In January, 1840, two National Expeditions were in the Antarctic, one the United States Exploring Expedition, consisting of four ships, the Vincennes, Peacock, Porpoise and Flying Fish, under the command of Lieutenant Charles Wilkes, U. S. Navy, and the other a French Expedition, consisting of L'Astrolabe and La Zelee, under command of Capitaine de Vaisseau M. J. Dumont d'Urville.
It has generally been accepted by foreign authorities that d'Urville sighted the land of the Antarctic Continent which he named Adelie Land on the same day (January 19) that Wilkes discovered land four hundred miles to the eastward which he named Cape Hudson, and also that d'Urville's Cote Clarie in longitude 131 East was sighted by him the day before it was seen by Lieutenant Ringgold on board U. S. S. Porpoise.
Investigation shows that both of these assumptions are in error and in fact d'Urville first sighted Adelie Land the day after Wilkes sighted Cape Hudson, and he sighted COte Clarie the same day that it was sighted by Ringgold, but at a later hour. The story of the investigation which led to these conclusions will be given in the order in which it was made.
In d'Urville's narrative it is stated under date of January 29 that at 4 p. m. he sighted one of the ships of the American Expedition (the Porpoise) and he "hoped that she intended to speak us." Through a misunderstanding of the maneuvering of the French flag-ship, Ringgold thought d'Urville wished to avoid a meeting, and although but "a cable's length distant" from the ship, he put his helm up and stood off to the southward.
Ringgold states that at 4 p. m., January 30, he sighted two ships which afterward proved to be the French vessels. He approached them "within musket shot" when to his surprise he saw them making sail, whereupon he hauled down his colors and stood off before the wind.
The discrepancy in dates was not noticed in reading the narratives but, wishing to see just where the meeting of the ships took place, their tracks were plotted on the same chart, when it appeared that the noon positions (d'Urville's January 29, and Ringgold's January 30) were near each other, and that the tracks crossed in the afternoon.
The discrepancy in dates seems to be remarkable, since both expeditions had crossed the i8oth meridian from east to west some months before and had sailed for the Antarctic, one from Hobart Town, Tasmania, and the other from Sydney, Australia, where the dates must have been identical.
We find in Wilkes' narrative, volume 2, page 159, this statement: "On crossing the meridian 18o° we dropped the 14th of November, in order to make our time correspond to that of the Eastern Hemisphere, to which our operations were for some months to be confined."
That d'Urville made no change of date in crossing the 180th meridian but maintained the same chronology appears from d'Urville's narrative, "Routes des Corvettes," volume 1, page 134, where, under date of October 13, 1838, the longitude is given as 1790 31' West, and on page 136 under date of October 14, 1838, it is given as 178° 53' East. He therefore made no change of date in crossing the i8oth meridian, as otherwise the second date would have been October 15 instead of October 14.
Further investigation of d'Urville's daily positions shows that every day is accounted for until June 22, 1840, which appears in volume I, page 340. On page 342 appears the date of June 24 with an asterisk, and at the bottom of the page is this note:
"Nous reprenons la date d'Europe,"
so that the date he dropped was June 23, 1840, five months after the visit to the Antarctic, and more than 20 months since he crossed the 180th meridian.
This means that in d'Urville's narrative of his discoveries and on the chart of his Antarctic voyage every noon position must have its date advanced one day in any comparison to be made with the noon positions and the discoveries of Wilkes' ships.
Wilkes believed that he sighted the Antarctic Continent on January 16, 1840, at about 158° East longitude. On January 19, however, he states that "land was now certainly visible from the Vincennes both to the south-south-east and south-west, in the former direction most distinctly. Both appeared high," etc.
D'Urville says in volume 8 of his narrative, under date of January 19 (which should be January 2o to correspond to Wilkes' time), "At 9 a. m. we saw in the E. S. E. a great black cloud which seemed stationary and had the appearance of a raised island." "Toward 3 p. m., M. Gervaize, who was officer of the watch, thought he saw once more an indication of land in the east." "At 10.50 p. m., this luminary (the sun) disappeared and showed up the raised contour of the land in all its sharpness." This land on January 21 (true date 22) he named Adelie Land.
Returning now to the meeting of the Porpoise and the French vessels: On the day following the meeting d'Urville reports: "At 6 o'clock the man on lookout had sighted the ice pack to the south and I brought the ship to the wind in order to go nearer to explore it; at to o'clock we were not more than three or four miles distant. It appeared prodigious. We saw a cliff with a uniform height of too to 150 feet, forming a long line westwards," etc.
It will be noticed that at 6 o'clock the ice pack and not the barrier was sighted.
Wilkes' narrative of the movements of the Porpoise for this day states: "The beginning of the 31st the gale continued; at 7 a. m. moderating, they again made sail to the westward; in half an hour discovered a high barrier of ice to the northward with ice islands to the southward; at to a. m. they found themselves in a great inlet formed of vast fields of ice which they had entered 12 hours previously; the only opening appearing to the eastward, they were compelled to retrace their steps, which was effected by 8 p. m." "They now found themselves out of this dangerous position, and passing the point, kept away to the westward."
"February 1.—The immense perpendicular barrier encountered yesterday was now in sight, trending as far as the eye could reach to the westward," etc.
The Porpoise, therefore, at 7.30 a. m., January 31, was in the entrance of the great inlet on the southeast side of d'Urville's "Cote Clarie" and had sighted the high barrier of ice, the northern side of which d'Urville reached about 10 o'clock the same forenoon.
It is established from this investigation that, even if Wilkes' sighting the Antarctic Continent on January 16 is not admitted, it is certain that he did sight Cape Hudson a day before d'Urville sighted Adelie Land and that Cote Clarie was sighted by the Porpoise on the same day that it was seen by d'Urville, but at an earlier hour.
Wilkes cruised along the coast of this continent for more than 1600 miles from his first landfall. Future exploration may, and indeed probably will, find that much of the land discovered by him was placed too near the barrier, or in other words too far north, for it is well known that distance estimated by the eye is liable to great error, and particularly is this the case in the polar regions.
Whether this proves to be so or not, this investigation establishes Wilkes' priority over d'Urville. The English sealer Balleny, in 1839, got a glimpse of land in about 1210 East, but all he says regarding it is, "Saw land to the southward." Neither d'Urville nor Balleny had any notion or made any suggestion that they were on the edge of a continent. Wilkes, on the contrary, not only sighted at frequent intervals some 1600 miles of this coast but he recognized that it must be part of a continent. The name he gave to this land, the Antarctic Continent, must belong to the entire continent the existence of which he revealed. Some geographers have recognized that the part of Antarctica he discovered needed a special name and therefore gave it the name of Wilkes Land. When it is remembered that Wilkes changed the conception that the Antarctic was an ocean, by demonstrating that it was a continent, the least that his discoveries demand is that the name of Wilkes Land be retained on all of Antarctica lying between the longitudes of 95° and 158° East.