-March 30, 19 16] 



NATURE 



103 



THE SHACKLETON ANTARCTIC 

 EXPEDITION. 



THE news that arrived at the end of last week 

 from the Shackleton Antarctic Expedition 

 Avas of an unexpected nature. The Aurora, dur- 

 ing" a severe gale, broke loose from her mooring^s 

 €arly in May, 191 5, and drifted in the pack ice, 

 suffering severe damag^e, until March 14, 1916, 

 -when she g'Ot free in 64° 30' S. 161° E., and is 

 riow on her way to Xew Zealand. When the 

 Aurora broke adrift, a number of officers and men 

 were ashore, including- Captain Macintosh, and 

 were unable to rejoin the ship. The wireless tele- 

 grams received seem to indicate that ten men 

 are thus left stranded at the Ross Sea base near 

 Cape Evans. They were probably engag^ed in 

 ■depot-lay ingf over the barrier in preparation for 

 the arrival of Sir Ernest Shackleton and his party 

 in their trans-continental march. 



News received during- the winter from South 

 'Georgia had already warned us that Sir Ernest 

 Shackleton had been unlucky in meeting with 

 an unfavourable season, and the weather in 

 Australia suggests that the exceptionally severe 

 conditions extend to the area of Antarctica south 

 ■of Australasia. The ice in the Weddell Sea is 

 known to be exceptionall}- variable in extent ; and 

 success in the exploration of that region will prob- 

 ably always be largely determined by the good or 

 ill fortune of the explorers in regard to the ice con- 

 ditions. An expedition which found the Weddell 

 Sea as Weddell found it could do more in one 

 season than in ten years under average conditions. 



The continued absence of news from the Endur- 

 ance — the ship which took the trans-continental 

 party to the Weddell Sea — is disappointing, as it 

 is thus still doubtful whether Sir Ernest Shackle- 

 ton has begun his daring trans- Antarctic sledge 

 journey, and whether a favourable base was estab- 

 lished on the shore of the Weddell Sea. But the 

 Endurance may well have delayed her voyage back 

 as late as possible on the chance of Shackleton 's 

 return to the western base, and to allow the \\'ed- 

 dell Sea parties to have- a full season's work. No 

 anxiety regarding the Endurance need be felt for 

 another fortnight, and news of her safe arrival 

 at the Falkland Islands may be received any day. 



The news from the Ross Sea demands more im- 

 mediate preparation; for though the latest dis- 

 patch from the Aurora shows that she is sea- 

 worthy, she is admittedly so badly strained that 

 it is possible that she may be too injured to be 

 trusted with the relief of the party left at Mac- 

 murdo Sound. The explorers left there should be 

 quite safe. They have two huts, both of which 

 appear to be sound. Half the heating arrange- 

 rnents of the Discovery hut were left behind in 

 New Zealand, and it was not lined with the insu- 

 lating material taken out to render it heat-proof. 

 But either hut would furnish safe shelter, and the 

 stores left at this base must be ample for the men 

 left ashore, and for Sir Ernest Shackleton and his 

 partv. Moreover, plenty* of penguins and seals 

 ^an be found. It is, however, clear that unless the 

 Aurora can be repaired In Australasia, another 

 NO. 2422, VOL. 97] 



ship must be sent out ; for a relief expedition must 

 go to the Ross Sea next season. 



The absence of news from the Endurance is 

 embarrassing, as it may be that another or even 

 two other relief expeditions may be required. If 

 the Endurance does not return within a fortnight, 

 arrangements will have to be made for the dis- 

 patch of a relief ship to the Weddell Sea. Prob- 

 ably one of the South Georgia whalers might be 

 sent on this mission; but as the South Atlantic 

 is so much nearer than the Ross Sea there would 

 be ample time to send out a suitable ship from 

 this countrj'. It must also be remembered that if 

 Sir Ernest Shackleton started on his daring 

 journey and has not reached either Macmurdo 

 So;und or returned to his Weddell Sea base, it 

 will be necessary to search for him ; for he may 

 have reached some place on the coast, where 

 he could live through the winter on seal and 

 penguin. No final decision can be made until time 

 has been allowed for the return of the Endurance . 

 but a full scheme of operations should be readv 

 for definite action shortly after the arrival of the 

 Aurora and the last day upon which we mav 

 reasonably expect this season the return of the 

 Endurance. 



RICHARD DEDEKIND. 

 'X*HE death of Dedekind deserves more than a 

 ■•- passing notice because he belonged to 

 that small class of profound and original mathe- 

 maticians typified by such men as Hermite, 

 Kronecker, and H. J. S. Smith. In at least four 

 great branches of pure mathematics he made 

 contributions of the highest importance, and, as 

 a tribute to his memory, a brief account of tl.em 

 will be given here. 



It is now becoming a matter of common know- 

 j ledge that the very foundations of all mathe- 

 ! matics have been reconstructed in such a way as 

 I to make the science like symbolical logic, and, 

 in theory, independent of all intuition whatever. 

 The beginning of this revolution was the acquire- 

 ment of a precise conception of irrational 

 numbers, and of the nature of the arithmetical 

 continuum. Dedekind shares with Heine, 

 Kronecker, and Cantor the glory of making this 

 theor}- complete. His own exposition is contained 

 in the two tracts, "Was sind u. was sollen die 

 Zahlen?" and " Ueber 'Stetigkeit u. irrationale 

 Zalilen," and in some ways is the simplest and 

 most philosophical of all that have been devised. 

 It may be remarked also that he did this novel 

 work without inventing more than one new 

 symbol. He also shares with Cantor the credit 

 of pointing out that, if we are to assume that 

 the uniform motion of a point along a segment 

 AB is an exact image of a real numerical variable 

 increasing from a to b, we must introduce an 

 axiom of some sort. This axiom, known as the 

 Cantor-Dedekind axiom, may be put into various 

 equivalent forms ; one of them is that any definite 

 segment of a straight line must be terminated by 

 two definite points. 



