4-28 An Account of a General Siitvcj/ of the Heavens 



racy. If we are desirous of proceeding further, and of know- 

 ing witli certainty the places of all the stars already designated, 

 the charts must regulate oiu" further observations. 



This is a plan, the execution of which demands the greatest 

 exertions ; but which will also lead to the most useful results. 

 If it were pursued, it could not fail to furnish advantageous 

 points of comparison for comets and planets. A single com- 

 parison of a star in the heavens with the corresponding one 

 on the chart would discover any contradiction, and would 

 without doubt bring to view many new planets hitherto un- 

 known to us. Finally, the accurate knowledge of the firma- 

 ment possesses an interest for its own sake, which, to me at 

 least, appears so great, that it need not be heightened by the 

 relation of those other advantages to science to which I have 

 already alluded. 



The reasons which have determined me not to place the 

 boundary (which must be established somewhere) at the 8th 

 magnitude, are, first, that many regions of the heavens would 

 then become very barren in those stars whose places were de- 

 termined : secondly, the hope of discovering new planets, by 

 comparing the heavens with the chart, would be instantly de- 

 sti'oyed; since, of the four lately discovered planets, three at 

 least do not reach the 8 th degree of niiignitude. The rea- 

 sons against extending the boundary to the 10th magnitude, are, 

 first, the crowding of the chart and of the catalogue, which 

 would be the necessary consequence of it ; secondly, the enor- 

 mous increase of a labour which, even in its most limited ex- 

 tent, already presents an obstacle to be overcome only by the 

 most intense application ; and lastly, the difficulty of the oli- 

 servations themselves, which must be made without much illu- 

 mination of the wires in the telescope. 



I have never even had the idea of entirely completing this 

 plan ; but I have always hoped to co7itribute to it by means of 

 a new and arranged series of observations of the declinations, 

 by zones. I have consequently alwaj^s endeavoured to pro- 

 cure for myself every assistance to the prosecution of this object. 

 As the liberality of His Prussian Majesty enabled me to fur- 

 nish the observatory with a large instrument of Reichenbach, 

 I was guided in the choice of it by this object ; and I esteem 

 myself fortunate in finding in the construction of the Reichen- 

 bach meridian circle, a means of so combining this with all the 

 other objects of astronomical research as to leave nothing on 

 any point to be desired. 



This instrument was erected in March 1820; and on the 

 '19th of August 1821 the first zone was observed. The in- 

 terval of about a year and a half was almost exclusively oc- 

 cupied 



