636 



NA TURE 



[May 20, 1922 



frame vanish on account of the invariance. Equations 

 so derived are mathematical identities which cannot be 

 controverted. 



(2) The vanishing of the variation for all small 

 changes of the parameters is a possible form for a law 

 of nature. Equations so derived rest on a particular 

 hypothesis which challenges criticism. 



We wish that the author had kept the results of 

 these two applications distinct. We believe that most 

 of the ascertained laws of physics are derivable by the 

 first application, and the second is responsible for some 

 additional results which cannot be tested and do not 

 appear to us particularly probable. 



The translator of such a book as this has our sincere 

 S5mipathy. He has done a useful work which yet falls 

 far short of complete success. There are many passages 

 in the original which we have turned to again and again, 

 and only very slowly grasped their meaning ; others 

 still defeat us. It was not to be expected that the 

 translator would penetrate the thought behind them, 

 and he has evidently given up the attempt to make 

 his rendering convey any possible sense. We would 

 not recommend any one to make a profound study of 

 this work without having the German original at hand 

 to consult when a difficulty is encountered. There are 

 other mistakes harder to excuse. Weyl's treatment of 

 space turns on the two conceptions of affine and 

 metrical geometry, and it is impossible to proceed 

 without mastering these. But the exposition of affine 

 geometry on p. 18 refers continually to postulates I 

 and II, and the reader will search in vain for any 

 postulates so indicated. In the German edition a mis- 

 print of I for I is comparatively harmless ; but in the 

 English edition the further substitution of 2 for II 

 extinguishes the reader's last hope of discovering what 

 the argument refers to. On pp. 141-2, two axioms 

 are printed as though they were headlines of the 

 paragraphs following. Absurd mistranslations such as 

 " mass of the earth " for " mass of the world " on 

 p. 296 will probably not do much harm, though they 

 shake our confidence. All the same, there is much 

 good work in the translation, and those who are 

 struggling to master Weyl's indispensable treatise will 

 welcome the partial aid which it affords. A. S. E. 



New Methods of Arctic Exploration. 



The Friendly Arctic : The Story of Five Years in Polar 

 Regions. By Vilhjahmar Stefansson. Pp. xxxi + 

 784 + plates. (London: Macmillan and Co., Ltd., 

 1 92 1.) 305. net. 



NO such original and assertive explorer of the 

 Arctic regions as Mr. Stefansson has appeared 

 since Dr. Nansen startled the admirals by dispensing 

 NO. 2742, VOL. 109] 



with a line of retreat. Mr. Stefansson's views are 

 however, far more upsetting than those of Dr. Nansen, 

 for he denies practically every theory and many reputed 

 facts regarding the North Polar area, and contemns 

 almost all the long-established methods of Arctic 

 travel. 



We cannot go on to Mr. Stefansson's vindication of 

 his own powers as a pioneer without first deprecating 

 his contemptuous tone with regard to arm-chair geo- 

 graphers and their views. Those harmless drudges do 

 their best to follow the published narratives of explorers 

 and to reconcile the contradictions between successive 

 travellers' reports. If they say in their compilations 

 that the Arctic Sea in its farther recesses is devoid of 

 life it is because explorers have told them so, and if 

 they dwell upon the hardships and dangers of Arctic 

 explorations it is because earlierand less expert explorers 

 did suffer and perish in the attempt to do, amid diffi- 

 culty and pain, what proves easy and pleasant to 

 Mr. Stefansson. We gladly acknowledge that Mr. 

 Stefansson treats Peary as a great and successful 

 explorer, and does full justice to McClintock's mar- 

 vellous sledge journeys on the Frankhn search ; but 

 he would have thought so much more of them if they 

 had seen how easy it was to " live off the country " ! 



In pp. 30-32 much is made of the assumed ignorance 

 on the part of Sir John Murray that sea-ice after long 

 exposure on the surface of a floe can yield drinkable 

 water. It seems to us that Sir John Murray probably 

 controverted Mr. Stefansson's statement on this point 

 not from ignorance but merely in order to test his 

 character, for it was a common thing with Murray to 

 see if a young man who knew something could be shaken 

 in his confidence as to his own knowledge by the weight 

 of an older man's authority. If Mr. Stefansson had 

 wavered, as we are very sure he did not, Sir John 

 Murray would have thought the less of him. As 

 a matter of fact, we know that Murray was greatly 

 impressed by the young Canadian's knowledge and 

 fitness. With this book before them we are sure that 

 the works of oceanographers and arm-chair geographers 

 will henceforth be purged of some errors and fortified 

 by many new facts ; but the whole load of learning left 

 by the old heroes of the North will not, on that account, 

 be thrown into the sea like Stefansson's despised canned 

 goods. 



In 1913 the Canadian Government took over and 

 financed an Arctic expedition which Mr. Stefansson 

 had been organising in co-operation with the National 

 Geographic Society of Washington and the American 

 Museum of Natural History. These institutions with- 

 drew their claims and so Stefansson's third Arctic 

 expedition was purely Canadian. A great programme 

 was prepared for work in two divisions, a northern in a 



