President's A ddress. 



115 



The vertical movement, similar to that of a mine, threw 

 the bodies of many of the inhabitants to a height of several 

 hundred feet on to the hill of La Cullca. By the rotatory 

 movement, walls were changed in their direction without 

 being overthrown ; straight and parallel rows of trees were 

 inflected ; and in fields having two sorts of cultivation, one 

 crop even took the place before occupied by the other ; this 

 last phenomenon showing either a movement of translation, 

 or a mutual penetration of different portions of the ground. 

 Baron Humboldt, to whom we are indebted for this interest- 

 ing narrative, states that when making a plan of the ruined 

 city of Biobamba, he was shown a place where the whole 

 furniture of one house had been found under the remains of 

 another ; the earth had evidently moved like a fluid in 

 streams, of which we must assume that the direction was 

 first downwards, then horizontal, and lastly again upwards. 

 Humboldt distinctly ascertained that this great earthquake 

 was unaccompanied by any noise ; the great subterranean 

 detonation which was heard at the cities of Quito and 

 Ibarra — but not at Tacunga and Hambato, which were 

 nearer the centre of movement — occurred eighteen or twenty 

 minutes after the catastrophe. It is but right to state that 

 Mr Mallet, in his Eeport to the British Association on Earth- 

 quake Phenomena, maintains that there is no direct evidence 

 from any observed facts for assuming any vorticose motion 

 of the shock of an earthquake, or any other than a rectilinear 

 one. According to Mallet, Humboldt has fallen into the 

 greater error of mistaking the secondary effects of landslips, 

 and their twistings of the land, for those of vorticose motion. 

 —Rep. Brit. Assoc., 1850. Mallet ascribes the immediate 

 impulses producing earth-waves of shock to — 



1st, The sudden formation of steam from water previously 

 in a state of repulsion from the heating surfaces (known as 

 the spheroidal state), and which may or may not be again 

 suddenly condensed under pressure of sea-water ; 



2d, To the evolution of steam through fissures, and its 

 irregular and per saltum condensation under pressure of 

 sea- water ; 



3d, To great fractures and dislocations in the rocky crust. 



VOL. III. Q 



