and Astronomical Notices. 



365 



*• Will you favour me,*' he further says, " with your opinion 

 regarding a Pisciuin *? Annexed are all the observations accessible 

 to me, and they present strange anomalies. 



** But is it possible to pronounce the pair as constant ? I think 

 not : that would involve an error of 5° in my last sets, and of 6° in 

 Struve's observations. On the other hand, if we take the progression 

 indicated by the observations from 1819 onward, and carry it back 

 to Sir W. Herschel's time, we must then suppose that he made an 

 error of 8° or 10°, which seems inadmissible. Is it then conceivable 

 that the pair have moved nearly 180° between 1802 and 1819? 

 The ellipse being so highly elongated that this portion of the orbit 

 covers no greater area than the 4° or 5° described between 1780 

 and 1802, and a less area than that of the 10° between 1820 

 and 1850. The stars are near enough to equality, I think, to admit 

 of the hypothesis ; but we shall know more about it in a few years* 

 time." 



This passage was certainly only sent for a private opinion, not for 

 publication ; but as it seems a perfectly legitimate conclusion, and 

 one which, if it should turn out correct, strongly exemplifies the 

 propriety of Sir John Herschel's recommendation that double stars 

 should be coiistantly watched and measured, that even with the 

 slower movers, an observation every four years is not enough, — the 

 sooner it is printed, and the more extensively it is known and 

 attended to, the better for the cause of the science. 



8. Royal Observatory, Caipe of GoodHope. — Some excellent obser- 

 vations of a Centauri and other double stars of the southern hemi- 

 sphere, have also been sent home by Mr Maclear, Astronomer-Royal 

 at the Cape of Good Hope ; he expects shortly to forward the results 

 of several years' observations undertaken on stars in that neighbour- 

 hood, with the expectation of their shewing a sensible parallax. Ho 

 is likewise engaged with the meridian instruments in an extensive 

 and searching investigation into the real places of all those southern 

 stars in the British Association Catalogue, which depend on an in- 



