A mighty oceanic swell said to precurse the northers of the Atlantic, and felt in great violence at Tristan d'Acunha, where H.M.S. Lily foundered with all hands in consequence, and several vessels at St. Helena have been driven from their anchors and wrecked. These waves roll in from the north, and do not break till they reach soundings, when they evince terrific power, rising from 5 to 15 feet above the usual level of the waters. A connection with volcanoes has been suggested as a cause.