86 NATIONAL ACADEMY OF SCIENCES 



of a protuberance fell upon the slit, so large a portion of its light was monochro- 

 matic that the hydrogen line C appeared as a bright line in the corresponding 

 portion of the spectrum. If now the slit was widened, the form of the protuber- 

 ance became visible. By placing a second slit so as to cut off all portions of the 

 spectrum except that of the line to be studied, replacing the eyepiece by a photo- 

 graphic plate, and giving similar motions to the latter and to the image of the sun 

 on the slit we have the spectroheliograph. The principal credit must be given 

 to Professor Hale for the independent invention of this instrument, for excellence 

 in the plans of its mechanical construction, for skill in its use, and for the final 

 results obtained with it, although as almost always happens, a portion of the 

 credit must be given to other astronomers who were pursuing the same line 

 of work 



" Professor Hale has shown the same skill in invention, construction, and 

 application in the other portions of his work. The problem of photographing the 

 spectra of the stars of the third and fourth types is one of unusual difficulty. 

 .... By the great light-collecting power of the 4O-inch refractor, and the use 

 of isochromatic plates, Professor Hale succeeded in photographing the spectra of 

 these stars with a large dispersion 



"During the years 1893, 1894, and 1895, Professor Hale edited the astro- 

 physical portion of Astronomy and Metaphysics. In January, 1896, he estab- 

 lished the Astrophysical Journal, associating with him the leading astrophysicists 

 of the world as assistant editors 



" The manifold duties of the director of a great observatory may not be appre- 

 ciated by one who sees only the results. To attain success good judgment, 

 patience, skill, and knowledge of a great variety of subjects are required. For 

 the establishment, erection of buildings, construction of instruments, selection of 

 officers, general plan of work, and assignment of duties, a vast amount of time 

 and energy is required before the actual scientific work begins 



" The reasons enumerated above show why the Henry Draper medal has been 

 awarded to Prof. George Ellery Hale." 89 



As would naturally be anticipated, the adhesion of the 

 National Academy to the project for an International Associa- 

 tion of Academies in 1899 soon involved it in the consideration 

 of scientific enterprises of world-wide scope. The first of these 

 was a movement for the organization of an international seismo- 

 logical association, which was brought to its attention by Sir 

 Michael Foster in 1902, in his capacity as chairman of the inter- 

 national council of the Association of Academies and as repre- 



88 For the full report, see Rep. Nat. Acad. Sci. for 1904, pp. 14-15. 



