Parallax of the Fixed Stars. 97 
how far our endeavours to render the fir ft image perfect have 
been fuccefsful. 
As foon as I was fully fatisfied that in the inveftigation of 
parallax the method of double ftars would have many advan- 
tages above any other, it became neceffary to look out for pro- 
per ftars. This introduced a new feries of obfervations. I re- 
folved to examine every ftar in the heavens, with the utmofl 
attention and a very high power, that I might collect fuch ma- 
terials for this refearch as would enable me to fix my obferva- 
tions upon thofe that would befit anfwer my end. The fuhjedt 
has already proved fo extenfive, and ftill promifes fo rich a 
harveft to thofe who are inclined to be diligent in the purfuit, 
that I cannot help inviting every lover of aftronomy to join 
with me in obfervations that muff inevitably lead to new difco- 
veries. I took fome pains to find out what double ftars had 
been recorded by aftronomers ; but my fituation permitted me 
not to confult extenfive libraries, nor indeed was it very material : 
for as I intended to view the heavens myfelf, Nature, that 
great volume, appeared to me to contain the beft catalogue 
upon this occafion. However, I remembered that the ftar in 
the head of Caftoiy that in the breaft of the Virgin, and tire 
firft ftar in Aries, had been mentioned by cassini as double 
ftars. I alfo found the Nebula in Orion w r as marked in hugen’s 
Syflema Saturnium as containing feven ftars, three of which 
(now known to be four) are very near together. With this 
fmall ftock I begun, and in the courfe of a few years obferva- 
tions have collected the ftars contained in my catalogue. I find, 
with great pleafure, that a very excellent obferver, whom I 
have the honour to call my friend*, has alfo, though un- 
» Phil. Tranf. for. the year 1781, part II. double Pars difcovered in 1779, at 
Frampton-houfe, Glamorganihire, by nat. pigott, Effi E. R. S. &c. 
Vol. LXXII. O 
known 
