6 3 6 



ZONES AND REGIONS [Pt. Ill, Sect. II 



is less poor in rain and of a grassland character, so that clay soil or clayey 

 loam becomes covered with steppe ; as soon, however, as the soil becomes 

 more permeable, the still very moderate rainfall is no longer sufficient for 

 steppe, and the desert character becomes more or less typically developed. 

 This is in particular the case in the so-called ' Bad Lands' of South Dakota 

 and Nebraska, and the Llano Estacado of New Mexico. 



Desert Climate. 



NORTH AMERICA. 



MEAN MONTHLY RAINFALL IN INCHES AT TEN STATIONS. 



California: Barstow, Bishop Creek, Camp Cady, Camp Independence, Daggelt, Fenner, 



Keeler, Needles. Nevada : El Dorado Canon. Arizona : Yuma. 



Year: 5-515 inches = 13-09 cm. 



CONDITIONS OF TEMPERATURE IN UTAH AND SOUTH-WEST 



ARIZONA. 



DEATH VALLEY (California, Furnace Creek). 



36° 28' N., 116 51' W., about the sea-level. 



(From Meteorol. Zeitschr., 1893, p. 23.) 



According to observations taken in the afternoon, from the 30th July to the 9th 

 August the relative humidity did not rise above 13 per cent., the mean was 8 per cent. 

 Absolute minimum of the relative humidity, 5 per cent at 44 C. Probable annual 

 rainfall, 114 mm. 



