Blue-mud Bay.] 
TERRA AUSTRALIS. 
199 
partly argillaceous, and in part sand stone, with a mixture in some isos, 
places of iron ore, but more frequently of quartz. A little soil is Saturdays? 
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 
tiecs and coarse grass, which the late rains had caused to look fresh 
and green , there were a] ( so some temporary drains of fresh water. 
I he latitude of the hummock at the east end of IVlorgan's 
Island, is 13 0 27 i-', and longitude from the survey, 136° g 'J. Azimuths 
observed at the anchorage, with three compasses and the ship's head 
in the magnetic meridian, gave 2 0 23' east variation, which corres- 
ponded very well with the bearings. The tides here are very in- 
considerable, 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 north- 
ward; 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 
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