OCTOBEK 21, 1910] 



SCIENCE 



547 



examination and report. The progress made 

 by the Department of Terrestrial Magnetism 

 of the Carnegie Institution, as shown by a 

 special report, in securing magnetic observa- 

 tions in all parts of the earth, especially on 

 the ocean areas, was very favorably com- 

 mended by a special resolution, expressing the 

 gratification of the commission in respect of 

 this efficient service. There is a disposition 

 to form as close a cooperative association as 

 practicable for the development of the research 

 into the laws of the distribution and secular 

 variation of the earth's magnetic field. From 

 personal discussion it seems evident that the 

 opinion is growing that the diurnal, annual 

 and secular variations are due to the moving 

 charges of free electricity in the atmosphere, 

 carried by the general and local circulations, 

 while the spasmodic large disturbances depend 

 upon the bombardment of ionic corpuscles 

 from the sun, and the slow oscillations of two 

 or three days' duration upon the movement of 

 ions through the gaseous upper layers of the 

 atmosphere, generally along the magnetic 

 meridians. 



On September 25 a visit was paid to the 

 observatories at Potsdam and Seddin. The 

 meteorological, magnetic, astrophysical and 

 geodetic departments at Potsdam were care- 

 fully inspected, and the ofiicials in charge gave 

 every facility for examining the apparatus. 

 •A most comprehensive and thorougiily scien- 

 tific policy prevails at Potsdam, as is well 

 known, and this, together with the beautiful 

 surroundings, made a most agreeable impres- 

 sion upon the commission. Seddin is a new 

 magnetic observatory about ten miles south- 

 west of Potsdam, and, being located in the 

 state forest area, will have protection from 

 intrusion in the future. The advance of elec- 

 tric currents towards the Potsdam site has 

 been met by the Seddin observatory for the 

 variation observations, while the absolute 

 measures are still carried on at Potsdam, to- 

 gether with such other magnetic work as is 

 found practical and convenient. 



The International Meteorological Commit- 

 ■tee met on September 26 in the same place, 

 about fifteen members being present. Pro- 

 fessor Bigelow was invited to a seat with the 



committee. Dr. W. N. Shaw was the presi- 

 dent and Dr. G. Hellmann the secretary. 

 Reports to the number of twenty were laid 

 before the committee for discussion, and some 

 of the important decisions will be mentioned. 

 It is proposed to issue an official list of ad- 

 dresses of individuals and institutions which 

 will facilitate the exchange of scientific pub- 

 lications. Steps are being taken to minimize 

 the discordant methods now prevailing in the 

 publishing of the mean values of meteorolog- 

 ical data by the different services. The propo- 

 sition to extend synoptic charts to the equator 

 was referred to the Deutsche Seewarte for 

 action. An account was given of efforts 

 made to secure prompt daily telegraph service 

 from Spain and Portugal, which project has 

 the favorable assistance of those governments. 

 The proposition from M, Koppen to adopt a 

 new absolute system of the units of measure, 

 including a specially defined barometer column 

 as the unit of length with 1,000 subdivisions, 

 was not found practicable at present. To meet 

 the requirements of the Solar Commission and 

 of the Commission of the Mondial System, it 

 was agreed that the reseau of stations already 

 selected by the commissions should be substan- 

 tially adopted, and that the directors of the 

 several services throughout the world should 

 forward promptly to Dr. W. N. Shaw, London, 

 the monthly means of the prescribed data for 

 publication by the Solar Commission within 

 the current year. These data are at present 

 to be limited to pressure, temperature, wind 

 direction and velocity at about 150 stations 

 distributed so that there shall be one for each 

 square of ten degrees of the earth's surface. 

 It may become practicable to considerably 

 increase the number of stations. This inter- 

 national scheme differs from that of the U. S. 

 Signal Service in the seventies, in that the 

 data are limited to accurately reduced monthly 

 mean values, which are to be used in connec- 

 tion with the problems in solar physics. The 

 committee approved the plan of securing accu- 

 rate data for new isothermal charts of the 

 world, but did not think it proper to prescribe 

 tlie rules of reduction, or the special years to 

 te selected for the group from which normals 

 are constructed, on account of the diversity 



