[ 441 i 
Moreover, if* a table of natural fines Is not at hand, 
the arch AD may be found logarithmically thus [^?]. 
Take half the film of the four firQ lo- 'j 
garithms in the preceding computation ol ^ 19.53364. 
H D, viz. ] 
Dedudt the fine of half DI co IH 7.76675 
the remainder 
This remainder fought in the table' 
of logarithmic tangents gives the cor- 
refpondent fine 
This fine deducted from the firdi 
number leaves the fine of half HD, that i 
is, 19°. 59'. o". J 
PROPOSITION I. 
1 1.76689 
9.99994 
In fig. 5, 6. Let BCA be the ecliptic, E the moon 
appearing in the ecliptic in C, from the place of the 
earth whofe zenith isZj B the nonagefime degree,’ 
the arch ZB being perpendicular to the ecliptic, 
ZE C the circle of altitude ; E D the moon’s latitude, 
the arch DE being perpendicular to the ecliptic CB-j 
and DC the parallax in longitude : then D E is to the 
horizontal parallax, as the fine of Z B, the diftance qf 
the nonagefime degree from the zenith, or the altitude 
of the pole of the ecliptic, to the radius ; alfo DC is 
to the moon’s horizontal parallax as f B C X cof. Z B 
to the fquare of the radius. 
The arch C E is to the moon’s horizontal parallax 
as f. Z C to radius, and D E is to C E as f. Z B to 
f. Z C j whence by equality D E is to the horizontal 
parallax as f. Z B to the radius. 
See Philofophical Tranfadtions, VoU LI. Pi II. p. 927? 928; 
VoL. LXI. L 1 1 
