f 2+0 ] 
hundreth, probably than the two hundreth part of a 
fecond; fo that it would fcarcely be diftinguifhable 
with a telefcope, upon the former fuppofition, that 
fhould magnify fix, or, upon the latter with one, that 
fhould magnify twelve thoufand times.. 
Nor can we well expebt to find their apparent 
diameters from any occultation by the moon, fince 
a diameter of the hundredth part of a fecond would 
be covered by the moon, if it entered direbtly, in lefs 
than the fiftieth part of a fecond of time, and there- 
fore a ftar can hardly enter fo obliquely, as to appear 
to vanifh by degraes* no ftar probably, which the 
moon can pafs over, fubtending an angle half fo 
great. A liar might however appear to vanifh by 
degrees in an occultation by the planet Venus, efpe- 
cially if the occultation was to happen only a little 
before or after either ftation ; but this is an event, 
which can occur fo very feldom, that little is to be 
expebted from it; and if Venus fhould be furrounded 
with an atmofphere, which is probably the cafe, it 
might very poflibly then be of no fervice at all. For 
the fame realons alfo it is probable, that nothing can 
be determined from occultations by any of the reft 
of the planets, which upon other accounts are ftill 
lefs proper for the purpofe than Venus. 
There feems to be little chance therefore of dis- 
covering with certainty the real fize of any of the 
fixed ftars, and we muft confequently be contented to 
deduce it from their parallax (if that fliould ever be 
found) and the quantity of light which they afford us, 
compared with that of the Sun. And in the mean 
time, till this parallax can be found, or fomething elle 
may rrife to furnifh us with a more general analogy, 
i we 
