346 NOTES OF A NATURALIST. 



the rapid condensation of large masses of vapour, 

 such as occurs at each heavy fall of rain, may deter- 

 mine temporary currents in the air in directions 

 opposed to the general and ordinary march of the 

 winds. Irrespective, however, of any such local 

 causes, we must bear in mind the general tendency 

 of air currents towards motion of a circular or spiral 

 character. When we meet a breeze blowing in a 

 direction contrary to that which ordinary experience 

 leads us to expect, we must not forget the possi- 

 bility that it may be a portion of the ordinary 

 current which has formed an eddy. The main facts 

 of meteorology are now well established, but the local 

 deviations may give room for prolonged study. 



Although I knew that the delay at both places 

 would be short, I looked forward with much interest 

 to the prospect of landing at Bahia and Pernambuco. 

 The latter place especially is known to be the chief 

 mart for the natural productions of Equatorial 

 America. Skins of animals, birds living and dead, 

 gorgeous butterflies and shells, are easily procurable ; 

 and a mere visit to the fish and vegetable markets is 

 sure to make a visitor acquainted with objects of 

 interest. But my expectations were doomed to dis- 

 appointment. 



We reached Bahia on the morning of July 27. 

 The city stands on a point of land north of the 

 entrance to an extensive bay, called by the Portuguese 

 Bahia de Todos Santos, and the proper name of the 

 city is Sao Salvador ; but the concurrent practice of 

 foreigners has established the name now in general 

 use. The steamer lay in the roadstead nearly a mile 



