(7) == 



L 



vndc cum f fcmpcr flt ccrta fnndio ipfiiis w, quic ponatur 



:iz:U, condrui potcrit hacc acquatio diffcrcntialis : 

 ao V ~{- iV 'vu u:zz. — — . 



§. 8. Hanc igitur ob caufTam fl curua , luxta quam ^ , j 

 filum protrahitur, pro lubitu accipiatur, detcrminatio Tradoriac ^:]^ j. 

 plcrumque vires Analyfcos fuperat. At fi filum iuxta periphe- 

 riam circuli protrahatur, cuius centrum fit in C, ct radius 

 AC^zf, finguhiri fortuna cucnit, vt Tradoria dcfiniri polht. 

 Inccpcrit enim ifte motus, dum corpufculum crat in B et fi- 

 lum B A zz: a ad circulum crat normaic; nunc autcm cor- 

 pufculum pcruencrit in Z, vbi rccla tangcns ZT circulo in T 

 occurrat, ita vt fit ZT—a. lam ducla rcda CZ vocctur 

 anguius A C Z ~ oj ct C Z = s, ita vt pro Tradoria inucni- 

 cnda fit acquatio intcr rcclam z ct angulum w, quac qiiidcm 

 inucdigatio, nifi artificimn adhibcatur, iii calcuius non parum 

 molcltos induccrct. 



§. 9. Ad has difiicultatcs euitandas in calculum in- 

 troducamus angulum CZT~(p; fic enim confidcratio trian- 

 guli CZT, cuius latcra funt CZi^izs, ZTz^a ct CT — c, 



llatim praebct ccziiaa-\-zz — ^a z cof. <$, vndc dcducifur 

 z^r:i a cof. ^^rtvC^^ — ^^ fi"- ^*)i ^l^i fignum ambiguum 

 ;ul fitum pundi z rcfpicit, prouti id fucrit vcl cxtra circu- 

 lum vcl intra circulum. Quia autcm in figura punctum z 

 cxtra circulum firum rcpraclcntatur , valcbit fignum (uperius, 

 eritque z :^ a cof. (J) -H /(f ^ — ^ ^ fin. Cp'). Practcrca 

 hinc fimul innoiclcunt anguli ZCT ct ZTC; crit eniin 

 fin. Z C T — liilli^ et fin. ZTCr=l^"^. Nunc quia rcAa 



ZT c(l tingcns Tractoriae in Z, ducatur rcc^ta proxima Cs:=: 

 z-^-ozy ct ci Z dcicripto arculo zs^ in triangulo Zzs cric 



Z/ 



