The position of the southern magnetic pole has not yet been ascertained to so great a degree of precision. Excited by a noble spirit of emulation caused by the success of the expedition fitted out by Mr Booth and led by Sir John Ross, three expeditions have been fitted out to complete the solution of the problem--to fix the position of the southern magnetic pole, as that of the northern had been already fixed. The parties in this noble rivalry are Great Britain, France, and the United States. The British magnetic expedition, under Captain James Ross, sailed on the 5th of May for Van Diemen’s Land. The only notices as yet received of its progress are, that soundings were obtained at the depth of 3600 fathoms in the South Atlantic, about 900 miles S.S.W. of St Helena; and again at the depth of 2680 fathoms, at 450 miles west of the Cape of Good Hope. A dispatch from Captain Dumont d’Urville, commandant of the French expedition, to the Minister of the Marine, details all the leading particulars of his voyage, by which it appears that he has nearly though not altogether succeeded in solving this part of the problem. On the 1st of January the expedition sailed from Hobart Town in a southern direction for 1350 miles, and in the latitude of 60 degrees south met with the first island of ice, and shortly afterwards discovered land ranging nearly along the south polar circle, and, as far as the navigator’s observations went, between 136 degrees and 142 degrees east longitude. The appearance was that of an ice-bound, barren coast, wholly unfit for the habitation of man. The snow and ice which covered it gave its surface an almost level appearance. Farther inward nothing was to be perceived but ravines, inlets, and projections, without a trace of vegetation. Whales, large porpoises, fur-seals, albatrosses, and petrels and penguins of different species, were seen near the shore. The commander gave this newly discovered coast the name of Terre Adelie. “This name,” he says in his dispatch, “was intended to perpetuate the remembrance of my profound gratitude for the devoted companion who has three times consented to a long and painful separation, to enable me to achieve my projects of foreign exploration.” On the 1st of February, in 65 degrees 20 minutes south latitude, and 131 degrees east longitude, the expedition crossed the meridian of no variation; and the magnetic observations afforded the means of determining that the position of the magnetic pole must be in the neighbouring land of Adelie itself, or on the compact ice which adjoined it. Having so far succeeded in attaining the main object of his mission, Captain Dumont bade a final adieu to these dreary regions, and steered for Hobart Town, where he arrived on the 17th of February, after an absence of forty-six days, having lost sight of the ice altogether in the parallel of 57 degrees south latitude.