258 Royal Astronomical Society : — Prof. Bessel on the 

 1. Relative Declination of Procyon. 



Fundamenta Astron. 

 Maskelyne 



Piazzi 



Bessel 



Pond I 



Pond II 



Struve 



Argelander 



Airy 



Pond 



Henderson 



Konigsberg Obs 



Ditto,withtheRep- "I 

 sold circle j 



' For the most part but few observations of the 

 stars ; probably not altogether free from er- 

 rors of observation. 



"New edition of the Catalogue. The results of 

 separate years, which are supplied in the old 

 edition (Supplement), and the determination 

 from the later observations in Libro vi. Jl Spec. 



I R. di Palermo, give a yet somewhat greater 



(_ difference. 



Mr. Pond's own catalogue for this year. 



M. Olufsen's computations, Astr. Nachr. No. 73. 



'This is the mean of seven very beautifully ac- 

 cordant results derived from the observations 

 from 1829 to 1835. It agrees tolerably well 

 with the Catalogue of 1112 Stars; but de- 

 serves the preference, since the latter in the 

 event of a variable proper motion cannot be 

 correctly reduced to 1830. 



Astr. Nachr. No. 422. 



2. Relative Right Ascension of Sirius. 



Fundamenta Astron. 



Maskelyne 



Piazzi 



Maskelyne 



Bessel 



Pond 



Bessel 



Struve 



Argelander 



Airy 



Pond 



Konigsberg Obs. .. 



Ditto, with both "1 

 instruments... J 



rDerived from a new reduction of the observa- 

 J tions; this result differs by —0-288 from that 

 "I contained in the Catalogue for 1770 ; the rea- 

 L son of which I do not know, 

 r Derived from a new computation of the obser- 

 < vations of 1803, and agreeing nearly with the 

 [ Catalogue for 1805. 



fDerived from a new computation of the obser- 

 ■< vations, but agreeing with Mr. Pond's own 

 \_ result. 



(Tliis is the mean of seven results derived from 

 the observations from 1829 to 1835 ; it is, for 

 reasons mentioned above, preferred to the result 

 derived from the Catalogue of 1112 Stars. 



These tables show that the determinations for 1820 and 1825 are 

 fully corroborated by means of nearly contemporaneous observations 

 at other observatories, as indeed the care which has been bestowed 

 on all these observations would lead us to expect. They leave, be- 

 sides, no doubt of the continual increase of the diflference from the 

 Tabulce Regiomontance.irom 1820 to the present time. This continual 

 increase can be explained on the supposition of an unchanged proper 

 motion only by attributing errors to the determinations for 1755, 

 1820, and 1825, respectively, of sufficient magnitude to make the 



