206 MR. ALFRED BROTHERS^S 



ceptional cases the date (i860) is inserted, and the autho- 

 rity quoted is Secchi. The magnitudes of all the stars 

 taken from the ' Cycle ' are those given by Smyth, and 

 in many instances do not agree with the observations of 

 Dembowski and Secchi. In all other cases Secchi^s magni- 

 tudes have been adopted. 



The colours are stated on the authority of Smyth, "Webb, 

 Main, and Secchi. It may be observed that the aperture 

 of the telescope used probably influences the observer's 

 estimate of colours, as I find from information received 

 from Mr. Webb that, while using a refractor of 3*7 inches 

 aperture, his colours are often quite difierent from those 

 recorded as seen with one of 5*5 inches aperture, which 

 was used for all his observations after 1863. / 



The measures of Dembowski will be found in the 

 ' Astronomische Nachrichten,' Nos. 1473 to 1475, and 

 Nos. 1572 to 1574; and I have given the means of his 

 measures for the years. Those of Mr. Dawes are de- 

 rived from a list furnished by him^ and the same re- 

 mark applies to those of Mr. Knott. The ' Eadcliffe Ob- 

 servations' for 1 861-1863 have furnished the particulars of 

 Mr. Main's observations; and to Professor Secchi I am 

 indebted for his list of 1321 double stars measured at 

 the Observatory of the Roman College, and also for a 

 separate list by which the measures of some of the objects 

 are brought down almost to the present date. 



The measures of Mr. Morton are derived from Lord 

 Wrottesley's " Catalogue of the Positions and Distances of 

 398 Double Stars," contained in vol. xxix. of the ' Memoirs 

 of the Royal Astronomical Society of London.' Mr. Rom- 

 berg's measures are taken from the ' Leyton Astronomical 

 Observations' for 1862-64; those of Professor Kaiser 

 will be found in No. 9 of vol. xxvi. of the ' Monthly 

 Notices;' and the measures by Mr. Talmage were made at 

 Mr. Barclay's Observatory at Leyton, and supplied for the 

 purpose of this catalogue. 



