All these aloDg with Sirius and Pol- 

 lux were denominated fiery red by 

 the ancients. 



160 PROCEEDINGS OP THE ACADEMY OP 



speaks of Castor as greenish, Donati as yellow. Ihavenot access just now to the 

 volumes of the Ast. Nach. containing Schmidt's observations. 



STARS OF THE FIRST MAGNITUDE. 



Of the seventeen first magnitude stars, the changes of the colors when tabu- 

 lated, stand as follows ; the changes having been in the order they are here 

 placed, the last named being their present colors. The numerals refer to the 

 authorities below: 



1. Visible in this latitude, the 40th degree, ivhose colors have changed. 

 Sirius: red,l white,4,6 violet-blue,? green.7,8 



Capella : red,i, % 3 yellow, 4, 6 deep blue,& pale blue.5, 8 

 Vega : bluish,* white, 6 pale blue, 8 deep blue, 8 green.8 

 Procyon : yellow,* white, 6 blue.8 

 Altair : yellow,*, 6 blue.8 

 Rigel : white, 6 blue. 8 

 Spica : white, 4 , 6 blue. 8 



2. Visible in this latitude whose colors have not been known to change. 



Aldebaran : red. 

 Betelgeuze : red. 

 Antares : red. 

 Arcturus: orange yellow. 



3. Invisible in this latitude whose colors have changed, 



Alpha Crucis : growing red.9 



Eta Argus : orange yellow,! 1 deep red.io 



4. Invisible in this latitude. 



Canopus. ? 



Alpha Eridani. ? 



Beta Centauri.? 



Alpha Centauri. This is a double star, about the colors of the two com- 

 panions Sir John Herschell says, " Both of a light ruddy or orange color, 

 though that of the smaller is of a, somewhat more sombre and brownish cast. 



Authorities. 1. The ancients; Seneca, Ptolemy, <fec. 2. El Fergani. 

 3. Riccioli. 4. Humboldt. 5. Kearny. 6. Donati, quoting Schmidt. 

 7. Wilcocks. 8. Ennis. 9. Berard. 10 Gilliss. 11. Mackay. Besides these 

 authorities for first magnitude stars, there are the elder Herschell and Struve 

 for double stars not yet added to this catalogue, the younger Herschell and 

 Abbott for the six stars in Kappa Crucis, Heis for Beta Ursse Minoris, and 

 Tycho Brahe for the star of 1575 ; for the green of Castor Mr. Humboldt 

 quotes Madler in 1849, and Miss Maria Michell describes the same star as yel- 

 low in 18G3 : making in all nineteen authorities, and of a character that cannot 

 be doubted. 



Among the eleven stars of the first magnitude visible in this latitude, seven, 

 according to these evidences, have undergone changes of color, and some of 

 them more changes than one. Among the six stars of the first magnitude in 

 the southern hemisphere, not visible here, two have changed their colors, and 

 of the remainder I can say nothing. And nearly all these changes have been 

 sudden, transpiring in short periods. Moreover, none of the eleven fir3t mag- 

 nitude stars visible here are white, all are either red, yellow, green, or blue. 

 I look with a great deal of surprise on this tabular statement. Why has it 

 not been made long ago ? Probably, in great part, because changes in the 

 colors of stars could not be accounted for by any prevailing scientific theory. 

 It has been rationally assumed that the stars are similar in constitution to the 

 sun, and the sun has been encircled with a theory which affords not the least 



[June,, 



