1868.] 



Exploration of Central Australia, 



349 



centre, which embraces nearly the whole of the country discovered and 

 examined since 1860. 



From the records of the various explorers, it would appear that the line 

 which divides the waters flowing to the coast, and those flowing to the in- 

 terior, runs from 19|° S. on Stuart's track to 19° S. latitude on Lands- 

 borough's south-west expedition, in 138° east longitude. According to 

 ]Mr. M'Intyre's apparently reliable observations, this line would then pass 

 through 22° S. in 141|-° E., whilst JM'Kinlay places in the same locality 

 the watershed between the Middleton and Miiller rivers, in a latitude but 

 slightly differing from that just named; and in Vfalker's Diary we find it 

 passing through 21^° S. and 145° E., where I find the highest elevation 

 recorded by the latter explorer on his expedition in search of Burke and 

 "Wills. Mr. A. C. Gregory's exploration places the continuation of this 

 line of watershed through the north-west in 13° S. and 130° E., whilst in 

 the east it meets the main watershed between the Belj^ando and Thomson 

 on the one side, and the Burdekin and Flinders on the other, in about 21° 

 S. and 145|° E. (See accompanying map.) The sweep of this line leads 

 across a sandstone tableland of considerable elevation — in parts even as 

 high, if we may rely on the data hitherto collected respecting it, as 1900 

 or 2000 feet. On its coast side this tableland inclines somewhat abruptly, 

 whilst towards the interior it slopes more gently, thus affording a ready 

 explanation of the marked difference existing between its river- systems, 

 those flowing in the former direction passing through well-defined valleys, 

 while those in the latter direction run generally in shallow beds, and are 

 consequently subject to excessive evaporation and inundation according to 

 the season of the year. The general incline of the country from longitude 

 145° to Stuart's track in about 135° is towards south-west, until reaching 

 near the latter its lowest point, as we feel justified in concluding from the 

 great number of hot springs on the route Stuart pursued when crossing the 

 continent. This immense tract of land abounds in creeks and ilh defined 

 water-courses. In many cases the dividing or separating ridges of sand- 

 stone are (probably from the effects of floods and weather) broken up, and 

 cover the surface, which then presents a desert-like appearance, only here 

 and there covered with a scanty vegetation, consisting mostly of Spinifex 

 {Triodia irritans). Very frequently, however, these ridges have succeeded 

 in resisting the destroying effects, and we then meet with valleys of good 

 soil, covered with fine grass and gum forest ; which state of things, hap- 

 pily for the future of the Australian continent, seems to predominate, as 

 we learn from the reports of explorers who passed through fine country 

 after having once entered the tropic. These water-courses of the interior 

 basin drain partly towards the Barcoo River (Cooper's Creek), partly to- 

 wards the south, splitting up into innumerable little creeks and rills with- 

 out any definite direction. As an example of the latter kind may be men- 

 tioned the Burke Creek, which at times causes immense inundations in the 

 tract of country near 25° S. and 140° E., as we learn from the reports of 



