822 THE POPULAR SCIENCE MONTHLY. 



on the flanks of Izalco, a volcano which has had since its formation in 

 1770 an eruption about every twenty minutes and twenty-one consid- 

 erable ones, has never been destroyed, nor have Santa Anna, San Mi- 

 guel, and Masaya, on the slopes of the volcanoes of the same names, 

 w^hich have had respectively seven, ten, and six great eruptions. San 

 Salvador, which is built on the slopes of Quetzaltepec, has been wholly 

 destroyed fourteen times, the last time on the 19th of March, 1873. This 

 volcano may be regarded as extinct, for it has had only one eruption 

 since the conquest, that of the 30th of September, 1659, when the cin- 

 ders flew as far as Comayagua, the capital of Honduras, and the lavas 

 formed the immense " bad land " {cheyre) of Quetzaltepec and buried 

 the Indian city of Nejapa. The principal of the eight craters of Quet- 

 zaltepec (or San Salvador as it is otherwise called) is remarkable for 

 its perfect regularity and its size, six hundred metres in diameter and 

 depth. The bottom is occupied by an almost inaccessible lake. The 

 appearance of the volcano of Lake Ilopango, in 1879-'80, probably 

 saved San Salvador from a fifteenth destruction. Omoa and Jucuapa, 

 built on the slopes of the extinct volcanoes of the same names, were 

 destroyed on the 4th of August, 1856, and the 2d of October, 1878. 



In a work published by the Government of San Salvador on " Earth- 

 quakes and Volcanic Eruptions in Central America," in which I have 

 given a detailed history of the phenomena, I have been able to show, 

 from original documents, that the destruction of Guatemala, on the 

 night of the 10th and 11th of September, 1541, was due, not to an erup- 

 tion of mud from the extinct volcano of Agua, as some authors suppose, 

 but to the rupture under the weight of the water, assisted by an earth- 

 quake, of the walls of its crater, which had been filled by the extraor- 

 dinary rdins of the preceding days. The eruption of Pacaya, on the 

 18th of February, 1651, and the ruin of Guatemala, which it occa- 

 sioned, were accompanied by the spectacle of frightened wild animals 

 seeming to seek the protection of man, as they did also during the 

 eruption of Coseguina on the 20th of January, 1835. The year 1770 

 witnessed the rise of Izalco — " the Lighthouse of the Pacific" — a mag- 

 nificent volcano, whose eruptions have since followed one another un- 

 interruptedly about every quarter of an hour, with explosions that are 

 frequently heard for ten leagues around. The great eruption of Cose- 

 guina, on the 20th, 21st, 22d, and 23d of January, 1835, perhaps one of 

 the most formidable eruptions mentioned in history, the cinders from 

 which flew as far as to Vera Cruz, Havana, Caracas, and Bogota, was 

 heard over the same circle of seventeen hundred miles in diameter. 

 The well-proved coincidence that these eruptions began on the same 

 day with those of the Chilian volcanoes of Aconcagua and Corco- 

 vado, all three situated in the chain of the Andes, is too remarkable 

 not to attract attention. The environs of the active volcano of Mo- 

 motombo from the 1st to the 20th of April, 1850, witnessed the emer- 

 gence of the new volcano of Las Pilas, now extinct. 



