24. ASTRONOMICAL AND 
For the moon’s peas d in altitude. Plate I, Fig. III. 4 
Sum of the three angles, 180° of o^. 
Angle BCA = Y's zenith diftance 7194977084 
Sum of the two unknown z’s 180-12 56 
Half fum | 54 6 28 
Side CA = )»’s diftance from the earth’s center, 6 3. 8617 
Side BC = earth’s femi-diameter, I , 
Sum.of the two fides including the es angle, -64 86 17 $ 
Their difference, SUE. R ra Siao621.86Ty '. 
The fam of the two fides E sca 
6 gra 1 8119883 
the. known angle, s Irem ic 
: Their difference, Loy 62. 8617 .1 7983861 
:: Tan getade amend the two]... pto? - "ee. 
lp e 0 29. A 7 
"unknown angles, - Li dida riche 
: Tangent + their difference, 53 15 5 Io. 1268557 
Leffer angle BAC or »'« — 51 23 
lax in altitude from fun, P 
o 
A .3083 - 
The finding of the moon’s parallax in altitude, from her true 
zenith: diftance, may be much. facilitated. by the following " 
fhort table, which I have calculated for the PM, | 
TABL E. 
