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THE 



POPULAR SCIENCE 

 MONTHLY. 



MAY, 1904.. 



THE DEVELOPMENT OF A NEW METHOD OF RESEARCH.* 



By Professor GEORGE E. HALE, 



DIRECTOR OF THE YERKES OBSERVATORY, UNIVERSITY OF CHICAGO. 



TN the fruitful field of astrophysical research there are few oppor- 

 -*- tunities for advance so promising as those afforded by the study 

 of the sun. As the central body of the solar system, maintaining the 

 planets in their orbits by the power of its attraction, and supplying 

 light and heat to the inhabitants of the earth through its radiation, 

 the sun is an object of special interest to every student of nature. Its 

 appeal to the imagination may be said to be threefold in character. 

 In the first place, because of the extraordinary nature of the phe- 

 nomena on its surface, and the stupendous scale of the eruptive dis- 

 turbances, which are becoming more and more frequent in the present 

 period of solar activity, the study of the sun for the purpose of gaining 

 an understanding of its structure is in itself a sufficiently attractive 

 object. To some, however, whose interests are aroused more particu- 

 larly by the problems of chemistry and physics than by those of as- 

 tronomy, this aspect of solar research may not possess special interest. 

 But through the development of astrophysical methods, it is precisely 

 to the physicist and the chemist that the sun should make a special 

 appeal. For the solar observer may be the spectator of physical and 

 chemical experiments on a scale far transcending any that can ever be 

 performed in the laboratory. In this enormous crucible, heated to 

 temperatures greatly exceeding those attainable by artificial means, 

 immense masses of luminous vapor, including most of the elements 

 known on the earth and many not yet discovered here, may be seen 



* Address delivered on November 23, 1903, before the University of Chicago 

 Chapter of the Society of Sigma Xi. 



