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42 distinct terraces rising from the sea to the South. Although much of the land is very fertile, yet, as the rainfall is uncertain, and often at long intervals, this district is not well fitted for agriculture; but as there is water for stock, and the natural grasses are permanent, it has become one of the most important grazing districts in the Colony.

The sources of the Gascoigne and Ashburton may he 1500 feet above the sea, and there are many points of considerable elevation about them. Mount Augustus, on the Lyons, was estimated by Gregory to be 3480 feet in height; here he found porphyritic, schistose, and metamorphic sandstone rocks; and the ridges, which separate the head waters of all the rivers, are commonly highly siliceous. Plutonic and erupted rocks, diorite, trap, and basalt have been also noticed by explorers in many parts of their valleys.

The Ashburton has a course of nearly 200 miles to the sea, and is 100 yards wide at the mouth, with deep water, but has no safe anchorage. It receives two considerable affluents on the right, Hardey River and Duck Creek, and has good alluvial land and well-grassed plains throughout its course. The upper basin may be 75 miles in width. The Fortescue may be in extent equal to the Ashburton, but has no considerable affluent; this river has much richly grassed country throughout its course, especially below Hamersley Range, which culminates in Mt. Pyrton, 2700 feet above the sea, and from the flanks of which a stream of fresh water, known as the Mill stream, debouches through a gorge. Here first are seen the palm-trees of the North coast. To the North-East of this river, about the sources of the Sherlock and Yule, plains covered with spinifex are found, which again extend beyond the