We can travel now by railway along the coast strip to Newcastle, 13 then up the valley of the Hunter, and finally climb the Liverpool Range on to the plateau beyond. But the journey was far from easy for the early settlers. In fact, until 1820, when a stock route was discovered from Sydney to Newcastle, the only intercourse with the north was by sea, and Newcastle grew up almost as a separate colony in consequence. The valleys of the Hunter and other rivers gave a natural direction to early settlement, since in their lower courses they flow through wide alluvial flats which are very fertile and easy to cultivate. But they are subject sometimes to devastating floods, as the settlers found to their cost, while the heavy summer rainfall is not well suited to certain of our crops, such as wheat. So in the early days the colony was often in difficulty as to its main food supply. The name Newcastle at once suggests coal; and coal is everywhere in this district. The surface of the country round Sydney is largely a barren sandstone; but underlying the whole of the area, from Newcastle on the north to Bulli on the south, and extending westward to the other side of the plateau edge, is a vast coalfield. Its chief development at present is around Newcastle. Here is a view of Hetton colliery, Newcastle; both the name and 14 the picture remind us strongly of the North of England. We see the coal being wound up from the shaft as in our own mines, and in the distance vessels lying at the wharves in the fine harbour. Here again is a general view of the harbour in which we can 15 clearly distinguish the loading of the coal and merchandise. A journey southward from Sydney to the other end of the coalfield will bring us to a less familiar type of mine. At Clifton the early explorers found coal strewn on the beach; the actual seam is in the face of the cliff, and shows as a broad black band, 16 while the coal is mined by means of adits, and then run on to the little pier to be shipped. The coal is found under Sydney itself, and mining is now in progress on the south side of the harbour; but the shafts are much deeper here than at Newcastle, since the coal measures lie in the shape of a saucer, and Sydney is near the middle. We may notice here that the southern railway line ends at Nowra on the Shoalhaven river, and beyond are only a few small coast towns; so we need not at present explore further in this direction.