood of the city of Exeter.
I have in this paper enumerated thirty-three earthquake disturbances, either of the sea or of the earth. There may have been more, but I cannot find that they have been recorded. According to M. Perry’s researches into seismic action, he comes to the conclusion that the shocks are more frequent at the time of the equinoxes than at other times, and especially at the summer solstice; but according to the researches of Mr. Mallet, after examining the evidence recorded of earthquakes from two thousand years before the Christian era down to the year 1850, the alternations of paroxysm and of repose appear to follow no absolute law deducible from these curves (referring to plates of curves in Report of British Association, 1858). He goes on to say that
“two marked periods of extreme paroxysm are observable in each century – one greater than the other – that of greatest number and intensity occurring about the middle of each century, the other towards the end of each. This is one of the most remarkable facts that these curves seem to point to. From about the fiftieth to the sixtieth year of each century both the number and intensity of earthquakes will be observed suddenly to shoot up. Again during the last quarter of the three complete centuries another, but less powerful, paroxysm is apparent.”
This would seem to contradict what Mr. Mallet had just advanced, that no law for these disturbances could be deduced from them. At the same time they appear to be governed by a law not yet defined. Again, M. Perry’s researches led him to the belief that seismic action was more active at the summer solstice than at any other period of the year. But this applies more to the northern hemisphere than to general distribution. In Mr. Mallet’s researches, which include the whole globe, he found that at the vernal equinox (March 10th to 30th) there were 310; summer solstice (June 11th, July 1st) 254; autumn solstice (September 13th, October 3rd) 249; and winter solstice (December 11th to 31st) 318. From this, the largest number of observations that has ever been collected together, it is found that it is at the vernal and winter equinoxes the greatest seismic energy is developed. In our own – and I fear very imperfect – catalogue of earthquakes in Devon the greatest number occurred in July (viz., 6) and in October (8). Mr. Mallet observes, after taking into consideration the researches of M. Perry and others, “We cannot put aside the possibility that the fact may have a cosmical origin.” But what that really is remains a problem yet to be solved.
It has been suggested that earthquake shocks traverse the crust of the earth along the junctions of the older rocks; but this is scarcely borne out by experience, and, so far as our own county is concerned, the Triassic rocks are made to vibrate with the shocks quite as much as those of earlier date. In early times, when seismic forces were more active than at present in the British Isles, advantage appears to have been taken of the junction of the older rocks, being perhaps the weakest part, as it is on these lines that we find the most and largest of the eruptive masses of Trappean rocks. Of these we have many very excellent examples in Devon, such as Beleston, Rougemont, Exeter, Pocombe, Brent Tor, &c, and other eruptive rocks; and not as the Greenstones, which appear to have followed no lines of junction, but have been intruded into cracks and fissures occupying a wide area round the granite rocks of Dartmoor.
Having thus collected all the information I can concerning earthquakes in Devon, from the earliest to the present time, that I have been able to find recorded, and from the observations and experience of friends, and also from my own notes, I will conclude this paper with a forcible paragraph from that great practical physicist and excellent observer – Baron Humboldt, who thus speaks of the trembling earth:
“We are accustomed from early childhood to draw a contrast between the mobility of water and the immobility of the soil on which we tread; and this feeling is confirmed by the evidence of our senses. When, therefore, we suddenly feel the ground move beneath us, a mysterious and natural force, with which we are previously unacquainted, is revealed to us as an active disturbance of stability. A moment destroys the illusion of a whole life; our deceptive faith in the repose of nature vanishes, and we feel transported, as it were, into a realm of unknown destructive forces. Every sound – the faintest motion in the air – arrests our attention, and we no longer trust the ground on which we stand. Animals – especially dogs and swine – participate in the same anxious disquietude; and even the crocodiles of the Orinoco, which are at other times as dumb as our little lizards, leave the trembling bed of the river and run with loud cries into the adjacent forests.”*
* Cosmos, v. i. p. 204.
This very graphic description, by one who had had perhaps more experience in his day than any other we could name, is fully borne out by those whose experiences have been far less, who, when reflecting on this globe of ours, feel that we are in reality living on an elastic ball; and that the pent-up forces of the interior will, from some cause yet unexplained, rend and tear the crust on which we tread, causing devastation and ruin to some of the most prolific and loveliest spots on the face of the planet.
As to the conflicting theories that have been promulgated on the extraordinary brilliant sunsets and sunrises which began in October last, and continued with more or less interruption and brilliancy to the middle of January of the present year, the majority of the theorists have attributed the phenomena to the outburst of the volcano at Krakatoa, having projected the volcanic dust into the higher regions of the atmosphere, on which the rays of the sun have acted, and reflected the various and wonderful colourings which have been seen all round the globe. What appears to confirm this theory is the observation made by Mr. Whimper, on his ascent of Chimborazo, during an eruption of Cotopaxi. He says,
“We saw a green sun, and such green as we have never either before or since seen in the heavens; we saw patches or smears of something like verdigris-green in the sky, and then they changed to equally extreme blood-reds, or to coarse brick dark reds, and they in an instant passed to the colour of tarnished copper or shining brass. Had we not known that the effects were due to the passage of ash, we might well have been filled with dread instead of amazement.”*
* Nature, December 27th, 1883, pp. 199-200.
Another circumstance which appears also to confirm the dust theory is the following:
“A remarkable shower of white sulphurous ash fell in Glen Grey, about twelve miles from Queenstown, in the Cape Colony, towards the close of November. It was composed of little balls of white matter, which glistened in the sun; the fall alarmed both natives and the white population.”*
* Times, January 8th, 1884, p. 2.
This would seem to be almost sufficient evidence to substantiate the fact that it was volcanic dust which contributed to the brilliant colouring so universally admired; at the same time it is remarkable that it should remain so long, and that the dust should not fall to the earth, but remain suspended in the higher regions of the atmosphere for so considerable a time. To counteract this we have a theory propounded by Mr. A. C. Ranyard, embodied in an article in the Contemporary Review, January, 1884, p. 149, by Mr. Proctor, who says,
“As to the actual cause to which both phenomena are to be ascribed (the green and blue sun), we must, I think, exculpate Krakatoa from all part or share in producing these strange effects. The appearance of a blue sun at Trinidad, followed two or three days later by a green sun in the East Indies, cannot possibly be associated with the occurrence of an earthquake on the Java shore a few days earlier. We seem obliged then to support a theory, first advanced, I believe, by Mr. A. C. Ranyard, that the phenomena were caused by a cloud of meteoric dust encountered by the earth, and received into the upper regions of the air, thence to penetrate slowly (mayhap not till many months have passed) to the surface of the earth.”*
* January, 1884, pp. 1, 2.
Mr. W. P. Marshall, in the Midland Naturalist, says, “It has been suggested that the erupted lava (at Krakatoa) was projected into the atmosphere in the form of minute hollow-glass vesicles, such as may be supposed to be produced by a sudden discharge of very high pressure steam through a layer of melted lava.” But several independent observers far in the interior of Australia, who knew nothing of the eruption that had taken place, nor had heard of the theories propounded, related, however, that showers of a peculiar dust had fallen all over the land of their own respective districts, confirming in this manner the theories that the colours were produced by dust; but whether meteoric or projected into the atmosphere by the volcanic outburst of Krakatoa has not been decided.
In a long and interesting article on “Les Rougeurs du Ciel”, by M. J. Jamin in the Revue des Deux Mondes, March 1st, 1884, pp. 161–182, reviewing the various letters which have appeared in the journals, M. Jamin at length adopts the views of the majority of writers, that these brilliantly coloured skies were due to the volcanic dust projected into space from Krakatoa.