461 



which I made at the mission of Esmeralda, is hi 

 3° 10' of north latitude, and 68° 37' of longi- 



Great Cataracts and the mouth of the Apure, and as the 

 daily loss was extremely uniform (between San Fernando de 

 Atabapo and Maypures, at 24° and 29° of temperature, 

 28 5"$ between San Fernando de Atabapo, the Kio Negro, 

 the Cassiquiare, and Esmeralda, from 22° to 24° of tempera- 

 ture, 27* 9"), the central part of Esmeralda may be consi- 

 dered as sufficiently well determined. This may be relied on 

 with more confidence, as my chronometric longitudes of the 

 mterior rest on those of Cumana and Caraccas, two points of 

 the coast where I had observations of the satellites of Jupiter, 

 lunar distances, and an eclipse of the Sun. The positions of 

 the maps which appeared before the publication of my obser- 

 vations of the Oroonoko err by excess toward the east and 

 the south. D'Anville alone, by a happy tact, saw better 

 than those who have followed him. As geographers hereto- 

 fore differed much in the absolute longitudes, whith they as- 

 signed to the points of land- fall (at Barbadoes, the island of 

 Trinidad, or at Cumana), I have reduced in the following 

 table, the longitudes to the meridian of the Castle of Saint 

 Antonio at Cumana : 



Esmeralda. 



W. lat. 3° 11' long. 1° 53' from astronomical observ, 



w. 



1 



58 



2 19 D'Anville. 



E. 



3 



40 



0 15 La Cruz Olmedilla. 



E. 



3 



38 



0 18 Surville and Caulin. 



E. 



3 



28 



0 8 Faden. 



W. 



3 



38 



0 8 Buache. 



The Spanish maps constructed from the materials furnished 

 by the expedition of Solano, admit 3° 44 ; for the difference 

 of meridians between Esmeralda and San Fernando de Ataba- 

 po ; but it is only 2o 7\ These same maps place Esmeralda 



