The map of Matarai, and of the bay which bounds it on the north-east, completed by us with the utmost care from trigonometrical surveys, is attached to this volume, and renders any further description of the coast it embraces unnecessary. In December and January, the Tahaitian summer months, the trade-wind is often interrupted by violent north-westers. Rain and storms are then frequent, and often last till April; in the other months the trade-winds blow without intermission, and the sky is always serene. For this reason, what is here called the summer, might pass for the actual winter; and as the roads of Matarai are open to the west wind, it is advisable for ships visiting Tahaiti at this season, to run into the harbour, which lies eight miles west of Venus Point. It is spacious, formed by coral reefs, protected against all winds, and has two entrances so convenient, that ships may sail either in or out with almost any wind. The ebb and flow of the tide in the Matarai Bay differs entirely from the ordinary rules, and appears wholly uninfluenced by the moon, to which it is everywhere else subject. The rise and fall is very inconsiderable. Every noon the whole year round, at the moment the sun touches the meridian, the water is highest, and falls with the sinking sun till midnight. This phenomenon serves, as well as the sun's motion, to supply the place of clocks to the inhabitants. According to Humboldt, the altitude of the highest mountain in Tahaiti is ten thousand feet; according to the barometrical measurement of Mr. Long, only eight thousand feet above the level of the sea. Our first observation by chronometers, on our arrival at Matarai, gave the longitude of Venus Point as 149° 20' 30"; the true one, as given by Admiral Krusenstern on his map, is 149° 27' 20"; consequently, the error of our chronometers was 6' 50". This correction has been made in all the longitudes taken by us in the dangerous Archipelago. From our observatory on Venus Point, we found its latitude 17° 29' 17", and its longitude 149° 29'. The variation of the needle was 6° 50' east, and its inclination 29° 30'. The barometer ranged from 29' 80" to 29' 70"; Reaumur's thermometer from twenty-three and a half to twenty-four and a half. The islands which I discovered on my former voyage in the ship Rurik,--the Romanzow, Spiridow, Dean's Islands, the Rurik's Chain, &c. whose longitude I had not then an opportunity to rectify upon Venus Point, lie 5' 36" more to the west than I at first supposed. The longitude given by Captain Bellingshausen for the island which he discovered, appeared to us by 3' 10" too great.