EARTHQUAKES. 



noise whatever. The great noise (clgran ruido) 

 which was heard under the cities of Quito and 

 Ibarra, but not nearer the centre of the motion 

 in Tucunga and Hambato, occurred from eigh- 

 teen to twenty minutes after the proper catas- 

 trophe. In the celebrated earthquake of Lima 

 and Callao (28th Oct. 1746), the sound was first 

 heard liiie a subterraneous peal of tlwunder.in 

 Truxillo a quarter of an hour later, and with- 

 out any trembling of the ground. In like man- 

 ner, long after the earthquake of New Granada 

 (Nov. 16th, 1827), which has been described by 

 Boussingault, subterraneous detonations were 

 heard in the whole of the valley of Cauca, with 

 great regularity at intervals of thirty seconds. 

 The nature of the noises heard on such occa- 

 sions is very various : rolling, rattling, clank- 

 ing like chains, occasionally in the town of 

 Quito like thunder close at hand ; or it is clear 

 and ringing, as if masses of obsidian or other 

 vitrified matters were struck in caverns under- 

 ground. - As solid bodies are excellent conduc- 

 tors of sound, as sound, for example, is trans- 

 mitted with ten or twelve times the velocity in 

 burnt clay that it is in air, the subterraneous 

 noise, it may be easily imagined, will be apt to 

 be heard at great distances from the place 

 where it is occasioned. In Caraccas, in the 

 grassy plains of Calabozo, and on the banks of 

 the Rio Apure, which falls into the Orinoco, in 

 the whole of a region of 2300 square miles in 

 superficial extent, there was heard an extraor- 

 dinary thundering noise, without any shock of 

 an earthquake, on the 30th of April, 1812, at the 

 very time that the volcano of the Island of St. 

 Vincent, lying 158 geographical miles off, was 

 pouring an immense stream of lava from its 

 crater. This, in respect of distance, was as if 

 an eruption of Vesuvius were to be heard in the 

 north of France. In 1744, on the occasion of 

 the great eruption of Cotopaxi, subterraneous 

 cannonadings were heard at Honda on the Rio 

 Magdalena. The crater of Cotopaxi, however, 

 is not only 17,000 feet above the level of Hon- 

 da, but the two points are separated by the co- 

 lossal mountain masses of Quito, Paste, and 

 Popayan, as well as by valleys and precipices 

 innumerable, besides lying 109 geographical 

 miles apart. The sound was certainly trans- 

 mitted not through the air, but through the 

 earth from a great depth. In the violent earth- 

 quake of New Granada (February, 1835), sub- 

 terraneous thunder was heard at the same time 

 in Popayan, Bogota, Santa Martha, and Carac- 

 cas (in the latter for a period of seven hours 

 without any shock), in Haiti, Jamaica, and round 

 the lake of Nicaragua in Mexico. 



These sonorous phenomena, when they are 

 accompanied by no perceptible shocks, leave a 

 remarkably deep impression even v/ith those 

 who have long dwelt in districts subject to re- 

 peated earthquakes. All seem to expect with 

 alarm what is to follow the subterraneous rum- 

 bling. The most remarkable example of unin- 

 terrupted subterraneous noises, without any 

 trace of earthquake, and comparable with no- 

 thing else, was presented by the phenomenon 

 which was known in the high lands of Mexico 

 under the name of the subterraneous bellowings 

 and thunderings (bramidos y truenos suhtcrraneos) 

 of Guanaxuato(**^). This celebrated and flour- 

 ishing mining town lies far remote from any 



active volcano. The noise continued from mid- 

 night of the 9th of January, 1784, for more than 

 a month. I have been able to give a particular 

 account of it from the report of many witnesses, 

 and from the documents of the municipality 

 which I was permitted to use. It was (January 

 13 — 16th) ae if heavy thunder-clouds lay under 

 the feet of the inhabitants, in which slowly roll- 

 ing thunder alternated with sharper claps. The 

 sound drew off as it had come on with decreas- 

 ing loudness. It was confined to a limited 

 space ; at the distance of a few miles off, in a 

 district abounding in basalt, it was not heard 

 at all. Almost all the inhabitants fled the town 

 in alarm, although great piles of silver bars 

 were contained in it ; the more courageous be- 

 coming accustomed to the subterraneous noise, 

 by and by returned and disputed possession 

 with the bands of robbers who had seized on 

 the treasure. Neither on the surface of the 

 ground, nor in the workings at the distance of 

 1500 feet below it, was there the slightest 

 movement of the earth perceived. Over the 

 whole of the Mexican highlands no noise of the 

 same kind had ever been heard before, neither 

 has the alarming incident recurred. Thus do 

 chasms in the interior of the earth open and 

 close ; and the sonorous waves either reach us 

 or are interrupted in their progress. 



The influence of a volcanic mountain in ac- 

 tion, however terrific or picturesquely grand as 

 an object of sense, is still always limited to a 

 very narrow space. It is very different with 

 the shocks of earthquakes, which are scarcely 

 appreciable to the eye, but their undulations oc- 

 casionally extend simultaneously to the dis- 

 tance of thousands of miles. The great earth- 

 quake which desolated Lisbon on the 1st of 

 November, 1755, and whose influences have 

 been so admirably investigated by the great 

 philosopher Emanuel Kant, was felt among the 

 Alps, on the coast of Sweden, in the West In- 

 dian islands, Antigua, Barbadoes, and Martin- 

 ique, and on the great Canadian lakes, as well 

 as in the small inland lakes of the basaltic plains 

 of Thuringia and the northern flats of Germany. 

 Distant springs were interrupted in their course, 

 an incident in earthquakes to which Demetrius 

 the Galatian directed attention in ancient times. 

 The hot springs at Tepliz ran dry, and then re- 

 turned deeply tinged with a ferruginous ochre, 

 flooding every thing. At Cadiz the sea rose 

 sixty feet high ; in the lesser Antilles it became 

 of an inky black colour, and the tide, which 

 generally rises but about twenty-six or twenty- 

 eight inches, mounted twenty feet above its 

 usual level. It has been calculated that a ter- 

 ritory more than four times the superficial ex- 

 tent of Europe was shaken by the earthquake 

 of November 1st, 1755. There is, therefore, 

 no other outward manifestation offeree known 

 — the murderous inventions of our race inclu- 

 ded—through which, in the brief period of a 

 few seconds or minutes, a larger number of 

 human beings have been destroyed: in 1793, 

 sixty thousand perished in Sicily ; from thirty 

 to forty thousand fell victims in the catastrophe 

 of Riobamba of 1797, and perhaps five times as 

 many in Lesser Asia and Syria under Tiberius 

 and Justin the Elder, about the years 19 and 

 526 of the Christian era. 



There are instances among the Andes of 



