ANNALS OF THE ACADEMY 89 



of the Solar Union, as it is informally designated, was held on 

 Mount Wilson, California, in 1910. At this time it comprised 

 committees representing eight academies, three astrophysical 

 societies, five physical societies, and four other organizations, 

 including the International Meteorological Committee. The 

 chairman of the committee of the National Academy remarked 

 as follows, regarding the work: 



" The chief work of the union is undoubtedly the stimulation of interest in solar 

 research and the encouragement of workers in the field. It has brought together 

 astronomers and physicists on common ground, thus contributing toward the solu- 

 tion of problems lying on the borderland between these subjects. The influence of 

 the union seems to be apparent in the marked activity which has resulted in many 

 recent additions to our knowledge of the sun. But it has also accomplished much 

 in other ways. The establishment of a new system of wave lengths, based on 

 Michelson's determinations of the absolute wave length of the green cadmium 

 line, and the measurements of standard lines already made by Fabry and Buisson, 

 Eversheim, and Pfund, will be of lasting benefit to exact science. The daily pho- 

 tography of the sun, with spectroheliographs in Sicily, France, Spain, Germany, 

 England, Mexico, the United States, and India, will soon be supplemented, it is 

 hoped, by stations in Australia and China, and possibly in Japan. In this way the 

 changing phenomena of the solar atmosphere are recorded from hour to hour. A 

 program for the co-operative study of sun-spot spectra, adopted at Paris, will now 

 be revised to adapt it to the new conditions presented by recent discoveries. The 

 chief progress in the study of the intensity of the solar radiation has come 

 through the work of the Smithsonian Astrophysical Observatory, but the use in 

 Italy, France, and India of standard pyrheliometers sent out by Abbot should soon 

 result in the initiation of a general scheme of cooperation. Adams's discovery that 

 the law of the solar rotation varies at different altitudes in the sun's atmosphere 

 has been confirmed by Perot, and others are entering this important field. 

 Cooperation in eclipse observations and in other departments of solar research has 

 also been initiated by the union." 92 



The ninth volume of the Memoirs was published in 1905. 



The time for the award of the Barnard Medal having arrived 

 once more in 1905, the committee of the Academy recommended 

 that Professor Henri Becquerel be the recipient of this honor. 

 The report made at the April meeting of that year was as 

 follows : 



"Rep. Nat. Acad. Sci. for 1910, p. 18. 



