( <$Ji ) 
fore the Sun comes in Conjunction with or Oppofition 
to it, if its Longitude be in the firft or laft Quadrant 
(viz,, in the afcending Semi-circle) of theEcliptick ; and 
after them, if in the defcending Semi-circle ; and it will 
appear neareft to the North Pole of the Equator, at the 
Time of that Maximum (or when the greateft Differ- 
ence between the true and apparent Declination happens) 
which precedes the Sun’s Conjunction with the 
Star. 
Thefe Particulars being fufficient for my prefent 
Purpofe, I (hall not detain you with the Recital of 
any more,, or with any farther Explication of thefe. It 
may be time enough to enlarge more upon this Head, 
when I give a Defcription of the Inftruments &c. if 
that be judged necelfary to be done; and when I fliall 
find, what I now advance, to be allowed of (as I flat- 
ter my felf it will) as fomething more than a bare Hy- 
pothecs. I have purpofely omitted fome matters of no 
great Moment, and confidered the Earth as moving in a 
Circle, and not an Ellipfe, to avoid too perplexed a 
Calculus , which after all the Trouble of it would not 
fenfibly differ from that which I make ufe of, efpecial- 
ly in thofe Confequences which I fhall at prefent draw 
from the foregoing Hypothefis. 
This being premifed, I fhall now proceed to deter- 
mine from the Obfervations,what the real Proportion is 
between the Velocity of Light and the Velocity of the 
Earth’s annual Motion in its Orbit ; upon Suppofition 
that the ‘Phenomena before mentioned do depend upon 
the Caufes I have here affigned. But I mull firft let 
you know, that in all the Obfervations hereafter men- 
tioned, I have made an Allowance for the Change of 
the Star’s Declination on Account of the Precefiion of 
R r r r 2 the 
