253 



constantly in the shade, reckoning only the 

 observations made at periods when it did not 

 rain, between eighty-four and ninety-two de- 

 grees. The humidity had consequently much 

 augmented beyond the Great Cataracts, and in 

 the middle of a continent shaded by forests, and 

 watered by equatorial rains, it was almost as 

 great as on the ocean*. 



From the 30th of April to the 11th of May, I 

 had not been able to see any star in the meri- 

 dian, to determine the latitude of places. I 

 watched whole nights in order to make use of the 

 method of double altitudes ; but all my efforts 

 were useless. The fogs of the north of Europe 

 are not more constant than those of the equato- 

 rial regions of Guyana. On the 4th of May, I 

 saw the sun for some minutes ; and found by 

 the chronometer and the horary angles the 

 longitude of Javita to be 70° 22', or 1° 15' far- 

 ther west than the longitude of the junction of 

 the Apure with the Oroonoko. This result is 

 interesting for laying down on our maps the 

 unknown country lying between the Xie and 

 the sources of the Issana, placed on the same 

 meridian with the mission of Javita. The dip 

 of the magnetic needle at this mission was 26*4° 

 (cent, div.) ; it had consequently diminished 



* See above, vol. ii, p. 90 - y and p. 85 of the present vo- 

 lume. 



