We passed, at midnight, within 60 miles of the position assigned in the chart to the low coral group known as Houtman's Abrolhos,* and again sounded unsuccessfully with 200 fathoms.
(*Footnote. Subsequent observations placed these islands 30 miles more to the eastward than the position there assigned them. Our track, therefore, was really 90 miles from them.)
We continued steering a northerly course up to the 9th, keeping within from 60 to 80 miles distance of the coast, and repeating our deep-sea soundings every six hours without success.
INDICATIONS OF A SQUALL.
The wind during each day was moderate from the South-South-West and South by West, freshening during the night from South, and South by East; a heavy swell was its constant companion, and the barometer fell to 29.75. On the morning of the 9th, being in the parallel of North-west Cape, our course was altered to North-East by East; it blew hard during the night, and we had a disagreeable sea; but, as usual, it moderated again towards the morning.
We had shaped a course to make a reef in latitude 20 degrees 17 minutes, and named after its discoverer, Lieutenant Ritchie, R.N.; but owing to its being situated, as we afterwards found, half a degree to the eastward of its assigned position in the charts, we did not see it.
At 4 A.M., and with 195 fathoms, we reached a bottom of sand, broken shells, and coral, being then about 80 miles North-North-East from Tremouille Island, the nearest land. Steering East by North 1/2 North for 31 miles, brought us to our noon position in latitude 19 degrees 20 minutes South, longitude 116 degrees 16 minutes East, and into a depth of 120 fathoms, with the same kind of bottoms. South-South-West, 17 miles from our morning position, Captain King had 83 and 85 fathoms; from this we may suppose the edge of the bank of soundings, extending off this part of the coast, to be very steep. These soundings, together with those of Captain King, as above, may give some idea of the nature and extent of this bank, which seems to be a continuation of the flat extending North-North-East 40 miles, connecting Barrow and Tremouille Islands with the main: its outer edge being kept heaped up thus steeply by the constant action of the current sweeping round the North-west Cape.
DEEP SEA SOUNDINGS.
We continued steering East and by North 1/2 North, and at sunset, 14 miles from our noon position, the water had deepened to 145 fathoms, bottom a fine white sand and powdered shells. Before we were 50 miles from our noon position, we could find no bottom with 200 fathoms.
January 12.