90 Mr HerschePs Third Series of Observations 



twenty-five instead of twenty-two. We may then, with much 

 probability, consider a great number of pairs of stars, from 

 the first to the sixth magnitude, where the two stars are dis- 

 tant from each other from one to fifteen minutes, as being 

 systems of stars, of stars really double, visible to the naked 

 eye, and which are consequently the most brilliant and the 

 nearest to us. Such are, for example, the "Nos. 16 and 17, and 

 1 v and £ v Draconis, Dragon, Nos. 4 and 5 of Lyra, the two 

 1 a and 2 a Librae, £ Ursa? Majoris, and the well known star 

 Alcor, &c. &c. A remarkable confirmation of this opinion 

 may be drawn from the circumstance already observed by Bes- 

 sel, that some of these pairs have a common proper motion, 

 such as, for example, No. 36 Serpentarii and 30 Scorpii, and 

 the two stars above-mentioned in the last of the Great Bear. 

 But what is well worthy of remark, it frequently happens that 

 sometimes one of the stars of these pairs, and sometimes both, 

 are themselves double in the strictest meaning of the word. 



We find also very frequently three stars near each other, 

 which would not probably happen if they were distributed by 

 chance. Among the 1386 stars between the first and fifth 

 magnitude which are in the maps of Harding, the case that 

 there are three in one circle of one degree diameter, ought not 

 to take place more than a quarter of a time ; that is, it ought 

 not to occur at all. But it actually presents itself seven times, 

 or twenty-five times oftener than would be probable if it were 

 accidental. From what has now been said, therefore, we may 

 hazard the conjecture that the stars, such as the three of 8 

 Tauri, and the three of %|/ Aquarii, which we can recog- 

 nize with the naked eye, are stars physically, and not optical- 

 ly triple. 



Art. XII. — Notice of " The Third Series of Observations 

 Tenth a twenty-feet Reflecting Telescope, containing a Cata- 

 logue of 384 new Double and Multiple Stars, completing a 

 first thousand of those Objects detected in sweeps with that 

 Instrument. By J. F. W. Herschel, Esq. F.R.S. and 

 President of the Astronomical Society. 



The valuable paper, the title of which is given above, was 



