NO. 4 TEMPERATURE VARIATIONS IN THE NORTH ATLANTIC 21 5 



curves also run in opposite directions. A comparison of the promi- 

 nence curve and the air pressure of Batavia for the same interval 

 of time gives about the same results except that the prominence 

 curve shows no maximum in the years 1903-4 corresponding to 

 the minimum of air pressure. The maximum of the magnetic 

 curve in the year 1910 corresponds to a maximum three-quarters 

 of the year earlier in the prominence curve. 



In consequence of the above mentioned phase displacement of 

 several months in the air pressure curves of the four stations of the 

 Indo-Malayan region in relation to one another, there is some dif- 

 ference between the agreement or lack of agreement of these curves 

 with the magnetic curve or the prominence curve, but on the whole 

 they show in spite of it the same relations. 



Consequently we see that, as regards the periods of a few years, 

 there is no certain agreement between the air pressure variations 

 and the variations in prominences as was announced by the two 

 Lockyers. At certain isolated times, as we have seen, the air pres- 

 sure goes directly with the prominences and at other times op- 

 positely to them. The same thing is found if we compare the air 

 pressure variations with the variations in the disturbance of the 

 magnetic elements as observed in Potsdam. Considering Batavia 

 and the Indo-Malayan region it appears as if in general they go 

 oppositely to one another. 



As for the air pressure variations at the two other tropical sta- 

 tions given in figure 71, namely. Port au Prince and Fort de France, 

 there cannot be found here either any fixed rule for agreement 

 between the air pressvire variations and the variations in the promi- 

 nences and the magnetic elements. In the most cases it appears 

 that the air pressure in these stations goes directly with the promi- 

 nences and magnetic elements, but with some displacement of phase. 

 This shows particularly well in a comparison between the curve for 

 air pressure at Fort de France (fig. 71, VI, B) and the curve for 

 the disturbance of the magnetic elements at Potsdam (M). 



THE RELATION BETWEEN TEMPERATURE VARIATIONS AND 

 VARIATIONS IN SOLAR ACTIVITY 



Examining now the variations in the temperature at these tropi- 

 cal stations more closely we find that in consequence of the earlier 

 mentioned displacement in the air pressure variations in relation to 

 those of temperature, the latter behave somewhat differently with 

 regard to the variations in the prominences and magnetic elements. 



