TRUE VOLCANOES. 407 



respecting the relative heights between the capital of Mexico 

 and Sante Fe del Nuevo Mexico, I here insert the chief 

 elements of the barometrical leveJlings. which have been com- 

 pleted from 1803 to 1847. I take them in the direction 

 from north to south, so that the most northerly, placed at 

 the top of the list, may correspond more readily with the 

 bearings of our charts : 12 



12 In this survey of the elevations of the soil between Mexico and 

 Sante Fe del Nuevo Mexico, as well as in the similar, but more im- 

 perfect table which I have given in the Views of Nature, p. 208, the 

 letters Ws, Bt, and Ht, attached to the numerals, denote the names of 

 the observer. Thus, Ws stands for Dr. Wislizeuus, editor of the very 

 instructive and scientific Memoir of a Tour to Northern Mexico, con- 

 nected with Col. Doniphan's Expedition, in 1846 and 1847 (Washing- 

 ton, 1848), Bt the Chief Counsellor of Mines, Burkart, and Ht 

 for myself. At the time when I was occupied from March 1803 

 to February 1804 with the astronomical determinations of places 

 in the tropical part of New Spain, and ventured, from the materials I 

 could discover and examine, to design a map of that country, of which 

 my respected friend, Thomas Jefferson, then President of the United 

 States, during my residence in Washington, caused a copy to be made, 

 there existed as yet in the interior of the country on the road to 

 Santa Fe", no determinations of latitude north of Durango (lat. 24 25'). 

 According to the two manuscript journals of the engineers Rivera, 

 Laforaaad Mascard, of the years 1724 and 1765, discovered by me in 

 the archives of Mexico, and which contained directions of the com- 

 pass and computed partial distances, a careful calculation showed for 

 the important station of Santa Fe", according to Don Pedro de Rivera, 

 lat. 36 12' and long. 105 52' 30''. (See my Atlas Geogr. et Phys. du. 

 Me.nquc, Tab. 6, and Essai Pol. t. i, pp. 75 82). I took the precaution 

 in the analysis of my map, to note this result as a very uncertain one 

 seeing that in the valuations of the distances as well as in the direc- 

 tions of the compass, uncorrected for the magnetic variation, and 

 unaided by objects in treeless plains, destitute of human habitations, 

 over an extent of more than 1200 geographical miles, all the errors 

 cannot be compensated (t. i, pp. 127 131). It happens that the 

 result here given, as compared with the most recent astronomical 

 observations, turns out to be much more erroneous in the latitude 

 than in the longitude, being in the former about thirty-one and in 

 the latter scarcely twenty-three minutes. I was likewise fortunate 

 enough to determine, nearly correctly, the geographical position of the 

 Lake Timpanogos, now generally called the Great Salt Lake, while the 

 name of Timpanogos is now only applied to the river which falls into 

 the little Utah-lake, a fresh water lake. In che language of the Utah 

 Indians a river is called og-wahbe, and by contraction ogo alone ; tim- 

 pan means rock, so that Timpan-ogo signifies rock-river (Fremont, 

 Expl. Exped. 1845, p. 273). Buschmann explains the word timpa as 



