4 Mr. South' s observations of the apparent distances 



The noble liberality of the Russian Government having re- 

 cently put Mr. Struve in possession of an instrument much 

 more powerful, and far more appropriate, for pursuing this 

 department of astronomical* enquiry, than those with which 

 his published observations were made, I have not deemed it 

 right, as heretofore, to refer to his earlier, yet still valuable 

 determinations, the general accuracy of which may well be 

 cited as proofs of what industry and perseverance may 

 achieve, although supported by comparatively slender instru- 

 mental assistance. 



I have said that the accompanying observations were made 

 partly at home, and partly abroad ; the latter remind me of 

 a pleasing duty : — the Board of Longitude of Paris, and 

 Government of France, have claims upon me too great to 

 remain unnoticed, the one for having requested, and the 

 other for having acceded to me the permission of introduc- 

 ing into France, free of all duty (sans conditions) j whatever 

 astronomical instruments I thought proper ;"f and so effectual 

 were the arrangements of the Director General of the 



* The investigation of parallax by direct observations of double stars, not having 

 yet been seriously entered upon, although recommended by Sir W. Herschel nearly 

 fifty years ago, and the importance of it having been warmly pressed upon me by 

 Monsieur le Marquis de la place — a continuous series of observations of the 

 most interesting double and triple stars seeming necessary — and fresh determina- 

 tions of the orbits of Saturn's satellites being wanted — it was my wish to have pro- 

 cured more extensive means than I possess, to have attacked the one, to have with 

 greater facility followed up the other, and to have furnished the necessary observa- 

 tions of the satellites alluded to ; — the overtures however for an object-glass of 

 twelve inches diameter, and twenty feet focal length (Paris measure), with which I 

 had proposed to construct an equatorial, similar to that of which an engraving is 

 given in the former paper, were most unexpectedly arrested in limine, by Mr. 

 Fraunhofer declining to supply me with one, unless accompanied by apparatus 

 provided by himself — a useless augmentation of expence, which prudence therefore did 

 not authorize me, to incur. 



f The like indulgence was granted me for the importation of my ordinary bag- 

 gage, travelling carriage, and for whatever I deemed necessary to render my sojourn 

 in France comfortable. 



