490 



NA TURE 



[September 14, 1905 



In the present article it is impossible to go further 

 into details. The apparatus as illustrated is rather 

 crude and elementary, but I think enough has been 

 said to justify the view that a good deal of useful 

 work might be done by working with apparatus on 

 these lines. W. R. Cooper. 



A 



THE INTERNATIONAL UNION FOR 

 COOPERATION IN SOLAR RESEARCH. 

 CONFERENCE of the International Union for 

 Cooperation in Solar Research will be held on 

 September 27 at New College, Oxford, by invitation 

 of the warden and fellows of the college. The 

 following delegates of societies constituting the 

 union have signified their intention of being 

 present ; — 



From the United States, Profs. Hale and Camp- 

 bell; from France, Messrs. Janssen, Deslandres, 

 Fabry, Perot, and the Comte de la Baume Pluvinel ; 

 from Russia. M. Belopolski ; from Germany, Prof. 

 H. Kayser; from Holland, Prof. H. H. Julius; from 

 .Sweden, Prof. Knut Angstrom; from Switzerland, 

 Prof. .\. W'olfer ; from .'Austria, as representative of 

 the International Association of Academies, Prof. 

 Edmund Weiss. Great Britain will be represented by 

 Profs. Turner, Schuster, and Fowler, Father Cortie, 

 Mr. W. E. Wilson, Major Hills, Dr. W. J. S. 

 Lockyer, and Dr. Halm. The subjects of discussion 

 will include the following : — 



The fixing of standards of wave-length in spectro- 

 scopic research, cooperation in the measurement of 

 the intensity of solar radiation, cooperation in record- 

 ing solar phenomena by means of photographs of the 

 disc, spectroheliograph records and observations at 

 the limb of the sun. 



The foreign savants will be lodged at and enter- 

 tained by New College. On Friday, September 29, 

 the president of the Astronomical Society and Mrs. 

 Maw will give a reception at their residence in 

 London, and for the following day invitations to visit 

 the observatories at Cambridge have been received 

 from Sir Robert Ball and Mr. Newall. Prof. 

 Schuster is acting as chairman of the executive com- 

 mittee which was appointed last year at the first 

 conference of the union held at St. Louis. 



NOTES. 



The meeting of the International Meteorological Con- 

 ference at Innsbruck was opened on Saturday last, 

 September 9, and the full sittings began on Monday. The 

 following is a list of members attending the conference : — 

 F. Ackerblom, Upsala ; Rev. P. J. Algu(5, S.J., Manila; 

 A. Angot, Paris ; R. Assmann, LIndenberg bei Breskow ; 

 A. Belar, Lalbach ; W. v. Bezold, Berlin ; B. Brunhes, 

 Puy de D6me ; V. Carlhelm-Gyllenskold, Stockholm ; 

 V. Conrad, Vienna ; P. M. Dechevrens, Jersey ; E. Durand- 

 Gr^vllle, Mentone ; Sir John Eliot, London ; F. Erk, 

 Munich; E. van Everdlngen, de Hilt; G. FIneman, 

 Stockholm; Rev. P. L. Froc, S.J., Zi-ka-wel ; V. 

 Gama, Tacubaya Obs., Mexico; G. Greim, Darm- 

 stadt; J. Hann, Vienna; G. Hellmann, Berlin; E. Hepltes, 

 Bukarest; H. Hergesell, Strassburg; H. H. Hilde- 

 brandsson, Upsala; W. Kesslltz, Pola ; N. v. Konkoly, 

 Budapest ; W. Koppen, Hamburg ; A. Lancaster, Uccle ; 

 W. LAska, Lemberg; E. Lauda, Vienna; J. Liznar, 

 Vienna ; Sir N. Lockyer, London ; W. J. S. Lockyer, 

 London; J. H. Lyons, Cairo; E. Mazelle, Triest ; 

 H. Mohn, Christiania ; A. Mohorovlcic, Agram ; L. Moore, 

 Washington; M. Nedelkovitch, Belgrade; L. Palazzo, 

 Rome; .\. Paulsen, Copenhagen; J. M. Pernter, \'lenna ; 

 NO 1872, VOL. 72] 



F. C. A. Pockels, Heidelberg ; P. Polls, .Aachen ; G. B. 

 Rizzo, Messina; A. L. Rotch, Boston; P. v. Rudzki, 

 Cracow ; M. Rykatchew, Petersburg ; .\. Schmidt, Pots- 

 dam ; A. Schmidt, Stuttgart ; P. Schreiber, Dresden ; Ch. 

 Schultheiss, Karlsruhe ; Rev. P. Th. Schwarz, Krems- 

 miinster ; W. N. Shaw, London ; .\. Silvado, Rio de 

 Janeiro ; R. F. Stupart, Toronto ; L. Telsserenc de Bort, 

 Trappes ; W. Trabert, Innsbruck; J. Valentin, Vienna; 

 J. VioUe, Paris. The members of the Solar Commission 

 are : — M. Angot, Sir John Eliot, Prof. Hann, Sir N. 

 Lockyer (president). Dr. Lockyer, Captain Lyons, Prof. 

 Pernter, Prof. Rlzzo, Dr. Rotch, Dr. Shaw, M. Telsserenc 

 de Bort, Dr. Konkoly. 



The Carnegie Institution, Washington, sent Profs. F. 

 Elster and H. Geitel and Herr F. Harms to Palma to 

 make observations of the electric conditions of the atmo- 

 sphere during the recent solar eclipse. By means of a self- 

 registering electrometer, the variation of atmospheric 

 electricity was photographically recorded, and a series of 

 points of the same curve was taken simultaneously bv 

 eye-readings. The lonisation of the air was studied bv a 

 " Zerstreuungsapparat, " and also by an " Ebert's Fdn- 

 counter. " Besides these observations, exact measurements 

 of the intensity of the solar radiation within the short 

 wave-lengths were carried out, a peculiar kind of photo- 

 meter having been prepared for this purpose. It is based 

 upon the property possessed by clean surfaces of the all^a- 

 line metals of emitting kathode rays of a density pro- 

 portional to the intensity of the incident light ; by these 

 rays the small residue of gas contained In a vacuum glass 

 bulb is rendered conductive, and a circuit of a current is 

 closed, the intensity of which may be read by means of a 

 d'Arsonval galvanometer. In the apparatus alluded to the 

 sensitive surface consisted of a thin layer of pure rubidium 

 metal. An accuracy of J per cent, to i per cent, was 

 easily obtained. By a blue Jena glass rays of long wave- 

 length are absorbed before reaching the rubidium surface, 

 so only the blue and violet, and partially the ultra-violet, 

 region of the spectrum remains, and these are the radi- 

 ations which may be supposed to have an ionising effect 

 on the atmospheric air. The results, as well as the de- 

 scription of the apparatus, will be published in the reports 

 of the Carnegie Institution. Unfortunately the observ- 

 ations, like all others in Spain, suffered from the bad 

 weather conditions. On the day of the eclipse rain fell 

 during the morning ; consequently it cannot be considered 

 as undisturbed with regard to atmospheric electricity. 

 The measurements of the solar radiation were possible In a 

 continuous series only from the first contact to the end 

 of totality ; the decrease of illumination, therefore, was 

 determined in a satisfactory manner and without any gaps. 

 On the other hand, clouds prevented any reading being 

 taken during the increase of light after totality. 



The photographs of the total solar eclipse, taken by the 

 Solar Physics Observatory Expedition at Palma, have 

 proved to be better than was expected from the state of 

 the sky during totality. A fine picture of the corona was 

 secured with the long-focus mirror, but the clouds were 

 too dense for successful tri-colour photographs to be 

 obtained. 



The visit of the members of the British Association to 

 the Victoria Falls on September 12 was made the occasion 

 of the formal opening of the bridge over the falls, by Prof. 



G. H. Darwin, president of the association. In declaring 

 the bridge open, Reuter's Agency reports Prof. Darwin 

 to have remarked that the great enterprise of the Cape 

 to Cairo Railway, of which the bridge is a part, had 



