124 Q. G. Hubbard — Air and Water, Temperature and Life. 



slope toward the east and south with a climate growing contin- 

 ually warmer, while the Siberian plains slope toward the north, 

 the temperature growing continually colder. The winds in 

 summer blow from the Arctic ocean over these plains to the 

 Altai mountains, while in the winter they blow from the moun- 

 tains to the ocean. There is a slight evaporation from the Arc- 

 tic ocean, but the temperature of Siberia is so low and the 

 summers so short that the plains require comparatively slight 

 rainfall to fertilize them. 



There is a large portion of Asia, Arabia, Persia, Turkestan, 

 including Caspian and 7^ral seas, to Avhich we have not par- 

 ticularly referred because it is entirely outside of the influence 

 of either the monsoon, trade, or other moisture-bearing winds. 

 This territory extends from Arabia northeastward beyond the 

 Lake of Balkash into Siberia, a vast extent of countr}^, larger 

 than Europe — a dry, rainless desert, hot in summer and cold in 

 winter. Part of this region is from six to seven thousand feet 

 above the level of the sea, part below the sea level, yet neither 

 height nor depression makes any difference in this arid land. 

 Formerly sections of these countries were thickly populated. 

 The Aral and Caspian basins were called the " Garden of the 

 world." In Mesopotamia Avere Ninevah, Bagdad and Babylon ; 

 in Persia, Susa and Persopolis. Historians tell us of great 

 cities, flourishing empires, where now is onl}^ a barren and sandy 

 desert. We do not know whether the climate has changed or 

 whether in ancient days the country was thoroughly irrigated, 

 and now through neglect has been buried deep in the sand of 

 the desert. Although four-fifths of Asia are either desert or 

 mountainous land and are only scantily inhabited, two-thirds 

 of the population of the world are found within its borders. 



