~S4$ ) 37* ( SN^- 



qnae expreffio temporis ea ipfa eft, quam Celeb. Lambert 

 in tratfatu: Infigniores Orbitae Cometarum prbprietates 

 §. 79, exhibuit. 



§. 18. Ceternm pro determinaoda orbita parabo* 

 lica Cometae haud fuperfluum erit notaffe, fi angukis 

 ZS2 y fuerit quam minimus, femper fcre 



Nam 



y — \ - + co M9 - m y -~ i -*- ?*? — ^ 



ergo . 



cof. (« - fl) = 5? - * et cof - ( 0/ - W = ^ "" I# 

 Efl vero $'— p. zz: e — jjl-*- av, confequenter: 



cof. (0' - {jl) zz cof. (0 - p.) - 2 k fin. (0 - jfc). 

 Hinc igitur differentia binarum aequationum: 



cof. (0 - [*) = ^ - i 



cof. (0 - n) - 2 y fin. (0 - [«.) = *-$■ - i 



dat :2Kfin.(0~}JL) = ^7^ 

 at :2^cof.(a~ f JL) = ^-2V, 



hinc fumma quadratorum praebet: 



axj v — *p p(y' —y? . i i6v v P p — ifJULif 4- 4 i/ y , 



quae aequatio reducitur ad hanc : 



p(y'-y ll _l- ***P _ 4 >/ v z: o. 



y y'y' y 



Cum autem fit area minimi fecloris 



2 S Z' = i S Z. V Z' zz | V2p\ erit 

 Ijyfin. 2yzzvj// z-iQYzp, 



A a a 2 ideoque 



