December 3, 1908] 



N-A TURE 



135 



Electrical Conference, had reached a full age ; but 

 Becquerel was in the full tide of life, and we had hoped 

 to learn much more from him. As the discoverer of radio- 

 activity, he had opened up inquiries the significance of 

 which seems ever on the increase. Science has lost a 

 leader ; his friends and the world a charming personality. 



During the time that I was secretary, and so concerned 

 with the passing of mathematical papers through the 

 press, 1 was much struck with the carelessness of authors 

 in the arrangement of their manuscript. It is frequently 

 forgotten that a line of print in the Transactions and in 

 the new form of the Proceedings will hold much more 

 than a line of ordinary manuscript, unless, indeed, the 

 handwriting is exceptionally small. Unless the authors' 

 indications were supplemented, it frequently occurred that 

 several lines of print were occupied by what might equally 

 well, and in my judgment much better, be contained in 

 one line. Even practised writers would do well, when they 

 regard their manuscript as complete so far as regards 

 matter and phrasing, to go over it again entirely from the 

 point of view of the printing. In this way much expense 

 and space would be spared, and the appearance of the 

 printed page improved. 



Apart from questions of printing, the choice of symbols 

 for representing mathematical and physical quantities is 

 of some importance, and is embarrassed by varying usages, 

 especially in different countries. A committee now sitting 

 is concerned with the selection of symbols for electrical 

 and magnetic quantities, but the question is really much 

 wider. One hesitates to suggest another international 

 conference, and perhaps something could be done by dis- 

 cussion in scientific newspapers. Obviously some give and 

 lake woufd be necessary. When the arguments from con- 

 venience are about balanced, appeal might be made to the 

 authoritv of distinguished men, especially of those who 

 were pioneers in the definition and use of the quantity to 

 be represented. As an example of the difificulties to be 

 faced, I may instance the important case of a symbol for 

 refractive index. In Knglish writings the symbol is usually 

 /i, and on the Continent n. By the early optical writers 

 it would seem that no particular symbol was appropriated, 

 in 1815 (Phil. Trans., 1815) Brewster has m. The earliest 

 use of II that I have come across is by Sir John Herschel 

 (I'hil. Trans., 1821, p. 230), and the same symbol was 

 used by Coddington (1829) and by Hamilton (1830), both 

 distinguished workers in optics. On the other hand, n 

 was employed by Fraunhofer (1S15), and his authority must 

 lie reckoned very high. As regards convenience, I should 

 -.oppose that the balance of advantage would incline to /i, 

 since n is wanted so frequently in other senses. Another 

 case in which there may be difficulties in obtaining a 

 much-to-be-desired uniformity is- the symbol for electrical 

 resistance. 



On a former occasion 1 indulged in comment upon the 

 tendency of some recent mathematics, which were doubt- 

 less understood as the mild grumbling of an elderly man 

 who does not like to see himself left too far behind. In 

 the same spirit 1 am inclined to complain of what seem 

 unnecessary changes in mathematical nomenclature. In 

 my youth, by a natural extension of a long-established 

 usage relative to equations, we spoke of the yools of a 

 function, meaning thereby those values of the argument 

 which cause the junction to vanish. In many modern 

 writings I read of the zeroes of a function in the same 

 sense. There may be reasons for this change ; but the 

 new expression seems to need precaution in its use, other- 

 wise we are led to such flow-ers of speech as " zeroes with 

 real part positive," which I recently came across (Proc. 

 Math. Soc, vol. xxxi., p. 266). But though I may use 

 a little my privilege of grumbling over details, I hope I 

 shall not be misunderstood as undervaluing the progress 

 made in recent years, which, indeed, seems to me to be 

 very remarkable and satisfactory, regarded from the scien- 

 tific point of view. On the other hand, I cannot help 

 feeling misgivings as to the suitability of the highly 

 specialised mathematics of the present day for a genera! 

 intellectual training, and I hope that a careful watch may 

 be maintained to check, in good time, any evil tendencies 

 that may become apparent. 



.^mong the notable advances of the present vear is the 

 liquefaction of helium by Prof. Onnes, of Levden. It is 



NO. 2040, VOL. 79] 



but a few years since Sir J. Dewar opened up a new field 

 of temperature by his liquefaction of hydrogen, and now a 

 further extension is made which, if reckoned merely in 

 difference of temperature, may appear inconsiderable, but 

 seen from the proper thermodynamical standpoint is recog- 

 nised to be far-reaching. The exploration of this new field 

 can hardly fail to afford valuable guidance for our ideas 

 concerning the general properties and constitution of matter. 

 Prof. Onnes *s success is the reward of labours well directed 

 and protracted over many years. 



The discovery and application by Rutherford and Geiger 

 of an electrical method of counting the number of a par- 

 ticles from radio-active substances constitutes an important 

 step, and one that appears to afford better determinations 

 than hitherto of various fundamental quantities. It would 

 be of interest to learn what interpretation is put upon 

 these results by those who still desire to regard matter as 

 homogeneous. 



Another very interesting observation published during 

 the year is that of Hale upon the Zeeman effect in sun- 

 spots, tending to show that the spots are fields of intense 

 magnetic force. Anything which promises a clue as to the 

 nature of these mysterious peculiarities of the solar surface 

 is especially welcome. Until we understand better than 

 we do these solar processes, on which our very existence 

 depends, we may do well to cultivate a humbler frame of 

 mind than that indulged in by some of our colleagues. 



A theoretical question of importance is raised by the 

 observations of Nordniann and Tikhoff showing a small 

 chromatic displacement of the phase of minimum bright- 

 ness in the case of certain variable stars. The absence of 

 such an effect has been hitherto the principal argument 

 on the experimental side for assuming a velocity of pro- 

 pagation in vacuum independent of frcquencv or wave- 

 length. The tendency of the observations would be to 

 suggest a dispersion in the same direction as in ordinary 

 matter, but of almost infinitesimal amount, in view of the 

 immense distances over which the propagation takes place. 

 Lebedew has pointed out that this conclusion may be 

 evaded by assuming an asymmetry involving colour in the 

 process by which the variability is brought about, and he 

 remarks that although the dispersions indicated by Nord- 

 mann and Tikhoff are in the same direction, the amounts 

 calculated from the best available values of the parallaxes 

 differ in the ratio of 30 to i. In view of this discrepancy 

 and of the extreme minuteness of the dispersion that would 

 be indicated, the probabilities seem at the moment to lie 

 on the side of Lebedew's explanation ; doubtless further 

 facts will be available in the near future. 



I cannot abstain from including in the achievements of 

 the year the remarkable successes in mechanical flight 

 attained by the brothers Wright, although the interest is 

 rather social and practical than purely scientific. For 

 many years, in fact ever since I became acquainted with 

 the work of Penaud and Wenham, I have leaned to the 

 opinion that flight was possible as a jeai. This question 

 is now settled, and the tendency may perhaps be to jump 

 too quickly to the conclusion that what can be done as a 

 feat will soon be possible for the purposes of daily life. 

 But there is a very large gap to be bridged over : and the 

 argument urged by Prof. Newcomb, and based on the prin- 

 ciple of dynamical similarity, that the difficulties must 

 increase with the scale of the machines, goes far to pre- 

 clude the idea that regular ocean service will be con- 

 ducted by flying machines rather than by ships ; but, as 

 ihe history of science and invention abundantly proves, it 

 is rash to set limits. For special purposes, such as ex- 

 ploration, we may expect to see flying machines in use 

 before many years have passed. 



The report of the National Physical Laboratory for the 

 year again indicates remarkable growth. The various new 

 buildings, which have been erected and equipped during 

 recent years at a cost of about 33,000/., are now occupied, 

 and the result is that both researches and test work can 

 be carried out with much greater ease and efficiency than 

 previously. The buildings of the magnetic observatory at 

 Eskdalemuir are now occupied, but, unfortunately, difficulty 

 has arisen in making the magnetograph rooms, which are 

 underground, completely water-tight, and the recording 

 apparatus is not yet properly installed. 



The progress of the " Royal Society Catalogue of Scien- 



