724 wijN^ds of the globe. 



peculiar position towavds the southern seas. They are separated from the Medi- 

 terranean and Adriatic by some high ranges of mountains. If we suppose a N. E. 

 wind at Kischinev, directed towards the Adriatic, it would have first to pass 

 across the Carpathian mountains, and then, besides others, over the high chains of 

 Dalmatia and Bosnia, towards the ^gean Sea where there are also mountains — tlie 

 Balkan chain, leaving but the narrow aperture of the Bosphorus, where a N. E. wind 

 prevails during the year.' Hungary even, though situated to the S. W. of the 

 Carpathian, has high mountains intervening between it and the Adriatic. Toward 

 the Black Sea the air can arrive more easily along the Danube. There are also 

 some low though narrow passes between Transylvania and Wallachia. Thus we have 

 here a region of high pressure in winter, with a comparatively warm sea lying 

 towards the E. and S. E. The movement of air in this direction is easy. The result 

 is a prevalence of N. and N. W. winds, as shown by the map, Plate 6. 



In the summer the pressure is low in the interior of the continent and very high in 

 the western Atlantic, between 30° aijd 40° N. West winds are the result of this. It 

 was shown that they prevail in Germany and Switzerland, and the further east- 

 ward the more this must be the case. Thus we have the air from the Atlantic 

 flowing over the Mediterranean as a north wind towards the depression in Africa, 

 and over the Carpathian region as N.AV. towards the Asiatic depression. (See Plate 5.) 



In autumn, especially in September and October, the conditions change. Central 

 Asia is already much cooled, pressure has risen there, but in Africa and western 

 Asia there is still a region of low pressure, somewhat to the south of where it was 

 in summer. This causes a more rapid movement of air southward and southwest- 

 ward, even near the Black Sea, and a greater prevalence of N. E. winds than at 

 other seasons, as shown by the maps. Plates 7 and 9. Pressure is very high in 

 autumn on the northern shore of the Black Sea, and from thence the N. E. winds 

 begin. This is the season when conditions very like to those of the trade-wind 

 region occur here. And it is also a very dry season, the precipitation diminishing 

 very much from June to October. (See Plate 14.) 



The cause of the smaller prevalence of the N. W. winds in spring may be found 

 in the low pressure which then prevails in the Mediterranean, while it rises in the 

 Arctic regions. In April especially there is less difl'erence in pressure in the 

 northern hemisphere than in any other month. Thus the winds have a less decided 

 character, and local peculiarities are of comparatively greater influence. 



The steppes of south Russia have prevailing easterly winds during about nine 

 months in the year. Only in summer westerly winds take the lead. This regipn 

 is very diiferent from the rest of Europe in this respect, as well as from the greatest 

 part of the temperate zone of America, where westerly winds are the most frequent. 



It was Wesselowski- who brought this fact before the scientific world, and proved 

 it so abundantly that no doubt could be entertained as to its correctness. The winds 

 are easterly in this region in winter, spring and autumn, because pressure is higher 

 to the north and in the interior of the continent. The prevalence of easterly winds 

 ceases in summer (or, more accurately, from the middle of May to the middle of 



' See remarks of Dr. Dwight, p 369. '' lu his work on the Climate of Russia. 



