CHAPTER XIX. 



WINDS. 



The winds are so intimately interwoven with all that facilitates 

 the intercommunication of the nations of the earth, that the subject 

 must naturally claim the attention of every one, and although steam 

 has in a measure become a substitute for them, in navigation, yet 

 the winds must ever be the great motive power employed in com- 

 merce. 



A true knowledge of the theory of the winds, the causes which pro- 

 duce and affect them, must therefore be of paramount importance. 



The theory, which has hitherto been received to explain the circu- 

 lation of the atmosphere, I cannot persuade myself, is either satis- 

 factory in whole or in part. It will be my endeavor, in this chapter, 

 to exhibit what I believe to be the true causes which govern and 

 produce the effects of the winds, and which will be found more in 

 accordance with the facts that have been accumulated, resulting in a 

 theory, which, I feel satisfied is based upon the immutable laws of 

 nature. 



My own experience has fully confirmed it, in the voyage of circum- 

 navigation, whilst in command of the Expedition, and, I trust, may 

 afford all the facilities I anticipate to others, and be the means of 

 directing the navigator to the shortest and best routes on the most 

 distant voyages. 



In order to place the subject more fully before the reader, I will 

 briefly recite the versions of the present adopted Theory of the Winds, 

 viz. : "That currents of air owe their origin to any circumstance which 

 has a tendency to disturb the equilibrium of the atmosphere. 



" Heat is the chief cause of the atmospheric currents ; for, wherever 

 there are two adjoining regions unequally heated, there is produced 



