1890.] x.vrnuAi. j^ciknckw of riirL.VDKLPHiA. 293 



and from the valley of the Ohio in the north almost to the Amazon 

 valley in the south. 



On the oOth of January, 1811, near the Azores there rose from the 

 surface of the sea a sub-marine volcano, which by the 15th of June, 

 1812 had risen 320 feet above the sea level. 



About the beginning of the year 1812, the valley of the INIissis- 

 sippi was the seat of fretjuent earthquakes, which often rapidly suc- 

 ceeded one another, but more feeble and less frequent east of the 

 Alleghenies. 



" The shock felt at Caraccas," says Humboldt " in the month of 

 December, 1811 was the only one that preceded the horrible catas- 

 trophy of the 26th of March, 1812." The day on which the destruc- 

 tion of the city occurred was a remarkably hot one. " The air was 

 calm and the sky unclouded. It was Holy Thursday and a great 

 part of the population was assembled in the churches. Nothing 

 seemed to presage the calamities of the day. At seven minutes after 

 four in the afternoon, the first shock was felt ; it was sufficiently 

 powerful to make the bells of the churches toll ; it Jasted five or six 

 seconds during which time the ground was in a continual undula- 

 ting movement, and seemed to heave up like a boiling liquid. The 

 danger was thought to be past, when a tremendous subterraneous 

 noise was heard, and of longer continuance than that heard within 

 the tropics in the time of storms. This noise preceded a perpendic- 

 ular motion of three or four seconds, followed by an undulatory 

 movement, somewhat longer. The shocks were in different direc- 

 tions from north to south and east to west. Nothing could resist the 

 movement from beneath upward and undulations crossing each 

 other. The town of Caraccas was entirely overthrown. Between 

 nine and ten thousand inhabitants were buried under the ruins of 

 the houses and churches. The churches of La Trinidad and Alta 

 Gracia, which were more than one hundred and fifty feet high and 

 the naves of which were supported by pillars of twelve or fifteen 

 feet in diameter, left a mass of ruins scarcely five or six feet in ele- 

 vation. The whole of the earthquakes, that is to say the whole 

 of the movement of undulation and rising,, which occasioned the 

 horrible catastrophy of the 26th of March, 1812 was estimated at 

 fifty seconds, by others at one minute and twelve seconds." 



Seven large towns lying west of Caraccas and extending into the 

 Columbian Republic, were destroyed by the same earthquake, and 



