In the evening we anchored a mile from the South-West side of a small detached reef, marked F in the chart, and distant 22 miles from Cape Flinders; the solitary position of this reef, it being four miles from the inner edge of the Great Barrier, and nine from the nearest part of the main, gave us a good opportunity of making a section, with a view of illustrating the progressive structure of coral edifices, in the still waters within the barrier reef; we accordingly visited the spot in the evening, and being an interesting object, we give a drawing of the section. It proved a good specimen of the circular or lagoon reef. One young mangrove was growing on the elevated part marked C in the woodcut. The rim which rose on all sides was quite black, but white when broken; the highest part being about three feet above the water. The nature of the bottom within the reef was a white sand mixed with small pieces of dead coral: without, we found on either side soft green sandy mud with shells, the inclination of the bottom on which the reef rests, being only one degree, we may fairly infer it to be superimposed on a most extensive basis. CLAREMONT ISLES. July 7. To-day being Sunday we did not proceed further than Number 4 of the Claremont Isles, a low rocky group encircled by coral reefs, to give the ship's company a run on shore during the afternoon; in order to remind them of its being a day of rest appointed by the Lord. When we anchored, we found, contrary to the usual north-westerly tendency of the current, a tide setting South-South-West three quarters of a knot an hour, this lasted for a space of four hours, when it changed, and ran North-North-West from half to three quarters of a knot during the remainder of our stay. The wind was moderate from East-South-East. July 8. We weighed at 6 A.M., and about the same hour in the evening again anchored under Restoration Island. The ship's track during the day followed the trend of the land, keeping about seven miles from it, except when opposite Cape Direction, where we were about half that distance from the shore. We found little to add to Captain King's chart, with the exception of some reefs lying about ten miles east from the above-mentioned headland. CORDILLERA. The coast here again attained a moderate height, and a round hill ten miles south of Cape Direction, reached the height of 1250 feet; its latitude being 13 degrees South is nearly five degrees and a half north of where the Cordillera is 3500 feet high, and 23 1/2 degrees of where it attains its greatest elevation, that of 6500 feet; a fact which will at once demonstrate the northerly tendency in the dip of the chain of hills. This degree is further illustrated by the height of Pudding-pan Hill in 11 degrees 19 minutes South being only 384 feet. From the data given, despite the limited number of our facts, it will be seen that the dip becomes gradually more rapid as you advance to the northward.