505 



combined must have made the strong wind of the gales a very unpleasant experience, and it is quite 

 possible that that fact may have led unconsciously to some amount of exaggeration in estimating the force 

 of the wind at such times. 



CHANGES OF TEMPERATURE AM> OF WIND. 



Sudden large changes of temperature were of frequent occurrence at the Winter Quarters, and an 

 attempt has been made to correlate them with changes in the direction and velocity of the wind. It was 

 found that in 17 per cent, of the instances in which such a sudden rise in the temperature occurred, and 

 in 19 per cent, of those in which it as abruptly fell, the movement was not accompanied by any change 

 either in the direction or force of the wind. 



When the change of temperature coincided with the springing up of a wind after a calm, the tempera- 

 ture nearly always rose, and, indeed, the only exceptions to this rule occurred when the temperature 

 change between the two observations amounted to less than ten degrees ; in no case when the rise in 

 temperature exceeded that amount did it accompany a falling away of the wind force to a calm. On the 

 other hand, the large and sudden decreases of temperature almost as generally coincided with the dying 

 away of the wind force to calm. 



Table XIII. gives the number of instances in which these rapid changes of temperature were 

 accompanied by a change from a wind to a calm, or vice versa, and also the direction of the wind when its 

 force fell or when it sprang up. In both cases the direction was most frequently, but not invariably, 

 northerly ; several of the larger increases of temperature occurred with the advent of an easterly breeze, 

 and in one or two cases the wind came from south. 



3 T 



