252 COSMOS. 



ELias Mount 43 (on the west coast of North America): 17,855 feet, 

 according to the measurements of Quadra and Galeano. 



The volcano of Tolima:** 18,143 feet, according to a trigonometrical 

 measurement by Humboldt. 



The volcano of Arequipa: 45 18,883 feet, according to a trigonome- 

 trical measurement by Dolley. 



navigation near the landing-place in Vera Cruz, was first measured 

 trigonometrically from the Encero by Ferrer, in 1796. The measure- 

 ment gave 17,879 feet. I attempted a similar operation in a small 

 plain near Xalapa. I found only 17,375 feet, but the angles of eleva- 

 tion were very small, and the base line difficult to level. See Humboldt, 

 Essai Politique sur la Nouv. Espagne, 2me e"d. t. i, 1825, p. 166 ; Atlas 

 du Mexique (Carte des fausses positions), pi. x, and Kleinere Schriften, 

 Bd. i, s. 468. 



43 Humboldt, Essai sur la Geographic des Plantes, 1807, p. 153. The 

 elevation is uncertain, perhaps more than ^th too high. 



44 I measured the truncated cone of the volcano of Tolima, situated at 

 the northern extremity of the Paramo de Quindiu, in the Valle del 

 Carvajal, near the little town of Ibague, in the year 1802. The moun- 

 tain is also seen at a great distance upon the plateau of Bogota*. At 

 this distance Caldas obtained a tolerably approximate result (18,430 

 feet) by a somewhat complicated combination in the year 1806 ; Sem,a- 

 nario de la Nueva Granada, nueva edition, aumentada por J. Acosta, 

 1849, p. 349. 



45 The absolute altitude of the volcano of Arequipa has been so 

 variously stated that it becomes difficult to distinguish between mere 

 estimates and actual measurements. Dr. Thaddaus Hanke, of Prague, 

 the distinguished botanist of Malaspina's voyage round the world, 

 ascended the volcano of Arequipa in the year 1796, and found at the 

 summit a cross which had been ereuted there 12 years before. By a 

 trigonometrical operation Hanke found the volcano to be 3180 toises 

 (20,235 feet) above the sea. Thih altitude, which is far too great, was 

 probably the result of an erroneous assumption of the elevation of the 

 town of Arequipa, in the vicinity of which the operation was performed. 

 Had Hanke been provided with a barometer, a botanist entirely unprac- 

 tised in trigonometrical measurements, would certainly not have resorted 

 to such means after ascending to the summit. The first who ascended 

 the volcano after Hanke was Samuel Curzou, from the United States 

 of North America (Boston Philosophical Journal, 1823, November, 

 p. 168). In the year 1830 Pentland estimated the altitude at 5600 

 metres (18,374 feet 1 ), and I have adopted this number (Annuaire du 

 Bureau des Longitudes, 1830, p. 325) for my Carte Hypsometrique de la 

 Cordillere des Andes, 1831. There is a satisfactory agreement (within 

 T yth) between this and the trigonometrical measurement of a French 

 naval officer, M. Dolley, for which I was indebted in 1826 to the kind 

 communication of Captain Alphonse de Moges in Paris. Dolley found 



