November 9, 1905 J 



NATURE 



43 



Bruce puts it, " after more than sixty years of doubt, Ross 

 Deep was removed from the map, and all the bathy- 

 metrical maps based upon this sounding were no longer 

 •of any practical use. It is interesting to contrast the 

 methods of sounding employed on the two occasions by 



:e in 74 VS. off Coats Land. The shearlegs 

 bailed trap in 161 fathoms. 



comparing Mr. Bruce 's photographs, which we reproduce, 

 with the illustration given in Ross's book. Another dis- 

 covery of great importance is that of a ridge showing a 

 continuation of the " South Atlantic rise " a thousand 



through South Georgia to the Falkland Islands and South 

 American continent." . . . "Antarctica, South America, 

 and Madagascar, become connected with one another in a 

 most direct manner by this ' rise.' " Basing his arguments 

 on these discoveries, Mr. Bruce strongly opposes Sir 

 Clements Markham's theory, set 

 forth in his recent address to the 

 Royal Geographical Society, that the 

 Antarctic area consists of two land 

 ma^s,-, of unequal size, Victoria 

 Land and Edward VII. Land, separ- 

 ated by a great barrier of ice, and 

 of two seas extending far to the 

 south, the Ross Sea and the Weddell 

 Sea. 



The papers by Dr. Harvey Pirie 

 and Mr. Mossman contain many 

 points of great interest, although in 

 the nature of things the material 

 1 1 llei ted requires further elabor- 

 ation, and comparison with that of 

 the other expeditions, before its full 

 value becomes apparent. Dr. 



Harvey Pirie's observations give 

 much additional information bear- 

 ing on the variations in the relative 

 amounts of diatoms in the surface 

 waters and in the deposits, and the 

 remarkable differences in the meteor- 

 ological values for 1903 and 1904 

 enable Mr. Mossman to draw many 

 important conclusions as to the 

 factors controlling the climate. Mr. 

 Rudmose Brown gives an interesting 

 how the position of the account of an island which has, 



curiously enough, remained unex- 

 plored until now, although it lies 

 almost on the track of sailing-ships outward bound via 

 the ("ape of Good Hope. 



THE PERCY SLA DEN EXPEDITION IN 

 II. M.S. SEALARK. 



T HAVE just received the accompanying communi- 

 cation from Mr. Stanley Gardiner, bringing the 

 account of his expedition to September 12, the date 

 of his letter. The letter is written from Coetivev. 

 I may remind readers of Nature that his former 

 communications appeared in the issues of August 10 

 and October 5. A. Sedgwick. 



Zoological Laboratory, Cambridge, October 23. 



miles further south than it was previously known to exist. 

 There is thus a ridge " extending in a curve from Mada- 

 gascar^ Bouvet Island, and from Bouvet Island to the 

 Sandwich Group, whence there is a forked connection 

 through the South Orkneys to Graham's Land, and 



Since my last letter Cooper and I have had a tour 

 round the reefs of Mauritius, and have for the last 

 three weeks been working between the latter island 

 and the Seychelles Group. The Mauritius reefs vary 

 from fringing to barrier, the best example of the 

 latter being at Grand Port, where it is four miles 

 from the land. It has there a few small islets of 

 somewhat metamorphosed coral-rock, varying up to 

 40 feet high. At first it seemed as if they might 

 have been formed by hurricanes and blown sand, but 

 we discovered the same rock in the immediate 

 vicinity overlying a basalt, 70 feet above the water. 

 The present islets probably represent the remains of 

 a considerable island, elevated for at least 100 feet, 

 extending along that part of the barrier reef. 



Leaving Mauritius on August 21, we had three 

 days' dredging and sounding off its reefs. The con- 

 tour is the same as that off atoll-reefs, a gradual 

 slope to 40 fms. (fathoms), succeeded by a steep to 

 150 fms., then tailing off in five miles to 1000 fms. 

 The bottom at 150 fms. was covered by heavy blocks 

 of coral from the reef above. At 300 fms. we found 

 shell and small pieces of coral, and further out a 

 bottom of bare coral mud, sweepings from the reef and 

 land. 



no. ibfc'o, vol. 7$] 



