20 



SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 70 



ruary). In the western part it behaves oppositely, for the average 

 is, on the whole, colder in February than in March-April. We 

 shall return to speak of the temperature distributions from decade 

 to decade, but here we mention briefly the other curves of figure 10. 

 The air temperature shows geographical changes similar to those 

 of the water temperature. The " wedge " is very marked, with a 

 temperature maximum on either side. While this " wedge " (at 

 about 49° west longitude) has the same situation in the air as in 

 the water, there is a small difference in the position of its maxi- 



I U 



DEKABE 



m Y 



u m 



i2° - 



n' - 



- 2- 



Figure ii. The curves represent the mean values for each decade (I-VII) 

 for our combined '2° fields along the curves Channel to New York. W : sur- 

 face temperatures ; L : air temperatures, the scale on the right ; W-L : surface 

 temperatures minus air temperatures, scale on the right. 



mum. For example, the greatest air temperature maximum of 

 February lies at about 39° west longitude and is 11.8° C. and in 

 March-April at 35° west longitude with a temperature of 11.9° C. 

 The most westerly maximum, which is much less marked in the 

 air than in the water, lies at 53° west longitude in February with 

 a temperature of 9.2° C. and at 55° west longitude March-April 

 with a temperature of 10.2° C. There is, therefore, a pretty well 

 marked difference of temperature between the two decade groups, 

 so that the February decade is considerably the colder. 



