= (98) == 



vbi manirerto nngiilum ^ femper ita afrurrere licebit, vt fiat 

 2lf^*r:i23f~"^ furrendo fcilicet ^ ~ ^W |. Quod fi ergo 

 axem boc rrodo conftituamais, ac breuitatis gratia fumamus 

 2i t" ^ — 35 f~ " ^ = r , noftra aequatio erit r~ c {e"- ^ -^^e^"- ^), 

 in qua vnica quantitas conftans c ir.efl:, vnde ob fgnum am- 

 biguum ^ duae tantum curuae diuerfae cxoriri funt cenfen- 

 dae, quas feorflm euoliii conueniet. 



r. Euoliitio cafiis r =r r (f« ^ -i- f-« ^). 



§. 36^. Hic ergo ambo cafus ante tracflati iundim oc- 

 currunt, ita vt tantum opus fit pro fmgulis elemicntis binos 

 valores fupra exhibitos coniungere, vnde fequentes formulas 

 nancifcemur: 



T — ce'''^-^ce—''^ 



X ~ li_rafm.C|)(^"^-f-«''^) — cof.(1)(f«^-f-f'-"'^)] -+- -" '- 

 y — -±—1^ cof. Cp (f«^- ^-«=I>) -^ fin. (£^"^-4- e- «<!>;] 

 t— ""^ (e^<^ — e-''^)^ '^ fin. Ct) 



aa-t-«^ ■' aa-r-i 



* = —E— U''^ -+- f-«^) — _^£_ cof. Cp. 



a a -1- I 



§. 37. Hic primum obferuo, pofita amplitudine C^-o 

 rsdium ofculi curuae in ipfo pundo a fore in: 2 ^, vbi fimul 

 coordinatae x ^t y euanefcunt. Sumta autem amiplitudine Cp 

 infinite parua, fiet j-rsi-Cp, cui applicata j debet eiTe aequa- 

 lis; abfcifTa autem .v ex formula iiotiflima, qua in ipfo ver- 

 tice a fubnormalis 5Li2. femper aequatur radio, qui hic efl 



2r, definietur: erit enim i£i-$-i$ r: 2 ^- , hincque Bjrnsf Cf^^Cp, 

 ergo integrando ;r~^Cj)C|), quare cum fit Cp — ^, erit pro 



porti- 



