148 F. Waldo — Bruckner $ Klim&schwankwxgen. 



deepening of the constant cyclone which the annual means 

 show for the North Atlantic Ocean ; (2) an increase of the 

 high pressure which extends from the Azores to the interior of 

 Russia ; (3) a deepening of the low pressure in the northern 

 part of the Indian Ocean and China Sea ; (4) a decrease of the 

 high pressure which exists, for the yearly means, over Siberia ; 

 (5) a general increase of the amplitude' of the annual oscilla- 

 tion, which causes in the dry period in winter a relatively high 

 pressure in Europe and Siberia and a relatively low pressure 

 over the North Atlantic Ocean ; and in summer a relatively 

 low pressure in Central and Western Europe and on the isorth 

 Atlantic Ocean. 



s, C 1826-30 31-35 36-40 41-45 46-50 51-55 56-50 61-65 66-70 71-75 76-80 81-85 



o Pressure... +-08 '92 '02 —-29 — -19'— "35 -17 -42 — 02 -10 —-33 -34 



Eainfall 



r 





Pressure 



< ' Rainfall 



^ r 



Pressure 



ii 



1 —10 -1 4 1 4-4 -10 10 6 



■08 —'IS '54 -51 --If 



-•12 --13 



■32 --73 



| Rainfall ... 



I 



12 3 5 2-6 -10 



•23 00 -'09 —-04 --46 --49 —-08 -09 -24 

 24 31 1 13 -34 24 14 54 74 



35 I 



Pressure _ .. 



Rainfall ... 



26 



•45 _-06 —-04 —-10 —-45 



15 -20 -10 



'29 



■22 



23 28 



I 



Each rainy period is, then, accompanied by a smoothing out 

 of all differences of air pressure, and each dry period by a 

 sharpening of them, not only for annual averages from place 

 to place but also for the seasonal averages at the same place. 

 But it is to the amounts and directions of the gradients of air 

 pressure that we owe the general rain-fall conditions, and it is 

 to these long period oscillations of air pressure that we owe 

 the simultaneous long oscillations of rain-fall. We need, how- 

 ever, a similar comparison for other portions of the globe 

 before these relations can be said to be completely proven to 

 have a general applicability. 



Temperature. — The much more intimate temporary relations 

 which exists between air pressure and temperature than be- 



