OF BARON HUMBOLDT. 113 



ful city of Mexico. In January, 1804, Hum- 

 boldt undertook a greater excursion in order 

 to examine the eastern Cordillera of Mexico. 

 The heights of the volcanoes Popocatepetl and 

 Iztacchiuatl he measured trigonometrically ; 

 he also ascended the pyramid of Cholula, in 

 consequence of the beautiful view it affords of 

 the snow-covered summits of the surrounding 

 mountains and the valleys of Tlascala. 



Having finished these observations, the tra- 

 vellers visited Perote and Xalapa, where they 

 passed through almost impenetrable forests of 

 oak and pine. Humboldt succeeded, never- 

 theless, in measuring this district three times 

 with the barometer ; and in consequence of the 

 results of these observations, a high road was 

 made through these regions. His prolonged 

 sojourn in this part, and the results of his 

 numerous and varied observations, rendered 

 valuable service to science. After other inter- 

 esting investigations, Humboldt and his friend 

 Bonpland arrived at Yera-Cruz, on the Gulf of 

 Mexico, where they took passage on board a 

 Spanish frigate for Havana, in order to take 

 possession of the valuable collection which they 

 had left there in the year 1800. Two months 

 afterwards they departed for the United States 

 of America, and, after a violent storm on their 



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