[*' 8 ] 
For the Point S being on the contrary Side of the 
Centre to what it was before, it will eafily appear, 
that the Change of -f./'into —f, maft reduce one Cafe 
to the other, without any other Proof., 
Corollary . Hence, if the Number be taken equal 
to t ? or in this Cafe ^ then the Series for the 
Seftor will want the fecond Term, as in the former it 
wanted the Third. 
Definition. 
The Angle called by Kepler xhcAnomaliaEccentri , 
is a fictitious Angle in. the Elliptic Orbit of a Planet, 
being analogous to the Area defcribed by a Line from 
the Centre of the Orbit, and revolving with the 
Planet from the Line of Apfides $ in like manner as 
the Mean Anomaly is a fi£titiou$ Angle, analogous to 
the Area defcribed by a Line from the Focus. 
Otherwife, if C be the Centre, S the Focus of an 
Elliptic Orbit defcribed on the tranfverfe Axis AP, 
and the Area NSP in the Circle be taken in Pro- 
portion to the whole, as the Area defcribed in the 
Ellipfis about the Focus, to the whole : Then is the 
Arch of the Circle PN, or the Angle NCP, that 
which Kepler calls the Anomalia Eccentri . 
This Angle may be meafured either from the 
Aphelion , or from the Terihelion s in the following 
Propofition it is fuppofed to be taken from the 
Ter she lion. 
Pro- 
