474 



stream of the river Platte, a branch known by 

 the name of the Cotes Noires f separates to- 

 wards the north-east from the central chain. 

 The Rocky Mountains seem at first to lower 

 considerably in 46° and 48° ; and then rise to 

 48° and 49°, where their tops are 1200 to 1300 

 toises, and their ridge near 950 toises. Be- 

 tween the sources of the Missouri and the river 

 Lewis, one of the tributary streams of the Ore- 

 gon or Columbia, the Cordilleras form in wi- 

 dening, an elbow resembling the knot of Cuzco-f-. 

 There also, on the eastern declivity of the Rocky 

 Mountains, is the partition of water between 

 the Caribbean Sea and the Polar Sea. This 

 point corresponds with those which we have 

 noted above, in the Andes of South America, 

 on the counter-fort of Cochabamba, on the east, 

 lat. 19° 20' south ; and in the Alto de los Ro- 



linked by chronometric lines, and some observations of the 

 satellites of Jupiter, at the Mississipi - } but it must not be 

 forgotten, that the place of those peaks relatively to Taos 

 -and Santa Fe of New Mexico, is much more uncertain. 

 Lafora and Rivera differ 18' in the lat. of Santa Fe, and the 

 combinations from which 1 was able to deduce the difference 

 of the meridians of Santa Fe and Mexico, are far from being 

 satisfactory. (See my Fol. Essay, Vol. i, p. lxi.) I expect 

 with impatience the observations made on the west of the 

 peaks. 



* Black Hills, which are 260 toises high they stretch 

 towards the parallel of 46°. 



t See above, Vol. vi, p. 426, 



