202 OF WINDS. CHAP. 6. 



I have lately remarked a circumstance with 

 regard to the change of Winds, which I have 

 never heard mentioned by meteorologists, and 

 which may therefore be worth noticing. I have 

 observed, that when the current next the Earth 

 has changed its direction, it has frequently got 

 into and blown from the quarter from which 

 an upper current had previously blown. I was 

 first apprized of this, by observing the motion 

 of an upper stratum of clouds to be different 

 from that of those which were lower ; and by 

 the lower clouds afterwards taking the direction 

 of those above : but as I had few opportunities 

 of observing this circumstance, I thought it 

 merely accidental. Subsequent observations 

 on the various directions of Air Balloons, and 

 the succeeding changes of the Wind, have 

 convinced me that it is frequently the case, that 

 the changes of the Winds begin above, and are 

 propagated downwards. And I have observed 

 this of several successive currents. 



Persons who are desirous of making these 

 observations, should have Windvanes accu- 

 rately constructed, and should compare their 

 indications with those of the clouds above. 

 Weathercocks should be made with a ball of 

 oil at the top, so constructed as to keep dropping 

 into the circular cylinder on which the fan 



