HYPSOMETRIC ADDENDA. 



I AM indebted to Mr. Pentland (whose scientific labours 

 have thrown so much light on the geology and geography 

 of Bolivia) for the following determinations, which he com- 

 municated to me in a letter written from Paris, in October 

 1848, after the publication of his great map : 



Nevado of Sorata, or Long, from Height in 



Ancohuma. S. lat. Greenwich. English Feet. 



South Peak 15 51' 33" 68 33' 55" 21286 



North Peak 15 49' 18" 68 33' 52" 21043 



Illimani. 



South Peak 16 38' 52'' 67 49' 18" 21145 



Middle Peak ....16 38' 26" 67 49' 17" 21094 



North Peak 16 37' 50" 67 49' 39" 21060 



The heights (with the exception .of the unimportant dif- 

 ference of a few feet in the South Peak of Illimani) are the 

 same as those given in the map of the Lake of Titicaca. A 

 sketch of the last-named mountain (Iliimani), as it shews 

 itself in all its majesty from La Paz, has been given by Mr. 

 Pentland in the Journal of the Royal Geographical Society, 

 Vol. V. (1835), p. 77. This was five years after the publi- 

 cation of the first measurements in the Annuaire du Bureau 

 des Longitudes for 1830, p. 323, which results I myself 



