The brig Porpoise, part of the U.S. Exploring Expedition, sailed through frigid Antarctic waters on 30 January 1840, off a seemingly impenetrable wall of ice. That afternoon, sailors topside sighted two ships in the distance. Suspecting them to be the sloops Vincennes, flagship of the expedition, and her consort Peacock, Lieutenant Cadwalder Ringgold, the Porpoise’s commander, ordered his ship to close them. As the distance diminished, however, the vessels broke out French colors; the larger of the two, the Astrolabe—flagship of Captain Jules-Sébastien-César Dumont d’Urville—wore a commodore’s pennant.
Historic Fleets - 'Admirably Fitted for the Performance of Her Duty'
By Robert J. Cressman