DISCOVERY 



293 



This book naturally appeared originally in German, 

 and it is leirgely due to the enthusiasm of the trans- 

 lator. Dr. Lawson, that the book now appears in 

 English in its present fonn. Dr. Lawson was doing 

 research on radium in Vienna prior to hostihties, and 

 unfortunately was compelled to remain there during 

 the war, and therefore to miss a good deal of the fun 

 and excitement and food which was the happy lot of 

 most of us elsewhere. But he learned German, and 

 this clear and excellent translation is a testimony to 

 his knowledge of that language. He has got Professor 

 Einstein to add an appendLx on the experimental con- 

 firmation of the general theory,' and he has prefaced 

 the volume with a crayon drawing of the author by 

 a German artist, which we reproduce here. 

 « * * * * 



It would be madness for me to attempt to say any- 

 thing about relativity itself in a few paragraphs except 

 just to indicate in broadest outline the general plan 

 of the book. The book begins by explaining clearly 

 the principle of relati\'ity, and why it is necessary to 

 accept it. The author then goes on to show that on 

 the old principles of mechanics the law of propagation 

 of light and the principle of relativity are incompatible, 

 and, as there seems to be no clear way out if either is 

 given up, a dilemma arises. The special theory of 

 relativity, which does away completely with this 

 dilemma, is then stated and explained by several 

 carefully chosen illustrations, and the hitherto tacit 

 assumption that the statement of time has an absolute 

 significance, i.e. that it is independent of the state of 

 motion of the body of reference, is shown to be incom- 

 patible with the most elerrientary facts. Next the 

 general theory of relativity (of which the special theory 

 is merely a special case) is introduced and explained, 

 and the amazing result arrived at that, in general, 

 rays of light are propagated curvilinearly in gravita- 

 tional fields. Considerations on the universe as a 

 whole arising out of the general theory — the possi- 

 bility of a finite yet unbounded universe, and the 

 general structure of space — perhaps the most inter- 

 esting part of all, conclude the book. 



***** 



A correspondent who is interested in my remarks 

 on " dowsing " last month sends me his experiences. 

 For some time he has acted as sponsor for a man who 

 lives in the same town, who is a thoroughly good 

 dowser. He is quite convinced that this peculiar 

 power is genuine, and is inchned to think it is probably 

 in some way electrical in origin. A real, thorough, 

 scientific investigation of the whole business in a 

 laboratory has not yet been done. Various tests, how- 

 ever, of different kinds and degrees of difficulty have 

 been set the dowser, and metals have been graded as 

 ' See Discovery, February 1920, p. 48. 



good, bad, and indifierent, according to the amount 

 of " pull " experienced by him at a distance of three feet. 

 It was found that the dowser is sensitive to gold, 

 silver, copper, and zinc, but not to brass, to platinum, 

 or to steel. He is particularly sensitive to nickel. 

 My correspondent further points out that water- 

 dowsing from the scientific point of view is a by-path, 

 for there the phenomenon is studied under con- 

 ditions needlessly difficult. What is primarily needed 

 is an investigator to collaborate with the dowser in 

 carrying out a series of experiments under definite 

 laboratory conditions, so that methods and apparatus 

 for measuring the amount and distance of the stimulus 

 and the amount of the response can be worked out as 

 a preliminary to a thorough investigation in detail. 

 ***** 

 I have since met this dowser myself, and he did 

 several very interesting experiments for me. He is 

 most sensitive to running water (he is not at all sensi- 

 tive to stagnant water), then to nickel, gold, silver, 

 and copper in decreasing order. He is sensitive also 

 to certain alloys ; to bronze, for instance, but not to 

 brass. He can tell quite easily whether you have 

 concealed under a hat a sensitive object like a shilling, 

 or something to which he is insensitive, hke a piece of 

 brass or a brick. One of his stunts is to say whether 

 or not water is running through the water-pipe at a 

 certain place, and this he can do easily, and appar- 

 ently infalhbly. He can tell whether your safe has 

 any valuables (in metal) in it, and he has succeeded 

 in locating hidden safes by his response to the gold 

 and silver inside of them. He finds, however, that 

 he cannot detect things which are placed above him, 

 and also that the presence of a second sensitive sub- 

 stance at a few feet in a certain direction to another 

 sensitive object inhibits the effect. Apart altogether 

 from the scientific explanation of dowsing, and from 

 its utihty in locating underground springs, a demon- 

 stration of dowsing makes a first-class parlour enter- 

 tainment. 



Was Drake Guilty of 

 Murder ? 



By GeoflFrey Gallender 



Head 0/ the History DepuTimenl , R.S. CoUcrje, Osborne 



" A VERY reUgious man towards God and His houses, 

 generally sparing the churches wherever he came ; 

 chaste in his hfe, just in his dealings, true of his word, 

 and merciftd to those that were under him." Such 

 is the character of Francis Drake drawn by Fuller 



