226 GERARDI REGNE RI FOCKENS 



« on Ihe quadrant pier directed to x Cygtii , and with these lemporary instrumentg I 

 « am about lo cominence a series of obscrvalioiis." 



u The advanlages I presunae Ihose instrumeuts to possess are lenghl of radius ; great 

 « sleadiness , and simplicily of conitiuction ; and beiiig used only for a few select ob. 

 « servations, these few are more likely to be raade wilh extreme carc. " 



Nihilominus quasdam per circulum fecit observaliones lucidarum Lyrae , Aquilae , 

 Cijgni, inde a Junio 1813 usque ad Febr. 1814, quas , lelescopii motu non adfeclas, 

 et omnino salis bonas, Societati offert, ut promoveant, nonvepo ut diiimant , quaoBfcioaem. 



« The question of parallax in a tlieoretical potutof view , \a scarcely of aiuy importaa- 

 « ce, it is in fact one of nierc curiosity. The tnotiun of the earlh bas long sincE ceased 

 « lo be a subject of conlroversy , and cuuid a djfierence of opinion still be suppo6ed 

 « to exist , the advocates for the Copernican System would deiive but slender gUjJfort 

 « fiora the discussion of such small variations, as form ihe subject of ihis pBj>ej!i JJut 

 « with reference to the State of pra,cUoa'l aslrouomy the case is very diffeienl ; 4r 'th^ 

 « fulure history of this branch of tlhe seienee, that period of lime will always aequipe 

 « a certain degree of celebrity , in which astronomical Instruments shall have beea 

 « brought to such a degree of perfeclion, as to exhibit distinclly the effects of parallax 

 « in Ihe fixed stars, and tp distinguish these from the variety of complicated oscillations 

 « to which, from other causes , they are perpelually subject: and as far as relates to the- 

 « natural history of ihe sidereal System (if I may so express myself ) , it is surely a sub- 

 « ject of rational curiosity to ascertain wheiher the distance of the nearest fixed star 

 « can be numerically expressed from satisfactory data, or if it be really so immeasurea- 

 « bly great, as to exceed all human powers either to conceive or delermiue. " 



Accedimus ad observaliones ipsas , quarum reductio ante paucis illustratur. 



1. ) Lyrao ». 



40 obss. Junii 22 — Augusti 21 , dant distantiam a poIo ... 51" 23' 0",278 



20 « propiores opposilioni 0, 61 



30 « hyemales 0, 867 



Differenlia ergo hyemem inter et aestatem non excedit ',6 , quae est tertia pars va- 

 rialionis B^inkleianae , imo minor etiam, quando Brinklei utaris , id est Gallica, re- 

 fractione. 



2.) Cygni a. 

 30 observaliones aestivae circiter oppositionem dant . . . 45° 22' 56",933 

 20 « hyemales circiter conjunelionem .... 57, ^9? 



Differenlia . . . 0",556 item fere tertia pars est difierentiae Brinkleianae. 



ä) Aquilae a^ 



50 



