370 



Atlantic, the Alleghany Mountains, the course of the Mis- 

 sissipi, the RockyjMountains, and the coasts of the South Sea 

 that divide the confederation into four natural sections. I 

 the general maps that have hitherto been traced, had no 

 other errors than those of absolute longitude, and in preserv- 

 ing the differences of relative longitude, they displaced equal- 

 ly with regard to Europe (for instance to the meridians of 

 Paris or Greenwich), the five great lines we have just 

 named, the area of the partial divisions would not be alter- 

 ed. In order to estimate the effects of these unequal dis- 

 placings, I have compared on every map used for the calcu- 

 lation of surfaces, the longitude of New York, Pittsburg, the 

 confluence of the Ohio and the Mississipi, and of Taos, a 

 village of New Mexico, situated, so to speak, on the prolonga- 

 tion of the Rocky Mountains, and the bay of Nootka. The 

 three first points are founded on the excellent observations of 

 M. Ferrer. New York is 8° 22' 34" east of Morro of the Ha- 

 vannah, and this point being 84° 42' 33* by my observations 

 of the satellites, and according to the occulations of M. Fer- 

 rer, 84° 42' 43" west of Paris, we may admit, for the abso- 

 lute longitude of New York, 76° 20' 9". (Conn, des temps, 

 1817, p. 320 and 339; and my Astr. Obs. Vol. 2, p. 108). 

 The well determined longitudes of Pittsburg (82° 18' 30"), 

 of Albany (76° 4' 45"), and of Lancaster (78° 39' 30") serve, 

 by the proximity of those three points to the mountains; 

 to contain within just limits the chain of the Alleghanies. 

 The line of the Mississipi is fixed by observations made at 

 the mouth of the Ohio (91° 22' 45"), and at New Orleans 

 (92° 26' 15"). The chain of the Rocky Mountains which 

 divides the country west of the Mississipi into two great 

 sections, is not yet so accurately determined as to its longi- 

 tude as the three preceding lines. I suppose Taos of New 

 Mexico at 106° 50 7 ; Lewis and Clarke place the central 

 cnam of the mountains in the parallel 45°, at 1 14° 46' j but 



