ROTCn. — THE ATMOSPHERE IN THE TROPICS. 



271 



of direction of the upper currents differ radically, however, in show- 

 ing no southerly component, although one balloon, launched west of 

 the Canaries, gave the same direction as that obtained near these 

 islands, meeting interlaced currents from the southeast and south- 

 west, above the northeast trade. From the distribution of pressure 

 on the earth's surface it would be supposed that the upper anti- 

 trade ought to be especially regular in the region between Cape 

 Verde and the Canaries ; but this idea is contrary to the belief of 

 Professor Hergesell that the upper southeast and southwest winds 

 observed near these islands, and long considered to furnish a demon- 

 stration of the return-trade, are due to local disturbing causes. To 

 settle this question, Messrs. Teisserenc de Bort and the author again 

 sent the "Otaria," during the wnnter of 1906, to the south and west of 

 the region which had been explored by them the preceding summer. 

 Since this paper was presented to the Academy, Messrs. Maurice and 

 Nilsson, constituting the scientific staff of the " Otaria," have com- 

 municated the results of their atmospheric soundings, made from the 

 vessel to the westward of the Canaries, and these results appear in 

 Table III. The longitudes are from Greenwich. 



TABLE III. 



Winds observed in February, 1900, above the Atlantic, Southwest of 



THE Canaries. 



Feb. 13 



" 14 



" 15 



16 



Lat. 28° N, Long. 18° W. ENE to 2850 ni., NW to 3680 m., SW to 

 the culminating point of the balloon, 5300 m. 



Lat. 27° N, Long. 18° W. ENE to 1800 m., SSE to 2100 m., N to 

 2250 m., SW to 2500 m., NW stratum 500 m. thick, then SW to 

 5100 m. 



Lat. 26° N, Long. 19° W. NE changing to N up to 1350 m., NW 

 to 2600 m., WSW and SW to 5100 m. 



Lat. 26° N, Long. 19° W. NE to 1300 m., NW and W to 3150 m., 



strong SW to 3300 m. 

 Cirrus clouds (4 observations) from S 50° W. 



Lat. 25° N, Long. 20° W. NE to 2-300 m., NW to .3000 m., SW to 

 3250 m., WNW changing to W up to 3950 m., SW to 4150 m. 



Alto-cumulus clouds from NE, cirrus (2 observations) from S 

 30° W. 



Cirrus clouds from S 45° W. 



