126 EARTHQUAKES. 



north. And it is worthy of remark, that the first continuously active volcano (Antuco) is on 

 the same parallel with, and within 120 miles of the former city. Thence, southward, Ketre- 

 degui, Llayma, Llogoll, Villa Eica, Osorno, &c., succeed in rapid succession, which, serving as 

 so many safety-valves to the great internal cauldron, probably diminish the number of earth- 

 quakes as we go south. North of Antuco the evidence of activity of any volcano, during the 

 last quarter of a century, except the new crater near Talca, formed in 1847, and the solfataras 

 eastward of Chilian, is by no means conclusive. Mr. Darwin says* that the volcanoes along 

 the whole length of the Cordilleras of Chile were in eruption, and so continued for some months, 

 subsequent to the earthquake of February, 1835 quoting Mr. Caldcleugh, Dr. Gillies, and Mr. 

 Byerbach as authorities, all of whom, except the last, had their knowledge second-hand. 

 Within six weeks of the earthquake, he crossed the Andes by two passes, and must have seen 

 Maypu, San Jose, Tupungato, and Aconcagua four of these so-called volcanoes ; and had he 

 witnessed smoke or flame from either, so important a fact would have found place in his most 

 instructive and charming narrative. Captain Fitzroy, K. N., writing at the same epoch, 

 explicitly remarks :f "As to the state of the neighboring volcanoes, so various and indistinct 

 were the accounts of their action after and before the earthquake, that as yet I have no means 

 of ascertaining the truth ;" and we have the evidence of Professor Domeyko,| that no active 

 volcano exists from Copiapo to beyond Santiago. Therefore, in the absence of further testi- 

 mony, I would suggest that the supposed volcanic flames or smoke during earthquakes, within 

 the period mentioned, may have been only electrical displays, not unusual over the Andes in 

 summer, and which were rather more brilliant than common on these occasions. Not only 

 do three persons in five believe them volcanic lights, but editors of journals, whom we expect to 

 comprehend something of natural phenomena, gravely publish paragraphs telling of the new 

 eruptions. This was the case at the December earthquake. 



The absence of such vents in the northern and central parts of the republic may explain the 

 greater frequency of tremors there, and those concussive or pulsatory movements and vibrations, 

 similar to successive fracturing of their rock strata immediately beneath. Belief that the crust 

 of the earth is but a shell, and the origin of disturbance quite near to the surface, seems almost 

 a necessary consequence, else the crust must be immeasurably broken by fissures, and the 

 activity of internal combustion enormous. To the geologist, the loss of a few hundreds or 

 thousands of lives, or the annihilation of man's choicest creations, are effects of internal com- 

 bustion, unimportant in comparison with a continent uplifted or depressed, even though these 

 mutations extend through more than the " three score years and ten" allotted to him. Numer- 

 ous instances of instantaneous elevation and subsidence of great magnitude which occurred 

 during earthquakes, might be quoted from the authors already referred to, as well as other 

 analogous changes, more gradual, though scarcely less evidently attributable to the same agent. 

 Indeed geologists acknowledge that nothing not even the wind that blows is more unstable 

 than the level of the earth's crust ; and such quotations would swell the chapter unnecessarily. 

 We need not go out of Chile for illustrations : the sinking of a part of old Penco in 1570, and 

 the upheaval of the island of Mocha and the adjacent coast in 1835, are examples of one class ; 

 the myriads of fresh-colored and unbroken marine shells that lie on the sands of Atacama hun- 

 dreds of feet above the sea, and the geology of the Andes themselves, many designate as exam- 

 ples of the other. And this brings me to the fact alluded to as possibly bearing on the question 

 of the elevation of the Andes ; and our astronomical instruments have served geology, a role cer- 

 tainly not contemplated at their construction. 



Santa Lucia, one of the isolated hills on the inclined basin of Santiago, is an oval porphyritic 

 mass, whose columnar strata, resembling basalt, lie at every inclination from the vertical, 

 toward the west, to horizontal. The side next the Andes slopes at an angle of about 45, and 

 is slightly covered with decomposed rock, on which there is scanty verdure during a few months, 



* Transactions Geological Society, Vol. V, second series, 

 t Journal Geog Society, Vol. VI. t Annales des Mines, Tom. IX. 



