O. T. Sherman — Bright Lines in Stellar Spectra. 475 



said, were of a kind to be settled on the spot, and geological 

 brethren mutually dug in the earth and divided the debris in a 

 christian spirit. While here in Berlin, our intellects, our 

 artistic tastes, and our capacities for pleasure have all been 

 considered. Honor to the noble science of geology, which can 

 induce intelligent men such as our hosts, to provide for the 

 dead fossils from the earth's crust mansions as superb as the 

 residences of kings. (Applause.) 



The Congress was thereupon declared adjourned. 



Akt. LVIII. — Bright Lines in Stellar Spectra ; by 0. T. 



Sherman. 



Up to date, as far as my knowledge goes, bright lines have 

 been admitted to form part of the spectra of but six stars, ft 

 Lyrse, y Cassiopeias, and four small stars in Cygnus. The 

 claims of four others in Orion have been advanced and denied. 



In the recent volumes of the Nachrichten, Konkoly and 

 Gothard have called attention to the first and second of the 

 stars enumerated above. The result of the former work may 

 be summed up in the identification of the bright lines D 8 , Ha, 

 H/3, Hy, Hd, of the dark lines b, D, and a broad band in the 

 violet, and the recognition of a seven day period for the 

 variation of the spectrum of ft Lyras.* Konkoly also says :f 

 "Ich glaube auch noch manchmal im Gran und Blau einige 

 sehr zarte Linien gesehen zu haben, was aber auch eine durch 

 das Flattern des Spectrums verursachte Tauschung sein kann." 

 With a view to following these stars and learning whatever 

 a conscientious study of their spectra might show, the equa- 

 torial (8 in.) of the Yale College Observatory was devoted 

 thereto. 



The spectroscope employed is a direct vision by Duboscq ; 

 the distance from the slit to the collimating lens being about 

 14'8 cm . The train is broken into two series of three prisms 

 each. Using the single series the lines b g and b 4 are barely 

 separated. Using the double series the nickel line between D 1 

 and D 2 is seen, and b 3 is separated from b 4 by about the width 

 of the latter. The power of the eyepiece of the observing 

 telescope is about 130. A cylindrical lens behind the eye- 

 piece is usually employed. Previous to each night's work the 

 instrument was adjusted upon the sun ; a solar spot, when pos- 

 sible, being brought sharply in focus upon the jaws of the slit. 

 For stellar observation the slit was opened wide, 5 mm or more. 



* Astronomische Nachrichten, 2539, 2548, 2651, 2581. 

 f Astron. Nadir., 2548, p. 62. 



