473 



lute height. Towards 40° of latitude, on the 

 south of the sources of Padouca, a tributary 



published in the United States). Spanish Peak is succeeded 

 towards the north, by James Peak (38° 38 7 lat. 107° 52' 

 long.) between the sources of the Arkansas and the Padouca, 

 n tributary of the River Platte (Ne-brasca) , that is, shallow 

 water, in the language of the Otoes Indians, and not as 

 marked on a new French map, Rio de la Plata, riviere oV ar- 

 gent !) Finally, in lat. 40° 3', long. 108° 30', between the 

 two branches of the River PJatte, rises the Bighorn, or 

 Highest Peak, of Captain Pike, perhaps the Sierra Almagre 

 of the inhabitants of New Mexico. The central mountain 

 of these three great masses, James Peak, is estimated at 

 11,500 English feet (1798 toises) of absolute height j but 

 this height trigonometrically measured, is only 8507 English 

 feet (1330 toises) : the height of the base above the level of 

 the sea (468 toises) is not founded on a barometric measure- 

 ment, but on the estimates, somewhat vague, of the descent 

 of the three rivers Platte, Missouri, and Mississipi (Long^ 

 Exped. Vol. ii, p. 32, 382. Ap. p. xxxviii). Captain Pike, from 

 analogous hypotheses, but which are certainly not so good 

 as those of Major Long and Mr. James, assigned 1260 toises 

 of elevation to this table-land, or these plains at the back of 

 the Rocky Mountains. Mr. James computes in two cuts, 

 the loftiest summits of the Rocky Mountains to be, in 35o 

 latitude, 10,500 English feet (1642 toises) ; and in 41°, 

 nearly 12,000 English feet (1876 toises). The lower limit 

 of the perpetual snows appeared to him in 38|° latitude, to 

 be 1530 toises, a height which, in the system of European 

 climates, corresponds to 40° of latitude. The astronomical 

 positions assigned by Major Long, to the eastern declivity of 

 the Rocky Mountains (107° 20' west of Paris, in 38° of lati- 

 tude) appear to merit great confidence, the Peaks being 



