184 Voyage of the Novara. 



laid down, that they hold good in minor cases, and must 

 remain of the same efficacy, whether it be a hurricane or a 

 dust-whirl which may be under consideration. 



So, too, in conformity with those laws, light winds may 

 be found subject to a variation in direction of a similar nature, 

 such as may not perhaps be fully exemplified in every case, 

 but simply serve to indicate the tendency of the wind to follow 

 the same general direction as the hurricanes themselves. 



The importance of ascertaining such curvilinearity in the 

 direction of the winds will be especially manifest at the limits 

 within which the regular winds prevail, and when they must 

 necessarily become intermingled with other regular currents 

 of the atmosphere. 



Accordingly, as we neared the limit of the S.E. Trades, which 

 always extend somewhat further south, as the sun's southern 

 declination increases, we had to traverse regions where 

 necessarily we encountered variable winds, owing to the in- 

 creased area of the Trades. There are also found occasional 

 spots at which a more rarefied atmosphere seems to fill the 

 surrounding space, when there is seen a similar process to that 

 in the case of hurricanes, first visible perhaps in the higher 

 strata, but afterwards extending to those which are lower. 



The winds, then, shifted with much regularity, and with 

 them the atmospheric pressure, just as in the case of cyclones, 

 except that neither the wind nor the sea ever presented 

 the characteristics of a tempest. The wind, which began to 

 blow from the North-East, drew gradually to North, thence 



