292 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 70 



summer. The winter maximum is, however, predominating, and 

 taking the mean distribution of pressure during the whole year 

 there is a barometric maximum over central Siberia, and Mongolia, 

 south of Lake Baikal. 



The pressure curve for Ekaterinburg (fig. 107, IX) shows in 

 most years more similarity to the pressure curve of Ponta Delgada 

 than to the inverted curves for Batavia and Bombay. 



It was mentioned in chapter X that according to Blanford's in- 

 vestigations the winter pressure in western Siberia and Russia 

 changes inversely as the pressure in the Indo-Malayan area, while 

 the summer pressure, especially at Ekaterinburg and Barnaul, varies 

 greatly in the same direction. 



In figure 109 we have given the barometric curves, smoothed by 

 twelve-month means, for seven stations in different regions of 

 Siberia and eastern Russia, east of the Ural mountains. The curves 

 give the departures from normals computed for the thirty years 

 from 1877 to 1906. 



These curves show that the barometric changes are much the 

 same over the greater part of eastern Russia and western Siberia. 

 The curves from eastern Siberia, for Irkutsk and Nerchinskii 

 (curves VI and VII) differ, however, somewhat from the others. 

 The barometric curve for Irkutsk (fig. 109, VI) exhibits a remark- 

 able and rather doubtful difiference between the barometric values 

 before and after 1887. The exceptionally great maximum in 1877- 

 78 seems especially suspicious. It may, however, be noteworthy 

 that at this time there was a striking disagreement between the 

 Atlantic curves (Ponta Delgada, fig. 107, III) and the curves of 

 the Indian Ocean and South America, as was mentioned before. 



The total pressure of the atmosphere being constant, an increase 

 of pressure in one region of the globe must be counterbalanced by 

 a corresponding decrease in other regions. Our investigations 

 seem to indicate a certain regularity in the barometric fluctuations 

 in this way: that an increase of pressure in one high-pressure 

 region coincides more or less with simultaneous increases in other 

 high-pressure regions of the globe, and with simultaneous decreases 

 of pressure in the low-pressure regions, and vice versa. 



We have found that the barometric fluctuations of the Icelandic 

 pressure minimum coincides as a rule not only with the barometric 

 fluctuations of the low-pressure regio'n of the Indian Ocean and the 

 Indo-Malayan region, but also with those of Australia, where there 

 is, to some extent, a high-pressure region. 



