686 



PROGRESS OF ASTRONOMY FOR 1891 AND 1892. 



STELLAR PARALLAX. 



Prof. Pritt'hard has continued in Part iv of tbe publications of tlie 

 Oxford University Observatory liis work upon tbe photographic deter- 

 mination of stelhir paralhixes. He has conchided "from actual and 

 prolonged experience that an accuracy, amplj- sufficient in the present 

 condition of astronomy, is secured by observations of each star made 

 on twenty-five nights advantageously selected throughout the paral- 

 lactic year, four exposures being usually made on each night." 



The general result of the investigations of the parallax of thirty 

 northern stars of the second magnitude is that the average parallax of 

 a star of the second magnitude is 0."056; and comi)aring with this 

 the result of Drs. Gill and Elkin for the average parallax of fourteen 

 first magnitude stars, viz, 0."089 we see that there is distinct evidence 

 that the brighter stars are nearer — though it should be borne in mind 

 that the heliometer was used by Drs. Gill and Elkin, and the photo- 

 graphic method by Prof. Pritchard. 



Following is a tabular statement of the Oxford results. Two results 

 a and h are obtained, from two comparison stars ; the j)robable error 

 of each result is about zk0."025: 



star. 



a Anilromedfe... 

 /3 Andromeda?.-. 



a. Arietijs 



a Per.sei 



|3 I'eraei 



^ Tauri 



/3 AurigiB 



V Geminonmi.. . 

 a. Ursa; Majoris. 

 /3 Ursa? Majoris. 

 ■y UrsfB Majoris. 

 € TJrsfB Majori.s. 

 n Ursae Majoris. 



/3 Leonis 



/3 Ursai Minori.s 



a CoroniP 



y Draconis 



y Cygiii 



« Cygni 



a Pegasi 



e Pegasi 



+0. 



-h ■ 

 -I- . 



0565 

 0610 



Yale heliometer determinations of stellar lyarallax. — Dr. Elkin pub- 

 lishes the following preliminary results of his investigations of the 

 parallaxes of the first magnitude stars in the northern hemisphere, 

 proposing to continue his observations until he has secured one huu- 



