There are two places where ships can ride in safety, Napakiang Roads on the south-west, and Port Melville on the north-west side of the island. The first of these is the one in which his majesty's ships Alceste and Lyra lay for upwards of a month. By means of a base of 1319 feet on a coral reef, which dried at half ebb, we were enabled to make the survey which accompanies this notice. The latitude of the observatory was determined to be 26º 13' 34" north, the mean of three meridian altitudes of the sun by a sextant of Cary's, and five by a circle of Troughton's, the extreme difference being 20". The longitude is 127º 38' east; this was ascertained by measuring the difference of longitude between the observatory and Lintin Island off Canton river in a run of six days; on which occasion two chronometers on board the Lyra gave within one mile the same difference of longitude, viz. 13º 50', with that shewn by two others on board his majesty's ship Alceste; the longitude of Lintin being 113º 48' east of Greenwich. The longitude, by lunar observations, is 127º 37' 28". The plan of Napakiang roads will be found sufficient without many directions for ships wishing to enter it. The principal danger lies in the outer reefs, which do not show when the weather is very fine and there is little swell; on such occasions a boat ought to go a-head at least a quarter of a mile, and the ship should put about instantly upon approaching the reefs, which are every where bold. A ship coming from the westward ought to steer between the north-eastern of the group of high islands to the south-westward, and a low green island with extensive reefs to the northward, in latitude 26º 15' north. On passing which she should haul up east by south, giving Reef Island a birth of at least a mile. [Sidenote: Plan of Napakiang.] [Sidenote: Directions on approaching Napakiang.] [Sidenote: Reef Island.] [Illustration] [Sidenote: Directions for entering Napakiang roads.] [Illustration: NAPAKIANG ROADS _on the S.W. Side of the_ GREAT LOO CHOO Island _Laid down from actual survey by Captain Basil Hall R.N. H.M. Sloop LYRA_ 1816] [Sidenote: Capstan Rock.] [Sidenote: Best anchorage off the mouths of two rivulets.] [Sidenote: The northern entrance.]