This bay is unnoticed in the Dutch chart, and I name it MELVILLE BAY, in compliment to the Right Hon. Robert Saunders Dundas, viscount Melville, who, as first lord of the Admiralty, has continued that patronage to the voyage which it had experienced under some of his predecessors. It is the best harbour we found in the Gulph of Carpentaria; the entrance is from the N. N. W., four miles wide, and free from danger; and within side, the sole dangers not conspicuous, are a sandy spit running half a mile to the S. S. E. from Point Dundas, and the _Half-tide Rock_. This lies half a mile from the north-west part of Drimmie Head, and bears (true as usual), From the sandy hillock within Point Dundas, S. 48° 35' E. From Harbour Rock, S. 10 39 E. Melville Bay every where affords good holding ground, the bottom being either mud or sand; and there is depth for a ship to run between the three rocks in the middle of the bay and Drimmie Head, and steer eastward until the head is brought to bear N. N. W., at the distance of one or two miles; but the most convenient anchorage is just within the entrance, between Point Dundas and Harbour Rock, where a ship may lie close to the sandy beach in from 3 to 5 fathoms. Even within the rock there is depth enough; and were moorings laid down, four or five sail might swing there in perfect security. We obtained here fire wood, and a tolerable supply of fish; and had water been wanted, it might have been obtained by digging at the foot of the small hills to the north-east of Harbour Rock, since a hole made there by the natives was found to contain good water. The stone on the north side of Melville Bay is a granitic composition of quartz, mica, and coarse garnets; the garnets are large, and give the stone a plum-pudding-like appearance, and when polished, it would be beautiful: over the granite is a crust of calcareous rock in many places. On the south side of the bay the stone is argillaceous, but frequently mixed with ferruginous grains; and on the south-east side the rocks are of iron ore, of which a small piece drew the needle of my theodolite 8° from the meridian. The bearings taken here were found to have been 50° wrong; but too late to ascertain whether the error arose from the attraction of the shore, or from the needle having been placed at 310° by mistake, instead of 360°.