6io 



NA TURE 



[April 25, 1901 



Wm. Shackleton, of the Solar Physics Laboratory, physic- 

 ist and astronomer ; Dr. E. A. Wilson, zoologist and 

 -doctor to the land party ; and the writer, who is director 

 •of the civilian staff and in command of the operations 

 on shore. It is hoped that it may be possible to arrange 

 ^for additional scientific assistance from volunteers who 

 will accompany the ship in her cruises from Melbourne. 

 Mr. G. Murray, F.R.S., who is editing the "Antarctic 

 Manual," has kindly consented to act as deputy director 

 of the civilian staff, and will superintend the scientific 

 equipment in England, and probably accompany the 

 Discovery as far as Melbourne. 



Terrestrial Magnetism. 



Considerations for the magnetic work have exercised a 

 dominant influence in the plan of operations ordered by 

 the Joint Committee. Magnetic work in the British 

 field of operations has difficulties from which work in 

 the western half of the Antarctic area is free ; the hori- 

 zontal magnetic force is exceptionally low, and great 

 decimal variations in declination are frequent. These 

 variations will, of course, affect the observations made 

 on the Discovery, and unless this factor can be allowed 

 for, it will be impossible to determine the proper mag- 

 netic elements for the ship's points of observation. 

 Accordingly, the Magnetic Committee has declared it 

 •essential that there should be a station on shore in 

 Southern Victoria Land to act as secondary magnetic 

 base. It will be the first duty of the party landed at this 

 station to secure a continuous magnetic record for a 

 period of twelve months. For that purpose it will be 

 supplied with a magnetograph, which will be under the 

 special care of Mr. Shackleton ; should the recording 

 instrument fail, personal observations must be taken as 

 frequently as possible. The records at this station will 

 enable the observations taken during the magnetic survey 

 at sea to be corrected for diurnal changes. 



The Joint Committee has, therefore, decided that the 

 Discovery shall proceed from her southern headquarters 

 at Melbourne to Southern Victoria Land, where Captain 

 Scott will land a party somewhere between McMurdo 

 Bay and Wood Bay. The land party will consist of 

 -eight men, including Mr. Shackleton as physicist and 

 Dr. E. A. Wilson as doctor and zoologist. 



The Geographical Problems. 



The selection of Southern Victoria Land, and the 

 neighbourhood of Mounts Erebus and Terror, for the 

 tiite of the land station is recommended by geographical 

 as well as by magnetic considerations. Topographical ex- 

 ploration is the second important branch of the work of 

 the expedition, for it is necessary as a base for much of 

 the other work ; and it was probably interest in this 

 subject that inspired Colonel Longstaff's munificent 

 donation, which brought the expedition within the range 

 of practical politics. 



Fortunately, sufficient is now known of the geography of 

 the eastern half of the Antarctic area to enable a definite 

 plan of operations to be arranged. We need not, like 

 ■Cook, strike blindly into the Antarctic, knowing no more 

 of one line than of another. There are two main geo- 

 graphical problems in the British field of work. The first 

 problem is whether the known lands to the south of Aus- 

 tralia — Victoria Land, Wilkes Land, Adelie Land, Geikie 

 Land, Newnes Land, Termination Land, &c. — are all part 

 of one great continent or are members of an Antarctic 

 archipelago. The classical and mediaeval geographers 

 accepted the existence of an Antarctic continent, belief 

 in which is now supported by Suess's principles of 

 geographical distribution. 



Australia, as Suess has explained to us, consists of a 

 great plateau bounded to the north and east by the im- 

 portant tectonic line which passes through New Guinea, 

 ■ New Caledonia and New Zealand. Ritter has therefore 



NO. 1643, VOL. 63] 



very plausibly suggested that the volcanic chain that 

 forms the eastern face of Victoria Land is the continua- 

 tion of the New Zealand volcanic line, and that the 

 coast of Wilkes Land is a southern extension of the 

 Australian plateau. 



This hypothesis, advanced at first on general con- 

 siderations, is consistent with all available geological 

 evidence. The specimens collected by Wilkes and the 

 boulders dredged by the Challenger and' the Valdivia 

 include archaean and sedimentary rocks similar to those 

 of Southern Australia ; 'and Mr. Borchgrevink has 

 brought home a collection of specimens which have 

 been kindly shown to me by Mr. Prior, and are prac- 

 tically identical with some of the Lower Palasozoic rocks 

 of Victoria. 



The rocks of the eastern face of Victoria Land have 

 been described by Teall and David ; and their identi- 

 fications show that the volcanic rocks resemble those of 

 New Zealand.^ 



There is, thei'efore, little doubt that Antarctica is geo- 

 logically a continent, consisting of a western plateau, 

 composed of archaean and sedimentary rocks like those 

 of Australia, and of an eastern volcanic chain. But 

 whether Antarctica is still a continent geographically is 

 less certain ; and this question can only be conclusively 

 settled by a survey. Land journeys westward and south- 

 ward from Mount Erebus ought to settle this problem. 



The volcanic line of Victoria Land runs north and 

 south for some 8 or lo degrees of latitude ; at T]° S. lat. 

 the coast and the volcanic chain bends abruptly to the 

 east. The discovery of their eastward continuation is 

 the second main geographical problem to be settled in 

 the British half of the Antarctic area. 



Ross sailed to the east for some 30 degrees, along the 

 face of the " Ice-Barrier" ; and though the origin of the 

 barrier-ice is not yet certainly known, it has probably been 

 formed on land. Ross has recorded a " strong appear- 

 ance of land " beyond the eastern end of the barrier 

 (160° W.), and the barrier may be roughly parallel to the 

 edge of a land line connecting the Parry Mountains 

 and Ross's " apparent land." 



Beyond this pomt is a gap until, 70° further to the 

 east, we come to Graham's Land. In the intermediate 

 area there has been no direct record of any large land 

 area that would connect Graham's Land and Victoria 

 Land. But Cook's description of his view from his 

 turning-point at 137° W. 67° S. is suggestive of a land 

 with peaks rising through an ice-sheet rather than of a 

 number of icebergs frozen into pack-ice. Cook, how- 

 ever, clearly interpreted it as the latter. The indirect 

 evidence as to the geographical character of the line 

 between Graham's Land and Mounts Erebus and Terror 

 is more important. It is based on Suess's law of coast 

 distribution. 



The Pacific Ocean is bounded by coasts the trend of 

 which is determined by mountain ranges which run 

 parallel to the shore. This rule holds in Eastern Aus- 

 tralia, Eastern Asia, Malaysia, and throughout the 

 western coast of America with an unimportant exception 

 in Central America. The remaining coasts of the world 

 are on the Atlantic type, in which the coast lines 

 are not determined by the trend of long, folded moun- 

 tain chains ; the mountain ranges are cut transversely 

 or obliquely, and the coasts are mainly formed of 

 plateaux and coast plains. Ritter has made the pro- 

 bable suggestion that the low coast of Wilkes Land is 

 on the Atlantic type, and the high mountain chain of 

 Victoria Land is on the Pacific type. Graham's Land 

 has a characteristic Pacific coast ; and when we remem- 

 ber the persistence of that type round the whole of the 



1 The continuation of the tectonic line that crosses Southern New Zea- 

 land obliquely to the main New Zealand line has not yet been determined, 

 and it may be found to play an important part in the southern shore of the 

 Pacific. I 



