c *:** ) 
which are defcribed in the above-mentioned Treatife 
by more Angles and Lines. 
III. The fame Method is afterwards applied for 
to draw Tangents to Lines defcribed by other Mo- 
tions than thofe which are confidered in that Trea- 
tife ; of which the following is an Inftance. Sup- 
pofe that the Lines C P and S P revolve about the 
Poles C and S, fo that the Angle A C P bears 
always the fame invariable Proportion to ASP, 
fuppofe that of m to n. In the Line C S, take 
i> 
the Point T, fo that S T may be to C T in that 
fame Proportion of m to n ; and this Point T will 
be an invariable Point, fmce C T is toC S, as m— n 
to n. Draw T P, and conftitute the Angle S P N, 
equal to C P T, fo that P N and P T, may lie con- 
trary ways from S P and C P, and P N ihall be a 
Tangent of the Curve defcribed by the Motion of 
the Point P. Several other Theorems of this kind 
are fubjoined here. 
IV. After thefe, Lines or Angles are fuppofed to 
revolve about three or more Poles, and the Dimen- 
fions of the Curves with their Tangents and A- 
fymptotes are determined. Suppofe in the firft Place, 
U that 
