[ 1 
mined by a circular Ark 5 but it is not neceffary to 
defcribe this Cafe at prefent. 
Example: Ifmm: i :: 1000 : 22. then the greateft 
Difference of the meridional Parts in the Sphere and 
Spheroid is 76.0929 Minutes : In other Cafes it is 
found by multiplying the Remainder above mentioned 
by 1174.078. 
XV- ‘the parabolic Orbit for the Comet of 
1739. obferved by Signor Euftachio Zanotti 
at Bologna. 
T H E Motion in its own proper Orbit was retro- 
grade. 
- O t 
The Perihelion w as in . I $. 5. n. 
The defcending Node in . Y. 25. 18. 
The Perihelion from the Node 69. 53. 
d h t 
• • 
The Comet was in the Perihelion 'June 9. 9. 59. 
in the defc. Node July 18. 4. 57. 
The Perihelion of the Comet's Orbit was within 
the Sphere of the Orbit of Venus , and without that 
of the Orbit of Mercury ; being diftant from the Sun 
0,69614 Parts of the Earth's mean Diftance from the 
Sun. 
The Plane of the Orbit flood inclined to the Plane 
of the Ecliptic in an Angle of 53 0 . 25'. 
The Diurnal mean Motion, according as it is in- 
terpreted by Dr. Halley in his Elements of cometical 
Aftronomy, was i°,5707. 
XVI. A 
