October i i, 1906] 



NA TURE 



60- 



\'cnturcrs at an outlay of about 50,000/., which is covered 

 by insurance, but not the least heavy loss sustained is 

 that of books and manuscripts in the library of ihe 

 principal, Prof. W'ertheimer. 



At Ihe dislribulion of prizes awarded to successful 

 students of the Royal College of Science, for the session 

 1905-6, on October 4, Prof. \V. A. Tilden, who presided, 

 remarked that two public events of "Jreat imporlance to 

 the college have occurred since the prize distribution last 

 year. The first is the publication of the final report of 

 the departmental eoniniittee appointed to study the con- 

 dition, appliances, purposes, and xvork of the Royal College 

 of Science and the Royal School of Mines, and to consider 

 what could best be dom- with them. The eoniniittee well 

 described the main object of the institution to be the teach- 

 ing of science, especially in its application to industry. 

 The other event is the practical completion of the great 

 museum buildings, which have been in progress for seven 

 or eight years. Dr. T. E. Thorpe, who presented the 

 prizes, in an address to the students said those whose 

 business it is to examine students recognised that the 

 system of examinations, like all human institutions, is 

 liable to fall into error. Nevertheless, it is the conviction 

 of those who ha\"e given dispassionate consideration to the 

 matter that, faulty and fallible as the system may be, it 

 affords the best method of arriving at the relative positions 

 of schools and students. As a rule, in England a uni- 

 versity takes only its name from the place in which it is 

 situated. What has made the .Aberdeen I'niversity an 

 integral part of the life of the people is that the people 

 make special efforts to create and maintain it, and their 

 self-sacrifice on its behalf gives them an abiding interest 

 in it. It is an unfortunate thing for education in I-ondon 

 that London is so vast it is impossible to get collective 

 effort and collective influence enlisted for any of its educa- 

 tional institutions. 



A SERIES of articles on public-school education was com- 

 menced in the Times of September 10, and among the 

 subjects which have been dealt with in the eight contribu- 

 tions which have been published already are mathematics, 

 science, and engineering. Mr. T. J. Garstang, in his 

 article on the teaching of mathematics (September 13), 

 traces the course of development which has led to the 

 adoption of reformed courses of geometry, arithmetic, and 

 algebra in our schools. Much, however, remains still to 

 be accomplished. .\s Mr. darstang points out, the com- 

 mercial arithmetic still exacted through examinations is 

 largely either a survival of past commercial method or a 

 collection of artificial fictions. Mr. W. D. Eggar, writing 

 on science in public schools (September 20), considers what 

 school science is now compared with what it was thirty 

 years ago. Thanks largely to Prof. Armstrong's efforts, 

 science teaching by lectures or talks illustrated by curious 

 experiments has given place to practical work, by which 

 pupils measure and weigh and accumulate experience by and 

 for themselves. If nature-study forms part of the English 

 leaching in schools, and practical measurement part of the 

 mathematical work. Mr. Eggar thinks it is possible in one 

 stage of every boy's career to give him a real chance of 

 learning scientific method. In some middle portion of the 

 school through which all boys must pass, a year's course 

 with four hours a week should be mapped out. To this 

 work the main energies of the laboratory staff must be 

 directed, and the classes must be small. The most suitable 

 subjects Mr. Eggar believes to be heat or chemistry or 

 magnetism and current electricity. The subject should be 

 one in which mathematical theory may be kept in the 

 b.ickground until a thorough prautical acquaintance with 

 facts has been gained ; also one which gives ample scope 

 for cultivating the scientific virtues of accuracy and 

 honesty. The Rev. F. .Stephenson describes (October q) 

 what is done by a public school to train bovs who intend 

 to become engineers. In his concluding paragraph he 

 remarks: — "The public school caters mostly for those 

 whose means and brains alike are limited, and attenipts to 

 combine the teaching of the science of engineering in the 

 class-room with practice in the workshops in such .1 way 

 that at eighteen a bov mav be readv to take full advantage 

 of the opportunities offered him in large commercial works, 



NO. 1928, vol. 74] 



and may neither waste six months in picking up as best 

 he mav from mechanics the purport of nuts, valves, and 

 cylinders, nor allow himself to sink in manners and morals 

 to lower standards that may not unnaturally be prevalent 

 among associates of a humbler class." 



SOCIETII'S AM) ACADEMIES. 



LONDO.X. 



Royal Society, June 28.— "An Investigation of the 



Influence of Electric Eields on .Spectral Lines." Pre- 

 liminary Note. By Prof. C. E. Hull. Communicated by 

 Prof. J. Larmor, Sec.R.S. 



In general the electrical fields used were those con- 

 comitant with the luminous electric discharge. An inter- 

 ferometer of the .Michelson form and an echelon spectro- 

 scope of eighteen plates were used to analyse the radi- 

 ations. The results may be summarised as follows : — 



(i) End-on discharge tubes of special design in which 

 the light-source was a uniform column of luminous mercury 

 vapour, viewed in the direction of discharge, showed no 

 change of wave-length so great as i part in 4,000,000 when 

 the direction of the discharge was reversed. The pressure 

 in the tube was varied from a few millimetres to a vacuum 

 sojiigh that there was but little luminosity. 



(2) The passage of Rcintgen rays through the tube did 

 not alter the wave-length nor the width of the mercury 

 lines to an extent sufficient to affect the visibility of inter- 

 ference fringes formed with a difference of path of 400,000 

 waves. When the luminous column was viewed at right 

 angles to the direction of the discharge no polarisation 

 effects in the radiation from it, due to the passage of the 

 Rontgen rays, could be detected by a sensitive Savart plate 

 and Nicol prism. 



(3) When the discharge passed in air between electrodes 

 foriTied of an amalgam of cadmium and mercury, no vari- 

 ation of the wave-lengths of the strong Cd, Hg, lines 

 greater than 0002 tenth-metre w-as obtained by changing 

 the line of sight from a direction along the discharge to 

 one at right angles to that direction. .Approximately the 

 same result held good when a small capacity was inserted 

 in the circuit, but in this case the discrepancies in the 

 readings were larger. 



This result shows that the luminous particles do not 

 acquire a velocity in the direction of the discharge greater 

 than 150 metres per second. Hence the curving of the 

 image of the discharge produced by a rotating mirror, as 

 in the Feddersen experiment, and as recently studied by 

 Schuster and Hemsalech for individual spectral lines, 

 appears to be due, not so much to motion of luminous 

 particles as to the propagation along those particles of a 

 condition of luminosity. 



(4) Doppler effects in the canal rays, as announced by 

 Stark during the course of the present investigations, were 

 found for the strong hydrogen lines. In some cases they 

 appeared also in mercury lines. The velocities represented 

 bv the displacements of the lines were of the order of 

 4 X 10" metres per second for the hydrogen particles and 

 2-5x10' metres per second for those of mercury. But it 

 was found that, in general, the luminous mercury particles 

 in the canal ravs did not move (with a velocity greater 

 than 100 metres per second). In these cases the canal rays 

 appear to be due to non-luminous particles streaming 

 through the mercury vapour and producing luminescence 

 in the latter, probably by bombardment. 



(5) A glass tube was sealed on to a canal-ray lube at 

 right angles to the direction of the rays. This tube was 

 covered bv a piece of optical glass as free as possible from 

 strain. .\ verv sensitive combination of Savart plate and 

 Nicol prism w'as used to detect, if possible, any polarisa- 

 tion that might exist in the light from the rays in hydrogen. 

 .\fter eliminating reflections from the walls of the lube no 

 polarisation could be recognised. 



(6) The light produced by electrical discharge, in uniform 

 tubes 3 cm. or 4 cm. in diameter, was examined at right 

 angles' to the direction of discharge, at various points 

 between the electrodes, and also behind the perforated 

 kathode. It was found that the principal hydrogen lines 

 „.ere greatlv broadened in tho^e parts where the electric 



