This zone gradually shades off into another rather broader where the rainfall is much lower; from ten to twenty inches at most. So the scenery changes as we travel westward until we are lost in the country of the western plains: a great dry lowland not far above sea-level, and drained by slow-moving rivers, the Lachlan, Darling, Murray and their tributaries. The railway runs north-westward, through interminable miles of grass and scrub, until it ends at Bourke, the head of navigation on the Darling. It is the land of the sheep and nothing else. We may gain some idea of the enormous extent of land in this part of Australia, available for pasture or agriculture in some form, by placing upon it for comparison the eastern part of the United States, as in the map which we see here. 26 New South Wales possesses nearly as many sheep as the rest of Australia together, and most of these are to be found on the inland slope of the plateau and far out into the plains, more especially in the Riverina district, between the Murray and the Murrumbidgee. We have left behind us the wheatfield and the reapers; the loaded waggons which we pass, drawn by long teams of 27 horses, are carrying great bales of wool to the railway. We may follow the wool back to the shearing sheds where again all the 28 work is done by machinery; then we go on to the sorting shed, and so to the railway and the showrooms at Sydney, where thousands of samples are displayed for the benefit of the buyers for the 29 markets of Europe. We can see the great flocks of sheep before and after the shearing at the homestead or follow them as they 30 are driven to pasture; and everywhere in this great river plain we find the same thing repeated. The rainfall is not sufficient for agriculture; but in ordinary years it will provide good grass for the sheep; and there is also the drought-resisting salt-bush to eke it out. Sometimes the rain fails, and then there is neither food on the ground nor water in the creeks and pools, and millions of sheep die, as in the great drought of 1901-2. The dry climate gives the best wool in the world, but it is not without its drawbacks; though the large profits made by the farmer in ordinary years more than compensate for an occasional period of drought.