546 



SCIENCE 



[X. S. Vol. XXXII. No. 825 



posal of the visitors for three nights, during 

 the first two of which excellent views were 

 had of nebulae, star clusters and planets at the 

 100-foot focus. On the third night the focal 

 plane spectrograph was exhibited in operation 

 at the 25-foot focus of the instrument. 



The Snow telescope, the 60-foot tower tele- 

 scope and the 150-foot tower telescope were 

 observed in operation on the sun, as was also 

 the equipment of the Astrophysical Station of 

 the Smithsonian Institution. 



The committee on magnitudes for the Carte 

 du Ciel and the committee on selected areas 

 took advantage of the presence of their re- 

 spective members to hold meetings. The first- 

 named body agreed on the following : 



1. That the photographic magnitudes shall 

 be perfectly independent of the visual ones. 



2. The two scales, however,' shall coincide 

 for the stars of spectral type Ao of magnitude 

 5.5 to 6.5, Harvard system. 



The several methods used at Harvard for 

 obtaining fundamental magnitudes were ex- 

 plained and discussed. Further work on such 

 fundamental photographic magnitudes is con- 

 templated by the observatories of Harvard, 

 Potsdam, Mount Wilson, Simeis and Johan- 

 nesburg. 



The committee on selected areas noted the 

 progress of their work along the following 

 lines: (1) Durchmusterung plates, (2) paral- 

 laxes, (3) proper motions, (4) additional 

 proper motion plates for the parallels of 

 — 45° and +45°, (5) visual and photo- 

 graphic standards of magnitude, (6) estimates 

 of visual magnitudes, (7) the photographic 

 magnitudes, (8) photographic magnitudes of 

 the Cape Photographic Durchmusterung, (9) 

 classification of spectra, (10) red sensitive 

 plates, (11) radial velocities, (12) sun's mo- 

 tion through space, (13) brightness of the 

 background of the sky, (14) selective absorp- 

 tion of light in space. 



On Saturday, September 3, the descent from 

 the mountain was made. That evening the 

 raembers of the conference were entertained 

 at dinner at the Maryland by Mr. and Mrs. 

 Hale. 



H. D. Babcock 



SESSIONS OF THE INTERNATIONAL COM- 

 MISSIONS FOR TERRESTRIAL MAGNET- 

 ISM, ATMOSPHERIC ELEGTRICITV 

 AND METEOROLOGY' 

 The Commission for Terrestrial Magnetism 

 and Atmospheric Electricity met in Berlin, at 

 the Royal Meteorological Institute, Professor 

 Dr. G. Hellmann, director, on September 23, 

 with about twenty members present, M. Kyk- 

 atschew, president, and Ad. Smidt, secretary. 

 The first business was the reading of a re- 

 port of progress on the work laid down by the 

 commission at Innsbruck three years ago. 

 Prominent place was given in further reports 

 to the intercomparison of standard magnetic 

 instruments, by Dubinsky, Schmidt and Chree, 

 including the observatories at Pavlovsk, Kar- 

 sani, Katharinenburg, Irkutsk, Upsala, Rude 

 Scov, Kew, Potsdam and Cheltenham. The 

 European observatories, especially in Russia, 

 agree closely together, while an unexpectedly 

 large discrepancy was reported for Chelten- 

 ham, which was accompanied by an explana- 

 tion. With the view of enlarging the net- 

 work of observatories it was intimated that 

 steps were being taken to found one or two 

 new permanent magnetic stations in Norway, 

 and one in Italy or Tunis. The establish- 

 ment of the magnetic observatory at Pilar, 

 Argentina, in connection with solar physics 

 and ionization researches, was reported. This 

 station is a few miles south of Cordoba, and 

 it is proposed to make it an important insti- 

 tution for the work of the southern hemi- 

 sphere. Professor Bigelow, recently of the 

 U. S. Weather Bureau, has been appointed to 

 this duty, and Dr. W. G. Davis, director 

 of the Meteorological Office, expects to develop 

 the equipment as rapidly as is practicable. 

 Arrangements were discussed at Berlin to 

 facilitate the exchange of magnetic curves on 

 days of large disturbances. The best methods 

 of publishing the routine magnetic data, in 

 order to meet the demands of students inter- 

 ested in solar physics and atmospheric ioniza- 

 tion, were considered, but as the subject is 

 complex it was referred to a special committee, 

 V. Everdingen, Chree, Schmidt, for further 



^ Berlin, September 23-29, 1910. 



