112 ESSAYS anp OBSERVATIONS 
vertex, CD, the lat. *, WVA a great cir- 
cle thro’ the vertex V, meeting with the 
circle of latitude in A; WD another great 
circle; VB, Vd, arches perpendicular to 
WC, WD. Then WA is a quadrant, and 
the fine of VA is the par. lon. ) 2 *, whe- 
ther the ftar has latitude or not: The 
fine of VB is the par. lat. if the ftar be in 
the ecliptic ; but, if it is in the circle WD, 
the par. lat. will be the fine of Vd; which 
may be found from the parallaxes of lon, 
and lat. given for the ecliptic place of the 
ftar: Thus, 
$, WV =Cof. VA= YR+ par. long x K—par. ion, 
R x S, VB (par. lat. | 
sn ee 
vVwi>= VWB ie CWO, if the lat. * be 
Ss, WV XS. VWS 
S, Vb —par. lat. Dée =o : 
R 
S,VWB — 
; South, 
North. 
18. Since the radius of the tables of 
fines and tangents was all along taken for 
the.horiz. par. >) 4 © or *; the parallaxes 
and equation found muft be altered pro- 
portionally. 
EXAM. 
