17th September (Sunday).
Light clouds from the south-west; thunder; rain in the evening. Read prayers.
18th September.
Left the bivouac at 8.15 a.m., and followed upwards the main branch of the Irwin to the north-north-east, through a steep and rocky valley, the sandstone hills in some parts approaching the river, so as to render it necessary to cross frequently with the pack-horses. The very level character of the summits of these hills gives the country the appearance of having been once a plain, through which the valley of the stream has since been worn by the action of water; the upper stratum is a hard red sandstone, resting on a softer rock of a sandy or clayey character, beneath which the shales and rocks belonging to the coal formation show themselves, lying in unconformable beds, and often at a very high angle. At 9.25 the stream divided into two branches, that to the east being the most considerable; at this spot the sandstone ceased, and we commenced ascending the granite range, the direction of which was about north-north-west. The soil was poor and stony, producing a little feed for stock; but it could scarcely be made available, as the country is completely covered with thickets of acacia of small growth. At 4 p.m. bivouacked on a small watercourse running through a level grassy flat, bounded on both sides by thickets of wattle.
SCRUBBY COUNTRY NORTH FROM THE IRWIN RIVER.
19th September.
At 8.15 a.m. steered a nearly north course, through a country of the same description as yesterday; crossed several small gullies trending west, in some of which a little water still remained; at 4.20 p.m. halted for the night at a brackish pool in a small gully trending west.
20th September.
Started at 8.0 a.m., continuing a northerly course, over a similar description of country as during the past two days, crossing three large gullies coming from the eastward, but apparently near their source. At 3.45 halted on a large stream-bed, with a few brackish or rather salt pools in its sandy channel, which was in some places nearly 100 yards wide; from our encampment we observed a very remarkable peaked hill, distant about twenty miles, and from its outline conjectured it to be composed of the same vein of trap-rock as that which forms similar ranges further to the eastward.
21st September.