THE RENEWAL OF ANTARCTIC EXPLORATION. 361 



Glimcoriite is auotlier niiueral which w;is procured in the blue iniids 

 near Antarctic laud. This mineral tills the shells of foraminifera and 

 other calcareoiis organisms, and has been found in the muds along 

 nearly all continental shores where the debris of continental rocks makes 

 up the greater }>art of the deposit. Glauconite is now in process of 

 formation in all these positions, but it is apparently wholly absent from 

 the pelagic deposits of the great ocean basins far from continental land, 

 as well as from the deposits around volcanic islands. Its i)reseiice in 

 the blue muds of the far south is therefore most suggestive of an Antarc- 

 tic continent. 



When we come to estimate the extent of this sixth continental area, 

 greater difficulties are presented. A knowledge of the depths of the 

 surrounding ocean would enable the outlines to be drawn with great 

 exactitude, but unfortunately the positions where accurate soundings 

 have been taken are few and lar between. In the South Pacific, South 

 Atlantic, and South Indian oceans, between the latitudes of 30° and 

 50° south, we have most excellent lines of soundings right round the 

 world and in these latitudes the average dejith of the ocean is over 

 2,300 fathoms, or about 2i miles.* Between the latitudes of 50° and 

 Gjo south, the indications we possess appear to show a gradual shoal- 

 ing, with an average depth of about 1,700 fathoms, or nearly 2 miles. 

 1 have been criticised for showing on bathymetrical charts a great depth 

 in the Southern Ocean to the southwest of south Georgia. This has been 

 done because of a sounding by Iloss, who paid out 4,000 fathoms of line 

 at this spot without linding bottom. Eoss knew perfectly well how to 

 take deep-sea soundings, and his observation seems to show that the 

 ocean is" here deeper than 4,000 fathoms, and this may well be accepted 

 till dis})roved by more trustworthy results; besides the temperature of 

 the deep water to the east of South America points t<> a. great depth in 

 this region. The depths obtained by the ChaUenger in tln^ luMghbor- 

 hood of the Antarcti(; Circle were l,(»7o, 1,800, and 1,300 fathoms, and 

 judging from the nature of the deposits 1 think all these were within 

 100 or 200 miles from land. Wilkes obtained depths of oOO and 800 

 fathoms about 20 or 30 miles from the shore of Adelie Land, and Ross 

 obtained many soundings of from 100 to 500 fathoms all over a great bank 

 extending 200 miles to the east of Victoria Land; similar depths have 

 been found to extend to some distance to the east of Joinville Land to 

 the south of Cape Horn. We have no trustworthy indications of ridges, 

 barriers, or banks extending far northwards from Antarctica. It is, 

 therefore, most probable that the northern continents are everywhere 

 cut off from the Antarctic land mass by a depth approaching to, if not 

 exceeding, 2 miles. Taking all these indications into consideration I 

 have shown on the map what 1 believe to be the probable i)osition and 

 extent of Antarctica. Like other continents it would appear to have 

 mountain ranges with volcanoes facing one ocean, and lower hills and 



See accompanyiug luaj) of South Pol.ir Jiiea. 



