Miscellaneous Intelligence. 319 



Similar formations have been observed by Nansen and Payer, 

 and the presumption is that the soft strata represent snow fallen 

 during winter, and the hard a surface partially melted during the 

 warmer months and re-frozen. Under great pressure the whole 

 mass is gradually converted into homogeneous hard blue ice. 



Concerning the several motions of the inland ice, we are with- 

 out information of any kind. Of the various computations as to 

 its mean thickness, Dr. Fricker adopts that of Thomson — 1400 

 feet. 



According to Heim, there are four possible agencies tending 

 toward the dissolution of glacier ice — melting from above, melt- 

 ing from below, internal melting, and the breaking away of drift 

 ice. From the considerations stated above it appears that Ant- 

 arctic glaciers are chiefly exposed to the second and last of these, 

 the action of warm water eating away the under surface, and the 

 separation of enormous icebergs. Under the most moderate esti- 

 mates, Dr. Fricker calculates Uiat a minimum of 258,000,000,000 

 cubic metres of ice are annually detached from the ice barrier 

 and set adrift. The subsequent wanderings of these bergs are 

 chiefly controlled by the ocean currents, although the direct 

 influence of wind is considerable ; and the normal " northern limit 

 of drift-ice " is of special interest from the amount of informa- 

 tion relating to currents Avhich can — due caution being exercised 

 — be obtained from it. Taken generally, the set of the currents 

 corresponds in direction to the prevailing winds, from south 

 toward north, northwest and west. To this rule there are, 

 however, important exceptions. A comparatively strong easterly 

 current prevails to the south of Cape Horn, probably because of 

 the strong development of west-wind drift to high latitudes in 

 the South Pacific, and the contraction of Bransfield Strait. 

 Again, the motion of the streams becomes extremely involved in 

 the two cases where the coast trends north and south, east of 

 Gerritsz Land and Victoria Land, in part probably simple tidal, 

 and in part " compensation currents" flowing southward. Neu- 

 mayer to the contrary notwithstanding, Dr. Fricker admits the 

 existence of only one true southerly current — to the south of 

 Kerguelen — and of this he proposes an extremely ingenious ex- 

 planation. Kerguelen and Head Island are connected by a range 

 of submarine mountains some 240 miles in length, which rises to 

 within 100 fathoms of the surface. Assuming that the westerly 

 drift current extends below this depth, on meeting the obstacle 

 it will divide and a part will be deflected in a south-southeasterly 

 direction, and will to some extent retain that direction by virtue 

 of its superiority in speed over the currents of higher latitudes. 

 The other section of the current, deflected northward, may ac- 

 count for the bend of isothermal lines in that direction observed 

 in the vicinity of Kerguelen. 



The general northward tendency of the surface currents, taken 

 along with the known presence of Antarctic water in the lower 

 depths of the oceans of the southern hemisphere, raises a ques- 



