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« to the Zenith of the Point H, will be equal to the 
“ Angle BET, which was, by Condru&ion, taken 
equal to the given Diftance of the Pole from the 
Zenith ; which was to be demonjirated. 
“ Now, if the Proportion of the longed: Diameter 
« of the Ellipfe B C to E F v the Didance of the Foci, 
be taken at Pleafure, one may by Calculation 
“ hnd all the Points of the Ellipfe as H, to deter- 
“ mine the Degrees by this Analogy. 
“ As FT, or BC: 
« Is to E F : : 
« So is the Sine of the Angle T ET ( the given Th* 
« fiance from the Tole to the Zenith) : 
“To the Sine of the Angle ET F, or T TiAI: 
« whofe Quantity will confequently be known. This 
cc Angle TE H being added to the Angle PET,, the 
given Diftance from the Pole to the Zenith of the 
« Point H, will give the Quantity of the Angle BEH, 
which a Line drawn from the Focus to H, the Point 
<t requir’d, makes with the Axis of the Ellipie. 
« Then in the Triangle E H F, whofe Side E F is 
known, as well as the Angle EHF, which is the 
a Double of the Angle TEH, and the Angle F E H 
16 Supplement of the Angle BEH one daall have the 
« Length of the Side E H, known in Parts of the Axis 
a 
H 
«( 
« 
« 
cc 
B C. 
« After the fame Manner, may be found the Angles 
B E I, B E V, &c. and the Length of the Lines E 1, 
E V to determine the Diftance, from the Pole to the 
Zenith of all the Degrees of the Circumference of 
dfe E mit v and in the redilinear Triangles H E I, 
1EV, whofe Sides HE, E I„E V,. are known as 
well as the Angles comprehended between the Sides 
H E, E I, 1 E, E V, which are the Differences of 
the Angles B E H, B E I, BE V, determin’d above-;, 
“ one 
