404 



NATURE 



[May 



A coMfUMENTARV banquet to Prof. H. E. Armstrong, 

 F.R.S., tookplace ot the Hotel Cecil on Saturday, May 13. 

 Although intended, in the first instance, to take the form 

 of a demonstration of affectionate regard on the part of hit 

 old students, it was soon found necessary to extend the 

 scope of the celebration, which thus became tho occasion 

 for one of the largest scientific gatherings of recent years. 

 The toast of the guest of the evening was proposed by the 

 chairman, Prof. W. J. Pope, F.R.S., and was seconded 

 by Mr. Maurice Solomon. The guests included Sir William 

 Crookes, Sir James Dewar, Sir Chas. Lawcs, Profs. H. B. 

 Baker, A. Brown, Clowes, Crossley, Divers, Henderson, 

 Kipping, and Wynne, Messrs. W. Barlow, G. T. Beilby, 

 H. T. Brown. Cross, Hall, R. Mcssel, R. L. Mond, F. B. 

 Power, and J. E. Stead amongst the chemists; engineer- 

 ing was represented by Profs. Perry, Dalby, Mather, and 

 Sumpner ; education by Principal Miers, Mr. R. Blair, Dr. 

 J. H. Cowham, Prof. R. A. Gregory, Mr. A. L. Soper, 

 and Mr. C. M. Stuart; law by Mr. W. Phipson Beale, 

 K.C. ; and literature by Prof. M. A. Gerothwohl. On two 

 occasions the Chemical Society has met in order to cele- 

 brate the jubilee of five of its past presidents, but we 

 believe that only one similar gathering has previously been 

 organised by a group of chemical students in honour of 

 their professor. The success of the enterprise was most 

 gratifying; "Central" students of every year, from the 

 date of the opening of the college to the present day, united 

 with chemists and others from all over the country, to the 

 number of 230, in honouring one whose influence has been 

 felt and valued by an exceptionally wide circle of admirers 

 and friends. 



The following regulations with reference to the newly 

 founded prize in memory of Lord Kelvin have just been 

 issued by the University of Glasgow : — (i) The prize shall 

 consist of a gold medal of the value of 10/., together with 

 the balance of the income of the capital fund accumulated 

 during three years. (2) The adjudicators shall be the prin- 

 cipal, the professor of natural philosophy, and the professor 

 of mathematics. (3) The prize shall be awarded by the 

 Senatus, on the recommendation of the adjudicators, at 

 intervals of three years (the first period beginning with 

 191 1) to the author of a thesis or published work in 

 natural philosophy, including therein mathematical and 

 experimental physics, which has been submitted and 

 approved for the degree of Doctor of Science during the 

 period, and which gives evidence of original research 

 worthy in the opinion of the adjudicators of this special 

 distinction. (4) In making their recommendation, the 

 adjudicators shall have regard to the written reports pre- 

 sented to the faculty of science by the examiners and 

 additional examiners appointed under Section X. of Uni- 

 versity Court Ordinance No. XXVI. (5) Not more than 

 one award shall be made in each period of three years, 

 and the prize shall not be divided. The adjudicators may. 

 if they think fit, recommend that for a particular period 

 of three years no award be made, and, in that case, the 

 income of the prize shall be added to the capital fund. 

 (6) The Kelvin prize and the William Jack prize shall not 

 be awarded to the same person. (7) After the year iq20 

 the regulations may from time to time be modified by the 

 Senatus. with the approval of the University Court, pro- 

 vided always that the prize shall continue to be awarded 

 to graduates of the University for special distinction in 

 original research relating to mathematical and experi- 

 mental physics. 



SOCIETIES AND ACADEMIES. 



London. 

 Royal Society, May li.— Sir Archibald Geikie, K.C.B. 

 president, in the chair.— C. T. R. Wilson : A method of 

 making visible the paths of ionising particles through a 

 gas. The paths are made visible by condensing water 

 upon the ions immediately after their liberation, an ex- 

 pansion apparatus being' used which works without 

 appreciable stirring up of the air. The trails of ions 

 formed by the a particles from radium have in this wav 

 been made visible and photographed, verv dense and 

 sharply defined rays of cloud being formed on expansion. 

 Air exposed to B rays gives clouds consisting mainly of 

 NO. 2168, VOL. 86] 



faint straight threads radiating from tne kource; these h;^' 

 not yet been photographed. Tn air exposed to y rays, tli- 

 cloud is again in the form of straight threads trnversi! .; 

 the cloud chamber — the tracks of P partick^ 

 The cloud formed in air exposed to K 

 ,>ri'-' !■ • ' nrcntrated in minute streaks uiivj , 

 j>i shows these to consist mainly of 



11" ig a few mm. in length, and genera .ji 



straight, probably the tracks of kathode rays produced in 

 the air by the X-rays. The whole of the ionisation would 

 appear, as Bragg has already suggested, to be effected by 

 the kathode rays derived from the X-rays. — W. H. Din*« : 

 The vertical temperature distribution in the atmosphere 

 over England, and some remarks on the general and local 

 circulation. This paper gives an account of the results of 

 some 200 observations made in the British Isles in the 

 years 1908, 1909, and 19 10 on the temperature of the upper 

 air. It discusses the annual variation of the temperature 

 up to 14 kilometres, and shows that the annual range 

 remains fairly steady, with a total amp"' ' / • 

 12° C. up to II km., above which the ran:^ 



to 3°, and the times of the maxima and ; ^^ 



two months. The question of the daily variation at great 

 heights is then discussed. The relation between the 

 temperature at various heights and the height of the baro- 

 meter at the surface is dealt with, and it is shown how 

 over a low-pressure area with the barometer below 740 mm. 

 the temperature of the first 8 km. is very low, reaching 

 at 7 km. a value of nearly 10° C. below its average value, 

 and that above 10 km. it is considerably above the averag--. 

 In the anti-cyclonic parts the conditions are reversed, an'f 

 it is warm below and cold above. The height at which 

 the isothermal region is met with in summer and wint- r 

 and in times of high and low barometer is then referred to. 

 A statement with regard to the existence of similar con- 

 ditions that have been found to exist on the Continent i^ 

 also given. In the second part of the paper various 

 theoretical considerations are taken into account. It is 

 shown that if an extensive and strong wind exists in any 

 part of the atmosphere, warm air will be found somewhat 

 below it on its right hand, and cold air above it on th" 

 right, with converse conditions on the left, and it is pointed 

 out that this agrees with the distribution of temperature 

 that is found to exist at the various levels of cyclones and 

 anticyclones. — Prof. W. N. Hartley : Some mineral con- 

 stituents of a dusty atmosphere. — Dr. H. Stanley Allen : 

 The path of an electron in combined radial magnetic anct 

 electric fields. The path of an electron in a radial electric 

 field superposed on a radial magnetic field is found to li'* 

 on a circular cone the vertex of which coincides with 

 the magnetic pole. If the surface of the cone is develop^-fJ 

 into a plane, the trace of the path is a conic section with 

 The vertex as focus. The solution in the particular cas» 

 in which there is no electric field has been given by 

 Poincar6 ; the path is then a geodesic line on the surface 

 of the cone, and, of course, becomes a straight line when 

 the cone is developed. In cases which can be realised 

 experimentally, the developed path is hyperbolic, and does 

 not in general differ greatly from a straight line. An 

 account is given of some experiments carried out to illu- 

 trate the theory. The first observations were made with .1 

 focus tube in which the antikathode was the pole of an 

 electromagnet. The phenomena observed are easily ex- 

 plained in terms of the theory. Other vacuum tubes were 

 prepared in which a fine pencil of kathode rays could be 

 produced by means of a Wehnelt kathode. In a radial 

 magnetic field the stream of electrons assumed a spiral 

 form, and a number of photographs were obtained show- 

 ing the spiral paths on a cone of revolution. — Dr. R. A. 

 Houstoun : The absolute measurement of light — a pro- 

 posal for an ultimate light standard. .\ thermopile cannot 

 be used for the measurement of candle^>ower. because it 

 gives the same value to the energy of every wave-length, 

 invisible as well as visible. The author has. however, 

 found by spectrophotometric investigation in the ultra- 

 violet, visible, and infra-red parts of the spectrum that if 

 a filter consisting of aqueous solutions of copper sulphate 

 and potassium bichromate in a particular strength in glass 

 cells be placed before the thermopile, then this filter stops 

 the ultra-violet and infra-red entirely, and lets through a 

 fraction of each wave-length in the visible spectrum pro- 



