415 



hitherto, except in the new edition of that of 

 Mr. Arrowsmith, but twenty-five leagues far- 

 ther south, between San Felipe and the mouth 

 of the Rio Guape. The manuscript map of Mr. 

 Requena, of which I am in possession, proves, 

 that the Portugueze astronomers had been aware 

 of this fact from the year 1783, consequently 

 thirty-five years, before it began to be indicated 

 on our maps in Europe. 



It being an opinion anciently received in the 

 Capitania-General of Caraccas, that the able 

 engineer, Don Gabriel Clavero, had constructed 

 the fort of San Carlos del Rio Negro on the 

 equinoctial line itself ; and as the latitudes ob- 

 served near this line were, according to M. de 

 La Condamine*, in fault by an excess toward 



passes through the confluence of the Rio Uanpe ? That geo- 

 grapher has in fact marked it near a river, to which he gives 

 the strange name of the Rio Cachiquiari de Baupes ; but he 

 places the mouth of the real Cassiquiare in 1* 20' of south 

 latitude, consequently three degrees twenty-two minutes 

 too far to the south. Such must be the effects of this kind 

 of guess work, unsupported by any astronomical observation 

 for a hundred leagues round. 



* " I was assured," says M. de la Condamine, " on arriv- 

 ing at Para, that I was precisely under the line ; yet I found 

 the latitude one degree twenty-eight minutes south. This la- 

 titude of a place, where no observation had been made, is 

 found marked by Laet, but no subsequent geographer had 

 followed this indication (Voyage a VAmazone, p. 179.) Fa- 

 ther Samuel Fritz, furnished with a semicircle of wood, 



