155 



point of the coast (lat 7° 35', long. 61° 5' ?), the frontier of 

 Columbia stretches across the savannahs, in which some 

 little granitic rocks stand prominent, first S. W., and then 

 S. E., toward the confluence of the Rio Cuyuni with the 



east on the great map of South America published by Mr. 

 Arrowsmith. This geographer indicates with sufficient pre- 

 cision Puerto Espana, in the island of Trinidad (65° 50 ') ; 

 but he makes the difference of longitude betweeen Puerto 

 Espana and Punta Barima to be 1° 52 ; , while it is only 

 1° 317, as determined with great precision by the operations 

 of Churruca (See above, vol. v, p. 718, and Espinosa Me- 

 morias de los Navegantes Espanoles, Vol. i, N° 4, p. 80—82) . 

 The south-east bank of the mouth of the Oroonoko is in 

 8° 40' 35* latitude, and 62° 23' longitude. If we determine 

 the mouth of the Rio Essequebo by the difference of lon- 

 gitude from Cape Barima generally adopted (1° 22'— 1° 30'), 

 we shall find the Essequebo to be about 60° 53'. This is 

 nearly the position fixed on by Mr. Buache, iivhis map of 

 Guyana (1797), which indicates the longitude of Cape Ba- 

 rima (62° 28 / ) very well also. Several geographers, captain 

 Tuckey for instance (Maritime Geography, Vol. v, p. 733), 

 believes the middle of the mouth of the Essequebo to be in 

 C0° 32'— 60° 41' j and it is probable, that the mouth of 

 this river has been compared with the position of Surinam, 

 or that of Stabrock, the flourishing capital of Demerary. 

 The reckoning on this coast, however, where the current 

 sets strongly to the N. W., tends to diminish the differences 

 of longitude in sailing from Cayenne to Cape Barima, and 

 to the island of Trinidad. The longitude of the mouth of 

 the little river of Moroco, situate near that of Pomaroun, 

 and serving as the frontier between the English colony of 

 Guyana and the territory of Columbia, depends on the lon- 

 gitude of the Rio Essequebo, from which it is 45 7 distant, 

 according to Bolingbroke, toward the west, and from 30' to 



