Narrative of the surveying voyages of his majesty's ships Adventure and Beagle (vol.2- Appendix): between the years 1826 and 1836 : describing their examination of the southern shores of South America, and the Beagles's circumnavigation of the globe

286 APPENDIX. time of high water. Both cannot be right : but thinking the latter correct, I have preferred it. In Bass Strait it is high water at about ten. Between the two extremes there are thirteen hours, and between the times of tide there are eleven, or thirteen hours. At Amsterdam Island, high water is taken as two hours after that of Bass Strait, but the difference of meridians is about four hours. The difference between the high water of Amsterdam, and Blanco Bay, is nine hours, and their difference of meridians is about nine hours. In 30° S. it is high water on the African coast at two, and on the American coast at six. There are about four hours difference of meridian between them in that parallel. In 20° S. it is high water at 3h. on the African shore, and 6h. on the Brazilian ; the meridian distance is about three hours and three quarters. In 10° S. at 3h. 15m. on the east side and 7h. on the west: the distance is about three hours and a quarter. On the equator we have 4h. 30m. at the eastern limit, and nearly 8h. at the western ; the distance being about three hours and a half. In 10° N. 7h. and lOh. the distance being three hours. In 20° N. at Cape Blanco, at about Ih. ; and on the north coast of San Domingo, nearly at 11 h. The interval is about 3.40 : but there are interfering derivative tides, probably, as well as local pecu- liarities, among the West-India Islands. In 30° N. about 4h. on the east and Ih. 30m. on the west. The distance is nearly five hours. This seems anomalous. In 40° N. 3h. on the coast of Spain, and at about Ih. on the coast of America. This is another anomaly : but easy of explanation. In 50° N. it is high water at 4h. 36m., in the mouth of the chan- nel ; and at lOh. 45m. on the coast of Newfoundland. Their meridian distance is about 3.20. On the west coasts of Ireland and Scotland, from 5h. to 6h. is the hour of high water ; on the coast of Labrador, it is from lOh. to llh., in the same parallels. The meridian distances are from three to four hours : but as we approach the parallel of 60° N. the North Sea and Davis Strait open, which probably affect the tide between Ireland and Labrador. The Indian Ocean appears to have high water on all sides at once, though not in the central parts at the same time. Thus, it is liigh water at the north-west extremity of Australia ; on the coast of 1