[ 8go ] 
No one, indeed, at this time of day, will ven- 
ture to aflert, that, even if no annual parallax 
could be found, after the greateft exertion of human 
art and industry, the Copernican fyftem was not, 
therefore, true; lince the quantity ol this paiallax 
may be fo fmall, as to efcape the reach of oui light, 
though aflifted to the utmoft. But though the de- 
feat of it would be no juft argument againft the Co- 
pernican fyftem, yet the aCtual demonftration of it, 
from obfervation, would be a direCt and convincing 
proof of the truth of that fyftem. 
It remains then to be confidered, what hope there 
is now left, after aftronomy has been brought to fuch 
a great degree of perfection, of being able to ftnd out 
an annual parallax in any of the fixed ftars. 
I am fenfible I may here feem to be prefumptuous, 
in venturing to treat upon this fubjedt, after the many 
accurate obfervations made by the learned Dr. Brad- 
lev, with an inftrument conftruCted for this very 
purpofe. No one can have a higher veneration than 
I have for the difcernment and exadtnefs of this il- 
luftrious aftronomer, whofe merit I have the greater 
opportunity of being acquainted with, by having the 
honour of calling him my friend. I would juft beg 
leave to take notice, that the ftars, which this albo- 
nomer obferved, were fuch only as lay within a few 
decrees of his zenith : and though his obfervations 
do^not feem to fhew a fenfible parallax in any of 
them, yet we cannot thence abfolutely conclude, that, 
amongft the great number of vifiblc ftars, theie are 
none in which it may be perceptible, till they have a 
of them, efpecially thofe of the greateft luftre, been 
obferved in proper places, near the zenith, with the 
