Animal Report of the Comicil. Iv 



solar eclipse of August, 1869, on which occasion he observed by 

 means of the spectroscope, which had come into prominence, 

 the green coronal line which for many years was thought to be 

 coincident with that of the Chromosphere, but which Professor 

 Young himself eventually found to be quite a distinct line. 



In 1870 he made, perhaps, his most striking discovery, that 

 of the so-called "reversing layer" of the sun. In 1871 he 

 offered his explanation of the spectrum of the solar corona, 

 which still holds the field. About this time the Spectroscope 

 as applied to the observation of " Prominences," claimed his 

 special attention, and on one occasion he was rewarded by 

 being the witness of a most extraordinary explosion near the 

 solar surface as evidenced by the shattering of a large 

 prominence. 



In 1870 he was the first to photograph solar prominences, 

 and in 1872 he completed his map of the chromospheric spectrum 

 showing 273 lines. 



In 1874 he was a member of the Government expedition 

 which observed the transit of Venus on December 8th of that 

 year at Pekin. In 1882 he observed the transit of Venus at 

 Princeton. In 1876 he applied to the sun the Doppler 

 Principle, and so determined its period of rotation by 

 spectroscopic means. 



In 1877 he was appointed Professor of Astronomy at 

 Princeton University. 



In 1881 he published his work on " The Sun," and in 1889, 

 his "General Astronomy." 



His other works include "Elements of Astronomy" (1890), 

 "Lessons in Astronomy" (1891), and " Manual of Astronomy" 

 (1902). He received numerous honours including honorary 

 degrees. In 187 1 he was elected a member of the 

 Astronomische Gesellschaft, and in 187?, an Associate of the 

 Royal Astronomical Society. He was also a member of the 

 Spectroscopic Society of Italy. In 1882 he presided over the 



