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♦ KNOWLEDGE ♦ 



[Feb. 1, 1886. 



same direction as the clouds, and tliiis neutralises the 

 effects of their motion. The same phenomenon -was 

 observed during the Calabrian earthquake ; and nothing 

 serves to give us a stronger imjiression of the turbulence 

 of those internal heavings which make the dry land as 

 unstable as the billows of a swelling sea. Trees whose 

 roots continued firmly embedded in the soil were seen to 

 lash the ground with their branches. 



It will be evident that the seat of disturbance was 

 beneath the rocky ribs of the Apennines. The super- 

 incumbent soil was swayed with violence bj- the vibra- 

 ting mountain-slopes. But the chief mischief followed 

 when the vibration ceased. For then the soil to which 

 motion had been communicated began to slide over the 

 now stationary granite, and this sliding motion being 

 quickly checked by the irregularities of the rocky 

 substratum, there resulted a destructive shock to all 

 objects — houses, trees, or living creatures — upon the 

 shaken plains. One may illustrate the nature of the 

 shock as follows : — Suppose a small tiible-cloth to be 

 lying on a large table with raised edges, and that a 

 varie<^y of objects stand upon the cloth. Then, if the 

 table be shaken with a gradually increasing violence, 

 these objects may continue in safety, provided the 

 motion is so managed that there is no abrupt change 

 of direction, and no sudden increase or diminution of 

 velocity. If the motion of the table be .suddenly checked, 

 the cloth would not immediately lose its motion, but 

 would slide till it was stopped by the raised edge of the 

 table ; and objects on the cloth would move with it, 

 until its motion was checked, when they would receive 

 a shock more likely to be destructive than any which 

 had been communicated to them while the motion of the 

 table continued. And just as such a cloth would 

 "rumple up," as soon as the motion of one end was 

 checked, so the soil of the Calabrian plains was found to 

 be in some parts abnormally raised, in others as strangely 

 depressed. " In the town of Terranuova," says Sir 

 Charles Lyell, " some houses were seen uplifted above 

 the common level, and others adjoining sunk down into 

 the earth. In several streets the soil appeared thrust 

 up, and abutted again.st the walls of houses ; a large 

 circular tower of solid masonry, part of which withstood 

 the general destruction, was divided by a circular rent, 

 and one side was upraised, and the foundations heaved 

 oat of the ground." 



As might be expected, the soil did not continue 

 unbroken by the violent shocks to which it was sub- 

 jected. In the central parts of the disturbed region, the 

 earth opened so widely as to swallow up large houses. In 

 Cannamaria many buildings were "completely engulphed 

 in one chasm," insomuch that not a trace of them was 

 ever seen afterwards. So violently did these chasms 

 clo.se their yawning jaws, that afterwards, when excava- 

 tions were made for the recovery of valuables, the 

 ■workmen found the contents of houses crushed into a 

 compact mass with detached portions of masonry. In 

 some instances persons were engulphed by one shock and 

 thrown out again alive by the following one. 



The magnitude of some of the fissures which were 

 formed during this earthquake affords startling indi- 

 cations of the tremendous violence of the earth's internal 

 throes. Grimaldi observed in the territory of San 

 Fill a newly-formed ravine half-a-mile long and twenty- 

 five feet deep, and another of similar dimensions in 

 llosarno. In the district of Plaisano three enormous 

 fissures were formed : one a quarter-of-a-mile long, about 

 thirty feet in width, and 225 feet deep ; the second, 

 three-quarters-of-a mile long, loO feet broad, and 100 feet 



deep; s,nd the third, nearly a mile long, 105 feet broad, 

 and thirty feet deejj. 



If any evidence were required as to the true nature of 

 the disturbance, it would be found in the remarkable 

 motions of masses slightly attached to the surface-soil. 

 Paving-stones were flung into the air, and masses of loose 

 soil flung in showers over the surrounding objects. 



In this earthquake 40,000 persons are supposed to 

 have perished, and about 20,000 by the epidemics which 

 followed. Dolomieu gives a painful account of the 

 appearance of the Calabrian cities. " When I pas.sed 

 over to Calabria," he writes, " and first beheld Polistena, 

 the scene of horror almost deprived me of my faculties ; 

 my mind was filled with mingled horror and compassion ; 

 nothing had escaped ; all was levelled with the dust : not 

 a single house or piece of wall remained ; on all sides 

 were heaps of stone so destitute of form that they 

 affoi'ded no idea of there having ever been a town on this 

 spot. The stench of the dead bodies still ai'ose from the 

 ruins. I conversed with manj' persons who had been 

 buried for three, four, or even five daj'S ; I questioned 

 them respecting their sensations in so dreadful a sitaa- 

 tion, and they agreed that, of all the physical evils they 

 endured, thirst was the most intolerable ; and that their 

 mental agony was increased by the idea that they were 

 abandoned by their friends, who might have rendered 

 them assistance." 



The destruction of the Prince of Scilla and a great 

 number of his vassals, was one of the most remarkable 

 events attending this deplorable catastrophe. He had 

 per.suaded his servants to seek their fishing-boats for 

 safet}', and went with them to encotirage them. During 

 the night of Feb. o, while they were sleeping, an enor- 

 mous mass of earth was flung from Mount Jaci upon the 

 plain near which the boats were moored. Immediately 

 the sea rose more than twenty feet above the level of the 

 plain. Every boat was sunk or dashed upon the beach, 

 and hundreds of persons who had been sleeping on the 

 plain were swept out to sea. The Prince and 1,430 of 

 his servants perished. 



f:.\RTHQrAKE AT EIOBAMBA. 



One of the most remarkable earthquakes ever ex- 

 perienced was that which overthrew Riobamlia on Feb. 4, 

 1797. A district 120 miles long and 00 broad was shaken 

 by an undulatory motion which lasted for four minutes, 

 and a far wider district felt the effects of the disturbance. 

 Within the space first named, in which the movement 

 was more energetic, every town and village was levelled 

 to the ground ; and many places were buried under large 

 masses flung down from the surrounding mountains. 

 Among these was the flourishing town of Riobamba. 

 Preceded and accompanied by no warning noises what- 

 ever, the terrific concussion in a few moments effected 

 the complete desolation of the unhappy district. The 

 earthquake was a singular combination of perpendicular, 

 horizontal, and rotary vibrations. So violent was the 

 perpendicular, or as it may be termed the explosive 

 movement, that hundreds of the wretched inhabitants 

 were flung upon the hill La CuUa, several hundred feet 

 high, on the further side of the small river Lican. 

 Then came a-horizontal movement, so rapidly sircceeding 

 the other that in many instances the furniture of one 

 house was found beneath the ruins of another. In 

 some cases property was removed so far from its 

 original place, that disputes arose among the survivors 

 of the catastrophe, and the Audiencia, or Court of 

 Justice, was for some time occupied in adjusting these 

 difficulties. Not less remarkable were the effects of 



