HORN EXPEDITION — NAKRATIVE. 9 



ytai'tiiig fi'oni Lake Eyre, .and travelling northwards towards the centre of the 

 continent the traveller passes across a tract some four or live hundred miles in 

 width which may again ha divided into two districts, which may be called 

 respectively the LOWER STEPPES and the HIGHER STEPPES. 



Tlie LOWER STEPPES extend ovei- the area occupied hy tiie great Cretaceous 

 formation with its alternating stony or gibber plains, loamy Hats, and lowdying 

 terraced hills capped with Desert Sandstone. At Lake Eyi'e the land is thirty- 

 nine feet below sea level, and gradually rises to a height of one thousand feet at 

 its northern limit. 



The HIGHER STEPPES are characterised by high ridges of Ordovician and 

 Pre-Cand)rian locks which stretch across the centre of the continent from east to 

 west for some four hundred nnles. The average elevation of these Higher Steppes 

 may be taken as about two thousand feet, and above them the higher peaks of the 

 ridges rise for some two thousand five hundred feet more. 



Both the Lower and the Higher Steppes, as already .said, are traversed by 

 creeks and rivers which are absent in the true Desert Country. In the following 

 account the Lower Steppes are described in the chapters dealing with the country 

 between Oodnadatta on the south and the James Range on the north, and the 

 Higher Steppes in the chapters dealing with the James, George Cill, and 

 McDonnell Ranges, and the Desert Region in the chapters describing the j(jurney 

 from the George Gill Range across I^ake Amadeus to Ayers Rock and Mount 

 Olga. 



The remarks of Brehm* are exactly applicable to the centre of Australia. 

 He says, " In order to understand the steppe lands it is necessary to give a rapid 

 sketch of their seasons. For every country reflects its dominant climate, and the 

 general aspect of a region is in great part an expression of the conilicting foi'ces of 

 its seasons, apart from which it cannot be understood." 



Now the climate of Central Australia is one which reveals an alternation of 

 short rainy seasons with intervening periods of drought. The rainy season is short, 

 the dry season long, and not only this but, whilst the rain season is always short the 

 dry season may be abnormally prolonged. There is no regular succession of spring, 

 sunnner, autumn and winter, but simply a hot and a relatively cold season, that is 

 a summer and a winter with a longer or shorter interval during the former when 

 the rainfall takes place. 



* " From North I'ole to the Equator." EiiyUsli translation hy Maryaret M. Tlionison, p. lUI). 



