[ 479 ] 
EXAMPLE. 
Siippofe 6^:51'’ 12' 5^'^ 
AB=8y 57 51 
bC=87 20 34 
Cotangent B 9-9'^53 "Tang. | B 25“ 36' Q.6804 
Verf. line ab — bc o'* 37' 17" 5*7693 Cofine ab 8.5506 
Cofiile BC 8.6661 
ift arc o' 10" line 5.6746 2d arc 2' 43" fine 6.8971 
The difference of thefe two arcs, 2' 33" 
Subtraded from the value of the angle b, 511a 5 
- ' 
Leaves ac, 51 932 
The corredion cot. /Sx vf. fin this example is o» 
This folution is very convenient to find the diftance of 
two Zodiacal Stars, having their latitudes and difference 
of longitudCi 
SOLUTION II. 
Let T be an arcwhofe cofine cof. ^-o^-bda^bv>k^ 
tind fuppofe ac = t ^ f, then T + tz - ^ k vf. i^=bDA + dd 
=t-bda+da. Whence x v6rf. f'± cofec. t 
X cofin. ot X cofin. ^ x vf. ( 3 + cot. t x vf. f, 
This folution is ufeful to find the diftance of the Moon 
from a ftar at fome diftance from the ecliptic, in which 
cafe it coincides with the rule given by the Aftronomer 
VoL. LXV. Sff Royal, 
