Page:A Voyage to Terra Australis Volume 2.djvu/209

Blue-mud Bay.]

partly argillaceous, and in part sand stone, with a mixture in some places of iron ore, but more frequently of quartz. A little soil is formed upon the slopes of the hills and in the vallies; and there, more especially at the east end of the island, it is covered with small trees and coarse grass, which the late rains had caused to look fresh and green; there were also some temporary drains of fresh water.

The latitude of the hummock at the east end of Morgan's Island, is 13° 27½′, and longitude from the survey, 136° 9½′. Azimuths observed at the anchorage, with three compasses and the ship's head in the magnetic meridian, gave 2° 23′ east variation, which corresponded very well with the bearings. The tides here are very inconsiderable, and there appeared to be only one flood and one ebb in the day; high water took place about midnight, when the moon was a little past the lower meridian; but whether it will always be so far behind the moon, may admit of a doubt.

A view of the main land to the westward, from Cape Barrow to Mount Grindall, had been obtained from the higher parts of Morgan's Island; but a probability still remaining that some river might fall into the bay, I proposed to coast round it with the ship. On a breeze springing up at E.S.E., early in the afternoon, we steered round the west end of the island, and hauled to the northward; but meeting almost immediately with shoal water, the course was altered for the south-west, and afterwards for the south, part of the bay; and finding no where more than 3 fathoms, we tacked to the N.E. at dusk, and came to an anchor. The bottom here, and in most other parts of the bay, is a blue mud of so fine a quality, that I judge it might be useful in the manufactory of earthern ware; and I thence named this, Blue-mud Bay.

It was evident from the uniform shallowness of the water, that Blue-mud Bay did not receive any stream of consequence, either in its south or western part; and to the north, it seemed not to be accessible from this side. The main land rises very gradually from