The materials brought by the expedition are numerous in all their branches, but their study will not be completed before two or three years. It will not be until then that we can ascertain the importance of the results obtained. Thanks to the Belgian Government, a great publication is expected, and a commission has been chosen to organise and direct it.
We can, nevertheless, and immediately, enumerate some of the results. This is what I propose to do in a few words with this reservation: that these indications are, for the most part, provisional and far from representing a complete table of the scientific advantages which will be derived from the expedition.
GEOGRAPHY AND GEOLOGY
THE geographical discoveries were made in the south and west of Bransfield Strait in Dirk-Gerritz Archipelago. In this region earlier explorers noticed a large land (Palmerland), separated by a gulf (Hughes Gulf) from another land situated in the east (Trinityland). Larsen, the captain of the Jason (1892), having seen south of Louis Philippeland a vast communication between the Atlantic and the Pacific, Trinityland became an island for geographers. Dallmann, the captain of the Grönland (1872), had discovered on the Pacific side an entrance to a strait (Bismarck Strait). Geographers then made an effort, upon the maps, to communicate Hughes Gulf with Bismarck Strait.
The observations of the Belgian Antarctic Expedition demonstrate that this is all incorrect. Palmerland is a vast archipelago of small islands; Hughes Gulf is the entrance to a large strait which brings Bransfield Strait into communication with the Pacific Ocean. This strait extends from latitude 63° 51′ to 65° south, and its direction is north-east to south-west. The Pacific mouth of Belgica Strait does not coincide with the entrance to Bismarck Strait, which, from the position assigned by Dallmann, is situated much farther south; but it is possible that Dallmann made a mistake in his observation, and that this is the very same strait. Trinityland is but the cape-land of a large tract (Dancoland) which forms the eastern shore of Belgica Strait, and which is only the continuation of Grahamland.
The shores of Belgica Channel are formed by high, mountainous table-lands with steep slopes and narrow valleys. One of the peaks appears to rise above an altitude of two thousand metres. The channels which separate these lands have steep perpendicular shores and possess great depths in their centre. The appearance of these lands and channels indicates that we have to do with a sunken region, in which the valleys were invaded by the sea. These lands are entirely formed by ancient crystalline rocks, granites, greenstones, and syenites. We have seen gneiss only at the mouth of the Pacific Strait. This fact indicates that we were in the central part of the antarctic chain, whose general direction is that of Belgica Strait. At the time of our sojourn in these regions, from the 23d of January to the 12th of February, the strait was free from ice. There were only a few icebergs. If some small islands were only partially covered with ice, all those of a larger extent and Dancoland were completely covered with an immense crust of ice which showed itself under three different forms. The interior was all occupied by a frozen sheet, which may be compared with the Greenland inland ice. Everywhere upon the mountain-sides were suspended glaciers, and in all the valleys were tremendous crystalline currents which ran into the sea. The limit of eternal snow coincides here almost to a certainty with the level of the sea. The study of the moraines allowed us to state that the glaciers had receded, and at the same time gave us a decisive information as to a much more considerable extension at an anterior epoch. The erratic materials furnish us with rocks much more varied than those found on the spot. We have even met with transformed sedimentary rocks.
Another important geographical discovery is that of a continental table-land or plateau situated between longitude 75° and 103° west of Greenwich, and from latitude 70° to 71° 36′ south. Its mean depth is 500 metres; with an abrupt fall to 1500 metres towards the north. The depth of the continental plateau, generally placed at from 200 to 300 metres, shows that this region has also undergone the depressive movement which was remarked in the lands of Belgica Strait. The continental plateau rises gently towards the south, and lowers in its eastern portion towards the north in order to connect itself most assuredly with the continental plateau of Graham and Alexander lands. It must connect in a like manner towards the west, fifty degrees farther, with the continental plateau discovered by Ross east of Victorialand. We would then have a continuous or uninterrupted continental mass from longitude 50° west to 63° east. However, the discovery made by the Belgica gives a serious support to the hypothesis of an antarctic continent—an hypothesis made the more likely from many other considerations, of which I shall cite only one, which is in its place here; that is to say, the terreous nature of the sediments of the continental plateau and neighbouring regions. Indeed, these sediments contain, besides the grayish slime, a very strong proportion of sand, gravel, and a very great number of pebbles of rounded form, which were certainly rolled by the sea, and were a part of a littoral cordon. I need not say that the transport of these substances must have been made by the ice. If this plateau indicates the existence of a continental mass south of the seventy-second parallel, inversely, the driftway of the Belgica demonstrates the non-existence of the ice-wall reported by Bellingshausen, and the same thing may be said of the land signalled by Walker, since we passed with the ice-drift over its supposed position. The easy drifting of the pack towards the west renders impossible the presence of the land reported by Cook towards longitude 105° west.
ASTRONOMY AND MAGNETISM
The magnetic observations were the object of mensuration upon the deflection, inclination, and terrestrial magnetic intensity. They were effected principally with the aid of the Neumayer apparatus; Gambey’s compass and Brunner’s theodolite were utilised on land, either at the stopping-places on Belgica Channel or in the known regions, where they were used for comparing and determining constant quantities. On the ice-pack the perpetual motions of the ice did not allow us to install our apparatus for variations. Absolute and ready measurements were the only ones made. The magnetic stations number sixty.
The astronomical observations had for their principal object chronometric regulations. We utilised the method of lunar distances—that of star occultations by the moon, as well as the eclipses of Jupiter’s satellites.