OP THE COSMOS. PERIODICALLY VARIABLE STARS. 171 



mum is quite insensible. Sometimes its variation of 

 light is still less, and scarcely noticeable. It is very red. 



19. a Hydra, R. A. 140 3', DecL-8 1'. Is of all 

 variable stars the most difficult to observe, and the period 

 is still quite unassured. Sir John Herschel gives it at 

 29 or 30 days. 



20. e Auriga, R. A. 72 48', Decl. + 43 36'. Either 

 the changes of light in this star are very irregular, or in 

 a period of several years there are several maxima and 

 minima : this can only be determined after a lapse of many 

 years. 



21. fGeminorum, A. R. 103 48', Decl.-f 20 47'. 

 Hitherto this star has shewn an entirely regular 

 course in its changes of light. At the minimum its 

 brightness is half way between v and v of the same con- 

 stellation, and at the maximum not quite equal to A ; it 

 occupies 4d. 21h. in increasing, and 5d. 6h. in decreasing. 



22. j3 Pegasi, R. A. 344 7', Decl. + 27 16'. The 

 period is already pretty well determined, but there is as 

 yet nothing to be said about the regularity or otherwise 

 of the variation of its light. 



23. Pegasi R, R. A. 344 47', Decl. + 9 43 . 



24. Cancri S, R. A. 128 50', Decl. + 19 34'. 

 There is as yet nothing to be said respecting these two 



stars. 



FR. ARGELANDER. 

 Bonn, August 1850. 



In the scientific investigation of important natural phe- 

 nomena, whether in the telluric or in the sidereal sphere of 

 the Cosmos, prudence commands us not to be too hasty in 



