48 ANNUAL RECORD OF SCIENCE AND INDUSTRY. 



available. The list was selected under the direction of As- 

 sistant C. S. Peirce, who has also given much attention to the 

 determination of the magnitudes. This list has been care- 

 fully compared with the catalogue of Heis, with the result of 

 detecting a very large number of errata, a list of which forms 

 a supplement to the catalogue of great value. The catalogue 

 lias seven columns: 1. The current number from 1 to 2164; 

 2. The number in the B. A. C. ; 3. The usual desitrnation bv 

 constellations; 4. The magnitudes as assigned by Mr. Peirce; 

 5 and 6. The approximate R. A. and o for 1880.0; and 7. 

 Synonyms and references to other authorities than the 

 B. A. C. 



SPECTRUM OBSERVATIONS OF THE STARS. 



M. D' Arrest, the Director of the Observatory at Copen- 

 hagen, writes that he continues to devote the powers of his 

 large telescope to celestial spectroscopy. His "Durchmus- 

 terung," or spectroscopic examination of the stars in the 

 northern heavens, continues to increase the number of stellar 

 spectra which belong to the third class in a far larger pro- 

 portion than any other of Secchi's four divisions. The stars 

 of this type afford remarkable objects for investigation, and 

 are pretty numerously and uniformly distributed throughout 

 the heavens. Only a few other spectra have striking simi- 

 larities among themselves. In some the position and the 

 groups of dark absorption bands are, as Secchi and Vogel 

 have stated, in complete accordance. Groups occur in which 

 even the various intensities of the bright lines are some- 

 times alike; these lines being, in general, brightest near the 

 red end, although frequently exhibiting uniform brightness 

 throughout the spectrum. But there is a remarkable uni- 

 formity in all the spectra. Out of 11,000 stars whose light 

 has been thus examined, only eighty spectra offer characteris- 

 tics worthy of special mention, and only five new stars are 

 found v\^hose spectra belong to the fourth class. On the 

 average, therefore, where there is one star of the third class 

 for every 140 stars examined, there is but one star of the 

 fourth class for every 1000 ; and this holds throughout for 

 all stars brighter than the eighth magnitude. In bright stars 

 of the third type, dark absorption bands have several times 

 been perceived. Only once, says D'Arrest, has he found a 



