842 THE POPULAR SCIENCE MONTHLY, 



spectroscopic obscrvatioDs in connection with the Coast Survey party. 

 \yhile there he made out a catalogue of 273 lines reversed in the 

 chromosphere spectrum, and 104 lines modified in the spectrum of sun- 

 spots. In 1874 he went to Peking, China, as assistant astronomer in 

 the party of Professor Watson, which observed the transit of Venus. 



While at Hanover Professor Young devoted most of the time 

 which could be spared from college duties to astronomical and spec- 

 troscopic observations, and he devised a form of automatic spectro- 

 scope w^hich has been very generally adopted, and a description of 

 which was formerly given in " The Popular Science Monthly." He 

 also made a great number of new and instructive observations on the 

 phenomena of solar prominences, and observed some remarkable ex- 

 plosions in the stupendous masses of vapor which are shot out hun- 

 dreds of thousands of miles from the solar surface. Professor Young 

 also, at this time, established what is known as Doj^pler's principle as 

 applied to light experimentally, and was enabled to measure the sun's 

 rotation by the displacement of lines in the spectrum. 



But, notwithstanding his multifarious labors in the observatory, 

 and at distant places which he visited for observation. Professor 

 Young has also been active as a writer of scientific papers, and as 

 an astronomic teacher. Besides his elaborate courses of instruc- 

 tion to college classes, he has also given courses of popular lect- 

 ures at Peabody Institute, of Baltimore, and Lowell Institute, at Bos- 

 ton. He has also delivered occasional scientific lectures in different 

 cities, and regular educational courses at Mount Holyoke Seminary, 

 Williams College, St. Paul's School, and several other places. It 

 must be added that he has also found time, within the last few years, 

 to write an excellent popular treatise on " The Sun " for the " Inter- 

 national Scientific Series," which is now just issued. 



The vigorous movement in the College of New Jersey, at Prince- 

 ton, for enlarged scientific teaching, which was inspired and directed 

 by President McCosh, led to the choice of Professor Young to take 

 the chair of Astronomy in that institution, and he accejoted the invita- 

 tion in 1877. In 1878 he was in charge of the astronomical expedition 

 organized by the college to observe the eclipse of July 29th of that year, 

 at Denver, Colorado, and in which the party had excellent success. 

 During his residence at Princeton he has maintained his customary 

 activity in pursuing spectroscopic observations in solar physics. 



Professor Young has been honored by many recognitions of emi- 

 nence in his department. He is a member of the National Academy 

 of Sciences, a Fellow and ex- Vice-President of the American Associa- 

 tion for the Advancement of Science, an Associate Fellow of the Amer- 

 ican Academy of Arts and Sciences in Boston, an Honorary Member 

 of the New York Academy of Sciences, and of the Philosophical So- 

 ciety in Philadelphia, and a Foreign Associate of the Royal Astro- 

 nomical Society of Great Britain. 



