( 288 ) 
<c Jbortened under the AH quator , in the Hypothecs of 
“ the oblong Spheroid , f/W in that of a perfetf 
<c Sphere. 
Having defcrib’d an oval Curve of any Kind, as 
,£ for Example, the Ellipfe * ADBE abovementioned, 
“ and infcrib’d the Circle D H E, whofe Radius is D C 
“ = half the (liorter Axis DE; upon AD take any 
Point as R, between the Equator and the Pole, and 
“ from that Point to the Evokita O TX draw the Ray 
<c _ of Qurvature^\\ which gives the Line of tendency 
<c R P {Art. IV.) Draw likewife from the common Cen- 
“ ter C, to the Circumference of the Circle D H, a Ra- 
dius CV, parallel to PR,, and meeting the Circle at Vj. 
* then from the Points R, V,draw the Lines R N, VZ, 
“ perpendicular to the Axis A B. 
“ It muft be obferv'd, Firfl % That as the Ellipfe A D 
1C reprefents a Meridian of the oblong Spheroid, the 
“ Circle D H reprefents a Meridian of a Sphere in the 
* fame Plane. 
“ Secondly , That the Point V, on the Circular Me- 
“ ridian, anfwers to the fame Degree of Latitude as 
* the Point R, upon the elliptical Meridian j becaufe 
<4 the Lines PR, C V, being parallel to each other, and 
“ perpendicular, the one to the Ellipfe and the other 
“ to the Circle (by Conjlruffion) the touching Planes* 
4S or Horizons of the Points R, V, will alfo be pa- 
* ralieL 
4< Thirdly^ Whence it follows that the Diminution of 
u the Centrifugal Force (ading againft Gravity) on ac- 
41 count of its Obliquity to the Horizon (Art. X.) of 
* Fig. iv.. 
the 
