Il6 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 70 



In the time between 1890 and 1906 it is exactly in the above men- 

 tioned years 1890, 1893, 1899, 1903 and 1905-6, and only in these 

 years that well-marked maxima in the height of the water of the 

 Baltic and the easterly North Sea occurred. 



By means of the winds we may explain in a natural way the 

 agreement between the observed relations in the surface temperature 

 in the Atlantic Ocean and the surface temperature at Liepe's station 

 I near Ouissant, as well in February as for the whole year, and 

 also the agreement with the temperature in Hamburg in February 

 and partially also with the yearly temperature for Hamburg which 

 we have already referred to. 



ARE THE WINDS THE ONLY CAUSE OF THE GREAT VARIATIONS IN 

 THE SURFACE TEMPERATURE? 



But even if we admit the conclusion that the winds are a principal 

 cause of a larger proportion of the great variations of the surface 

 temperature within our investigated fields, there is another question 

 whether these variations are alone due to the winds of the locality 

 or its immediate surroundings. The question can for example be 

 put in this way : Are there not beside the variations in the tempera- 

 ture produced by the displacement of masses of water by the wind, 

 also similar changes produced by water-masses which the currents 

 carry along with them ? 



If this should be the case, then as we have already said, the 

 course of the variations of the values of the surface temperatures 

 minus the air temperature, must be opposite to those which we have 

 found. The transportation of relatively cold water-masses must then 

 cause the surface temperatures of the ocean to come nearer the 

 temperature of the air and the difference between them will con- 

 sequently be less than usual ; and the reverse should happen if the 

 transported water is relatively warm. There arises then the ques- 

 tion if variations of this kind are shown in our observations. That 

 appears as we have said above to be the case in a considerable num- 

 ber of instances. 



If we observe the temperatures in the single years, it appears that 

 the variations in many cases are not alone due to the local winds. 

 For example, this holds for February as also for March-April, 1904, 

 when the temperature over the greater part of the Atlantic Ocean, 

 particularly over the middle parts, became uncommonly low. The 

 isobars and consequently also the winds at that time over our whole 

 observational region had directions which more or less correspond 



