A close-grained sand stone, nearly resembling that of Pellew's Group, seems to form the basis of Groote and the neighbouring islands; we found also coral, ironstone, and quartz. In many places, quartz in almost a crystallised state was sprinkled in grains through the sand stone, and in others, the sand stone itself was partly vitrified. Wherever we landed, the surface was so entirely composed of stone and sand, that the idea of any kind of cultivation could in no wise be assimilated with it; the hills at a little distance from the water side were, however, well covered with wood, and it is not improbable, that there may be vallies in the central parts of Groote Eylandt possessing some degree of fertility. The central hill, which is six or eight hundred feet in elevation, appeared to be not so much as three leagues from the head of North-west Bay, and I was desirous to have made an excursion to the top, to see the interior of the island; but the state of the ship being such as to press us forward with all practicable haste, it was not attempted; nor did I stop to examine particularly the head of the bay, since it appeared to be shallow, and of little interest to navigation. The wood on Groote Eylandt was mostly composed of different species of _eucalyptus_; the trees were small, and might do for fire wood and very common purposes, but did not seem calculated for any superior use. Chasm Island was the sole place where the nutmeg was found, though in general, the gleanings of the botanists were tolerably fortunate. None of the native inhabitants were seen, nor any kangaroos or other quadrupeds; and birds seemed to be scarce. Small quantities of water, deposited in holes of the rocks by the late rains, were useful to the seamen for washing their clothes; but we did not find any from which a ship could be supplied, nor were there any beaches convenient for hauling the seine. The _latitude_ of Finch's Island, from a meridian observation to the north and south, is 14° 43' 31" S. _Longitude_ from six sets of distances of the sun east of the moon, taken by myself, 136° 38' 47", and from twelve sets by lieutenant Flinders (see Table V. of Appendix No. I), 136° 23' 38"; but there being no observations of the moon at Greenwich within two or three days, the longitude from survey and the position of Caledon Bay afterwards fixed, is preferred, and is 136° 36' 53" E. _Dip_ of the south end of the needle, 39° 22'. _Variation_ of the theodolite, 3° 6' east. The variations of the surveying compass, from amplitudes taken near different parts of Groote Eylandt during the circumnavigation, were these:-- Near the main, opp. the S.W. Pt., head E. by S., 0° 43', cor. 2° 44' E. Near the south-west point, S. E., 1 9 , cor. 2 36 Off the east side, N. E. by N., 2 57 , cor. 4 4 Near the north-east isles., N. W. by W., 3 33 , cor. 1 58 Off the north end, S. W. by W., 5 51 , cor. 4 14