MATHEMATICAL PAPERS, er 
If the procefs be trigonometrical we - — find the 
moon's altitude and — angle 2 1f 
in nius L ideis L A the arc peL cut the fe a in e= 
the moon’s longitude, and let the arc / a £. mark out her lati- 
tude ; then the point of interfection of the two arcs at p, will 
be the moon's true place or pofition. Let the vertical arc 
ZDN be drawn; then, in the triangle p »Z, the fide Z» will 
be the moon’s zenith diftance, or co-altitude, and the angle 
p9 Z her parallactic angle ; to find which, there are given two 
fides and the included angle, viz. the fide pZ= the altitude 
of the nonagefimal degree ; the fide pp — the moon's diftance 
from p one of the poles of the ecliptic = the complement of 
her latitude, and the angle Z$ D= the difference between the 
moon E bei geh the I ngitud: of the peated inl degree. 
the (eire cre pay 74, 1 pe the ‘oblique 
sia Siete pd 4 Z.into two right-angled triangles, right-an- 
gled at d: 
Pe < „Fot fide Z b E moon' S zenith ae 
A eaa ils te 
We di next find the moon's me in altitude, prepara- 
tory. to which, let the moon’s diftance from the earth in femi- 
— of the earth be found. 
52" Tn 
