( % ) 
ved with fuch diligence as he could wi&, and I doubt we 
have the feme caufe of complaining ftill. I know that 
Dr. Hook and Mr. Flamftead Save attempted fbmewhat 
that way , but have defined before they carae to any 
thing of Certainty. What hath been done to that pur- 
pofe abroad 1 know not. 
Galileohaxh fliggefted divers things confiderable in or- 
der to it. 
As to the times of Obfervation % That it Ihould be 
when the Sun or Earth are in the Tropicks, or as near 
thereto as may be : Becau'fe at thofe times , if any , 
will be thegreateff difference oblervable in their Meridi- 
onal Altitude. 
As to the Stars to be obferved, That they Ihould be- 
fiich as are as near as may be to the Pole of die Ec!ip- 
tick : For fuch as are in the Plain of the Ecliptick, or. 
Hear unto it, though they may be fometime nearer, fome- 
time farther from us, (which might fomewhat alter their 
apparant Magnitude, if it were fo much as to be obfer^ 
vable) yet it would little or nothing alter the Parallac- 
tick Angle, as Galileo doth there demonftrate. 
He notes alfo, that in a bufinefs fb nice, the ordinary 
Inftrumentsof Obfervation (though pretty large) would 
be inefficient (he doubts) for this purpcfe, and doth 
propofe, that by the fide of fome Edifice or Mountain, 
at fome miles diiance, the feting of fbme noted Star 
(as that of Luc'tda 'Lyra) might be obferved at thofe 
different times of the Year , which might be equiva- 
lent to an Inftrument whofe Radius were (o larg?. 
Which were a good Expedient if Pradicable ; but I 
doubt the Denfityof our Atmofphere is fb great, as that 
it will be hard to-difcern a Star juft at the Horizon, or 
even within fbme few Degrees of it: And thatthe Re- 
fraction would be-there fo great, and fo uncertain, as 
oot to comply with fo curious an Obfervation. 
That: 
