MifceUanea Curio fa. 



Concerning the Uifiance of the Fiz y d 

 Stars. By the Honourable Fran- 

 cis Roberts, Efq\ S. R. S. 



THE Ancient Aftronomers, who had no 

 other way of computing the Diftances of 

 the Heavenly Bodies, but by their Parallax to the 

 Semi-diameter of the Earth ; and being never 

 able to dtfcover any in the fix'd Stars, did from 

 thence rightly enough infer, that their Pittance 

 was very great, and much exceeding that of th«, 

 Planets, but could go no farther oc(ierwife thai} 

 by uncertain guels. 



Since the Pythagorean Syftem of the WorJ4 

 has been reviv'd by Copernicus, ( and now by 

 all Mathematicians accepted for the true one) 

 there (eem'd Ground to imagine that the Dia- 

 meter of the Earth's Annual Courfe ('which, 

 according to our beft Aftronomers, is at leaft 

 40000 times bigger than the Semi-diameter 

 of the Earth) might give a fenfible Parallax 

 to the fix'd Stars, though the other could not, 

 and thereby determine their Diftance more pre- 

 cifely. 



But though we have a Foundation to build on 

 lb vaftly exceeding that of the Ancients, there 

 are (bme Confiderations may make us fufpe£b 

 that even Jthis is not large enough for our pur- 

 pole. 



Monficur 



