Turning south thumb|upright=1.3|Reconnaisance de la Terre Adelie, 20 Janvier 1840 ("Reconnaisance of Adelie Land, 20 January 1840") The first days of the voyage mainly involved the crossing of twenty degrees and a westerly current; on board there were further misfortunes, including the loss of a man. Crossing the 50°S parallel, they experienced unexpected falls in the air and water temperatures. After completing the crossing of the Antarctic Convergence, on 16 January 1840, at 60°S they sighted the first iceberg and two days later the ships found themselves in the middle of a mass of ice. On 20 JanuaryInstead of 19 January 1840, since Dumont d'Urville forgot to add one day on his diary when he passed the 180° meridian from the east, Proposition de classement du rocher du débarquement dans le cadre des sites et monuments historiques, Antarctic Treaty Consultative meeting 2006, note 4. the expedition crossed the Antarctic Circle, with celebrations similar to crossing of the Equator ceremonies, and they sighted land the same afternoon. Voyage au Pôle sud et dans l'Océanie sur les corvettes "l'Astrolabe" et "la Zélée", exécuté par ordre du Roi pendant les années 1837-1838-1839-1840 sous le commandement de M. J. Dumont-d'Urville, capitaine de vaisseau, Paris, Gide éditeur, 1842–1846, tome 8, p. 136-181, site of Gallica, BNF.
Turning south thumb|upright=1.3|Reconnaisance de la Terre Adelie, 20 Janvier 1840 ("Reconnaisance of Adelie Land, 20 January 1840") The first days of the voyage mainly involved the crossing of twenty degrees and a westerly current; on board there were further misfortunes, including the loss of a man. Crossing the 50°S parallel, they experienced unexpected falls in the air and water temperatures. After completing the crossing of the Antarctic Convergence, on 16 January 1840, at 60°S they sighted the first iceberg and two days later the ships found themselves in the middle of a mass of ice. On 20 JanuaryInstead of 19 January 1840, since Dumont d'Urville forgot to add one day on his diary when he passed the 180° meridian from the east, Proposition de classement du rocher du débarquement dans le cadre des sites et monuments historiques, Antarctic Treaty Consultative meeting 2006, note 4. the expedition crossed the Antarctic Circle, with celebrations similar to crossing of the Equator ceremonies, and they sighted land the same afternoon. Voyage au Pôle sud et dans l'Océanie sur les corvettes "l'Astrolabe" et "la Zélée", exécuté par ordre du Roi pendant les années 1837-1838-1839-1840 sous le commandement de M. J. Dumont-d'Urville, capitaine de vaisseau, Paris, Gide éditeur, 1842–1846, tome 8 p. 136-181, site of Gallica, BNF.