§. 41. Ante aufem inuenimus inter d^ et d yj 

 hanc rationem: ^/-v) — </ ^ cot. vp fin. -v},. qiiae relatio hic 

 introdu(fla praebet hanc aequationem ; 



— {p z-r x) cof. ^ -f- [rj - q z) fin. ^ zr 

 (^s — rjr) fin. ^ cof. -vi cor. vi/ -l- (r^— ^:s) cof. ^ cofv?/ cot,v{/ y 

 quae euohita hanc induit formam ; 



f— p (s cof ^ fin. •»4^ -f i: fin. ^ cof. y^ cof. \]y ) 7 

 j— ^ (s fin ^ fin. 4/ — 2; cof. ^ cof. y\ caf. vjy)! 

 I cx cof ^ fin. \i/ -f A- fin. ^ cof. v) cof. vj!/^ } 

 C ^ 6^ fin. 4 fin. ^ — J' cof. ^ £oL V £oI. vj/^ j, 

 fiue concinnius 



+ (rj— ^^sj^rin.i^fin.vp — cof.^cof. •vjcof. ^)? 



— (^ s — r A,-) (col.^fin. 4» -f- fin. ^ cof. >) cof. v|^)S ~~ 



Haec autem relatio eatenus tantum valct, quatenus de- 

 fcriptio arearum , feu formula v v d (^ tempori eft pro- 

 portionalis. 



§ 42, Hddenas planiim principale A O B in pla- 

 no eclipticae afl^umfimusj pro infiituto autem noftro ma- 

 gis conueniet, hoc planum ita conftituere, vt orbita pla-- 

 netae feu cometae ab eo perpetuo quam minime tantum 

 difcrepet, Teneat igitur hoc planum fitum quendam me- 

 dium mtef omnes variationes, quas orbiu quaefita fubire 



poteft. 



