452 



N'ATURE 



[February 2, 191 1 



years followed by a wet year, which prevailed for England 

 and Wales for twenty-one years, including 1909, has now 

 completely broken down, and that it seems possible that 

 the swing of the pendulum is carrying us into a period of 

 predominating wet years, corresponding to the wet period 

 of 1874-83. 



In the Memorie del R. Istituto Lomhardo di Scienze e 

 Letterc Signor A. M. Pizzagalli has published a memoir, 

 "La cosmogonia di Bhrgu," an investigation of the rela- 

 tion of the rosmogonic myth to the epics of India. The 

 cosmogony of Bhrgu is part of one of the subdivisions of 

 the twelfth book of the Mahabharata ; it is in the form 

 of a dialogue between two legendary persons, Baradvaja 

 and Bhrgu, the former asking questions, the latter answer- 

 ing them. It deals with the origin of all things in the 

 animal as well as in the vegetable world, which are sup- 

 posed to have the same composition and to be essentially 

 identical. It shows how the vital flame combines with 

 the earth-element to form the body of the individual, while 

 the soul, an efflux of the Supreme Being, pervades and 

 rules the body and endows it with various qualities. A 

 complete translation of the dialogue is given ; there is 

 nothing astronomical in it. 



" The Structural Design of Aeroplanes " forms the 

 title of a paper' read before the Institution of Civil 

 Engineers of Ireland by Prof. Herbert Chatley about a 

 twelvemonth ago, and now reprinted (Dublin : John 

 Falconer, 1910). In it the author endeavours to apply 

 exact mathematical methods to the calculation of the 

 stresses in the sustaining framework of an aeroplane, as 

 well as in the supporting surfaces. In view of the 

 number of deaths that have resulted in the past year from 

 breakages of aeroplanes, the alternative causes frequently 

 being instability, it ought to be evident that the only way 

 of placing the problem of aviation on a satisfactory basis, 

 and of preventing future fatalities, is by encouraging the 

 further development of investigations such as Prof. 

 Chatley 's, and by determining exeprimentally the un- 

 known data which such investigations show to be neces- 

 sary in order to complete the solutions of such problems— 

 the latter being evidently a comparatively easy task. In 

 the discussion on the paper, however, we notice the usual 

 want of appreciation of the methods of exact science on 

 . the part of so-called " practical men." 



M. Gilbert Maire contributes to La Revue des I dees 

 for November 15, 1910, an account of an interesting 

 medico-psychological study of Prof. Henri Poincar^ under- 

 taken by Dr. Toulouse. " Owing to the wide public interest 

 which has been aroused, especially in France, by 

 Poincar^'s writings on the philosophy of science and on 

 the concepts of mathematics, many readers will wonder 

 how and under what conditions Poincar^ originates his 

 investigations. It is evident from the present account that 

 when absorbed in a problem Poincar6 has often, like many 

 another genius, become oblivious to matters of everyday 

 life. What seems, however, to have most impressed Dr. 

 Toulouse was that Poincar^'s discoveries were not arrived 

 at as the result of a concentration of mental effort, but 

 that they have come on him spontaneously, often when 

 his thoughts have been turned in quite different directions. 

 For this kind of faculty Dr. Toulouse has proposed the 

 name "auto conduction." Whether a new name was 

 really needed, or whether the same faculty has already 

 been recognised and described under other names, is a 

 matter on which there may be more than one opinion. 

 At the same time, the fact that Poincar^, and probably 

 many ether philosophers, and especially mathematicians, 

 NO. 2153, VOL. 85] 



became suddenly inspired by new ideas (and, indeed, find 

 it impossible to throw these ideas on one side, even 

 temporarily, until they have developed them), affords an 

 interesting problem for the psychologist, and Dr. 

 Toulouse's examination may well direct attention to this 

 problem. 



The four numbers of the Journal of the Royal Society 

 of Arts ending with that of January 13 contain the text of 

 the Cantor lectures on industrial pyrometry which hav^' 

 been delivered before the Society by Mr. C. R. Darling. 

 The last two lectures concern themselves mainly with tho 

 simplified forms of the platinum thermometer, the thermo- 

 junction, and the radiation pyrometer, which have been 

 constructed for use in works where observational skill on 

 the part of the users cannot be taken for granted. Several 

 of the methods described have received attention in these 

 columns as they have been developed from those suitable 

 for more accurate work. 



More than forty pages of the number of Hitnmel und 

 Erde for December 30, 1910, are devoted to addresses on 

 the principle of relativity which have been delivered before 

 scientific societies in Germany during the past year. Th<- 

 first of these, delivered by Prof. E. Cohn, of Strassburg, 

 before the Scientific and Medical Society of that city, aim 

 at a clear exposition of the principle to an audience 1 

 whom it was comparatively unknown, and it succeed - 

 admirably in its object by the help of experiments per- 

 formed with an ingenious model designed for the purpose. 

 The second, delivered by Prof. H. Poincar^, of Paris, 

 j before the Scientific Society of Berlin, goes somewhat 

 more fully into the reasons which have led to the extension 

 I to general physics of a principle as old as Galileo and 

 ! Newton, that our knowledge of the motion of any body 

 can only be of its motion with respect to some other body. 

 When this principle is traced to its logical conclusion in 

 relation to the known facts about the speed of light, it 

 leads to the denial of most of the laws of the old 

 mechanics. The units of mass, length, and time on one 

 moving body will differ from those on another moving 

 body by amounts which depend on the relative motions of 

 i the bodies with respect to each other. Prof. Poincar6 is 

 not disposed to accept the principle as fundamental 

 throughout physics, and points out many of the difficulties 

 which still have to be overcome before it can be regarded 

 as altogether satisfactory. 



W'E have just had the opportunity of trying the " tab- 

 loid " preparations of Messrs. Burroughs Wellcome and 

 Co. as specially arranged for colour photography by the 

 single-plate (or screen-plate) processes. They give excel- 

 lent results, and the uniformity which the use of tabloids 

 ensures eliminates a fruitful source of uncertainty that too 

 often spoils the work of those who use such plates at 

 irregular intervals. The formulae given are suitable for 

 the Autochrome, Thames, Ominicolore, and Dufay plates. 

 The cartons are three only— the developer, the reversing 

 compound, and the intensifier, the last often being un- 

 necessary. 



A paper on the inversion of cane-sugar under the 

 influence of acids and neutral salts, by Mr. Noel Deerr, 

 has been issued as Bulletin No. 35 of the Agricultural and 

 Chemical Series of the Experiment Station of the Hawanan 

 Sugar Planters' Association. The author has determmed 

 the influence of twenty-three different salts upon the rate 

 of inversion of cane-sugar by hydrochloric and other acids. 



The Bio-Chemical Journal of January 17 contains an 

 article, by Prof. B. Moore, " In Memory of Sidney Ringer 



