April 3, 19 19] 



NATURE 



97 



to the work of the teacher and social worker respec- 

 rively. All communications should be addressed to the 

 Secretary, Summer School of Civics and Eugenics 

 I Lincoln's Inn Fields, London, W.C.2. ' 



There are about to be submitted to the Senate of 

 I he University of London, in the interests of de- 

 mobilised officers and men, of released war-workers 

 and other persons, proposal? for starting next session 

 within the University a special two years' course of 

 comprehensive study for intending journalists, and for 

 instituting a University diploma in journalism to be 

 awarded after examination to students taking the 

 special course. The proposals have been drafted by 

 committee formed of leading members of the Uni- 

 rsity of London under the chairmanship of Sir 

 Mdney Lee, Dean of the faculty of arts, in conference 

 with the chief officers of the Institute of Journalists 

 and representatives of the Appointments Department 

 of the Ministry of Labour and of the Board of Educa- 

 tion. Persons interested in the matter are invited to 

 communicate, by letter only, with Sir Sidnev Lee at 

 the University of London, South Kensington, S.W.7, 

 -ind to place the words "Courses for Journalists" on 

 'le outside of the envelope. 



SOCIETIES AND ACADEMIES. 

 London. 



Royal Society, March 20.— Sir J. J. Thomson, presi- 

 dent, in the chair.— Dr. C. Chree : Magnetic 

 storms of March 7-8 and August 15-16, 1918, and 

 their discussion. The storms were of the same general 

 type as one which occurred on December 16-17, 19 17, 

 and was discussed in a previous paper ; but, unlike the 

 previous storm, they both had conspicuous S.C.'s 

 (■•sudden commencements"). The movements con- 

 stituting the S.C. on August 15-ib were unusually 

 large, and their oscillatory character was verv pro- 

 minent at Agincourt and Eskdalemuir. In both' cases, , 

 as in the storm of December, 19 17, disturbance was \ 

 much larger at Eskdalemuir than at Kew, especially j 

 in the vertical force. The declination changes at the I 

 two places showed rather a close resemblance, but the I 

 variations in the other elements differed at times not I 

 int-rely in amplitude, but also in general character. The | 

 disturbance at Agincourt on March 7-8 was similar , 

 in intensity to that at Eskdalemuir, but conspicuously 

 different in many details. There were some exceed- I 

 ingly large and rapid changes, especially of declina- I 

 tion and horizontal force, at Agincourt, the range of 

 the former element being about 2° 5', as compared 

 with 51' at Kew.— L. C. Martin: The transparency of 

 biotite to infra-red radiations. The paper describes a 

 curious reversible variation with temperature in the 

 infra-red transmission of biotite. Tables and curves 

 showing the variation in transmission of biotite with 

 wave-length at various temperatures are given, and 



tain possible explanations are examined. , The 



iieral nature of the effect is a halving of the trans- 

 mission for a rise in temperature of about 200° C. 



March 27. — Sir J. J. Thomson, president, in the 

 chair.— H. L. Hawkins : The morphology and evolu- 

 tion of the ambulacrum in the Echinoidea. — Dr. R. 

 Mc Garrison : The genesis of oedema in beri-beri. 



Physical Society, February 28.— Prof. C. H. Lees, 

 president, in the chair.— P. R. Coursey : Simplified 

 inductance calculations, with special reference to thick 

 coils. The method of calculation advocated in the 

 paper is based on an extension of Nagaoka's formula 

 for single-layer coils, to include as well all ordinary I 

 forms of thick coils. Rosa's formula for thick coils I 

 is put into the same form as Nagaoka's, and its use | 

 enables a series of correction factors to be calculated I 



NO. 2579, VOL. 103] 



for various coil thicknesses. By the aid of a single 

 sheet of curves giving values of these correction 

 factors the inductance of anv form of coil likely to 

 be met with in practice may be readily calculated, 

 using only one simple standard formula for all cases. 

 —Dr. R. Dunstan : Acoustic experiments in connection 

 with whistles and flutes. Experiments were made 

 with hollow spheres, cylinders, and cones with holes 

 of various sizes and in various positions. Bernoulli's 

 j theorem, which gives the wave-length of the sound 

 produced by a cylindrical pipe in terms of the length 

 of the pipe and an end-correction depending on the 

 diameter only, was shown to be inadequate for prac- 

 tical purposes, the pitch depending on many other 

 factors, such as the wind-pressure, the size and shape 

 ! of the blow-hole, etc. Cylindrical flutes appear to 

 require an end-correction which — within certain limits 

 —-is' equal to D'/d, where D is the diameter of the 

 pipe and d the mean diameter of the mouth-hole 

 (which is often oval in shape). In the shortest flute 

 experimented with, which was only i in. long, Ber- 

 noulli's theorem would give the wave-length as 2 in., 

 whereas it was actually 14 in. The conclusions drawn 

 from ^ the experiments are that in blowing across a 

 hole in a hollow body a force existed on an elastic 

 substance. The result is a ''spring hack" which 

 produces an aerial throb, puff, or pulsation. The 

 frequency of the pulsation is determined by relations 

 between the dimensions of the instrument, the size 

 of the hole, the wind-pressure, etc. Any resulting 

 sound has its wave-length determined by the frequency, 

 and not primarily by the dimensions of the instru- 

 ment, as in the usual text-book treatment.— G. 

 Brodsky : A new polariser. In the course of experi- 

 ments with polarisers built of piles of glass plates 

 disadvantages due to bulkiness of the apparatus and 

 loss of light had to be overcome. The idea occurred 

 to the author to place the pile of plates between two 

 prisms of the same glass in such a manner as to 

 (a) reduce the length of the polariser by one-half; 

 (h) utilise the full aperture of the pile; and (c) get 

 rid of all reflected light. Results obtained with experi- 

 mental prisms were so good that thev could be con- 

 sidered a very fair substitute for Nicol prisms of 

 corresponding size, and the very small amount of 

 light escaping through crossed prisms (which could bo 

 reduced further by additional plates) is for most pur- 

 poses negligible. There would be no difficulty in 

 building such polarisers to any required size, as all 

 the material consisted entirely of glass in unlimited 

 quantities and at a reasonable price, and it was hoped 

 that this invention (British patent No. 121,906) would 

 be used for manv purposes. Experiments with piles 

 of glass plates showed a very large discrepancy be- 

 tween the calculated and observed angle for best ex- 

 tinction. Whatever the glass used, and whatever the 

 quality of the surface, this discrepancy came con- 

 sistently to some 10°. whereas thin microscope-cover 

 plates were found to be useless. There seemed to be 

 still an interesting field for investigation as to the 

 conditions affecting the surface of glass plates used 

 ill polarisers. 



Aristotelian Society, March 17.— Dr. G. E. Moore, 

 president, in the chair. — A. E. Heath : The scope of 

 the scientific method. Though the man of science makes 

 a conscious effort to avoid anthropocentric bias in his 

 treatment of any field, this does not mean that he 

 is confined to non-human fields. Ethical neutrality 

 of method does not imply limitation to an ethically 

 neutral subject-matter. Consequently it is held that 

 the scientific met ho<l can be applied to any domain of 

 experience.' This thesis is supported by: — (r) The 

 claim that what is attempted is always the complete 

 description, by both qualitative and quantitative for- 



