156 Mr Hamilton's Observations on recent Earthquakes 



destructive. The number of earthquakes felt at Tacna between 1826 and 

 183G was very great, more than luO smart shocks having been felt within 

 a few weeks subsequent to the great earthquake of 1831. That convul- 

 sion extended over an immense space on sea and land, it having been felt 

 both at a great distance on the ocean, and also at Potosi and Chuquisaca.* 



When in Potosi in 1827, 1 made inquiry on the subject of earthquakes, 

 and learned that, since the foundation of that city in 1545, they had been 

 quite unknown there. The earthquake of 1831 reduced the sea-port 

 town of Arica to a mass of rubbish, while Tacna, as on former similar oc- 

 casions, escaped. Arica has been totally destroyed by earthquakes five 

 or six times since it was first visited by the Spaniards 300 years ago : 

 but, before 1833, the people there supposed that Tacna could not be af- 

 fected in the same calamitous manner. A stranger, when first residing in 

 that region, is surprised by frequent and novel concerts ; the principal 

 performers being dogs and donkeys, of which animals there are hundreds 

 in and about Tacna. They howl most dismally whenever a slight earth- 

 quake occurs ; and so sensitive are these creatures in this matter, that 

 their announcement, and the tolling of the church-bell, is often the only 

 intimation of the shock given to those persons not experienced in such 

 accidents. 



We will not advert to all the reported ominous appearances which, it 

 ■was said, were seen or heard prior to the great convulsion ; only that the 

 people in a vessel from the United States declared that, on the evening 

 before the earthquake of 1833, when they were above 100 miles from the 

 coast of Peru, they saw a ball of fire in the air ; that it was as large as the 

 full moon, and that, after several minutes, it burst into pieces, and fell in 

 the sea. 



I will state what came under my observation. On Mondaj- the 16th 

 September, one hour after sunset, Tacna was shaken by a single explo- 

 sion. There was not any subterranean noise, either before or after this 

 single loud report, which, at the same instant, was accompanied by an 

 upward movement of the ground. The night was very dark, the atmo- 

 sphere being still and dense ; at that time, there was not a barometer in 

 Tacna. Next day was dull, and more lowering than usual ; the evening 

 was like the preceding, with a very thick atmosphere. The earthquake 

 began, without any previous noise or warning, at six o'clock morning, 

 18th September 1833. I had the first intimation of it from the violent 

 movement of a stout iron bedstead, and the shrieks of the people in the 

 adjoining houses. The movement of the earth was at first vertical, or up 

 and down, with oscillations, or lateral motion ; then the movement was 

 in undulations, like water when agitated into waves, but still accompa- 

 nied with lateral, oscillatory motion. The movement of the earth was 

 terrible, and the subterranean noise was horrific ; and these, combined 

 witli the falling of houses all around, the continued lamentation of the 



* Vide Edinburgh Philosophical Journal for 1834. 



